def __init__(self, tokens, filepath):
# compilation engine init
self.lex = tokens
self.symbols = SymbolTable()
self.vm = VMWriter(filepath)
self.compile_class()
self.vm.closeout()
def __init__(self, jack_file):
self.vm_writer = VMWriter(jack_file)
self.tokenizer = JackTokenizer(jack_file)
self.symbol_table = SymbolTable()
self.if_index = -1
self.while_index = -1
def __init__(self, token_stream, out_file, xml_name):
'''
creates a new compilation engine with the given input and output.
The next method called must be compileClass().
'''
self.stream = token_stream
self.writer = VMWriter(out_file)
self.symbols = SymbolTable()
self.xml_name = xml_name
self.root = ET.Element('class')
self.stream.advance()
assert self.stream.keyword() == 'class'
def __init__(self, jack_tokenizer: JackTokenizer, output_path: str):
super().__init__()
self.tokenizer = jack_tokenizer
self.table = SymbolTable()
self.writer = VMWriter(output_path)
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
self.class_name = ''
self.curr_func_name = ''
self._if_count = 0
self._while_count = 0
self.compile_class()
def compile(self, out_fname: str) -> None:
tknizer = Tokenizer(self._jack_fname)
with VMWriter(out_fname) as writer:
self._writer = writer
token = self._compile_class(tknizer, tknizer.next_token())
if token:
raise CompilationException(
f"Expected end of file, found {token}")
def __init__(self, tokenizer: JackTokenizer, out_path: Path):
self.tokenizer = tokenizer
# Create symbol tables
self.class_level_st = SymbolTable()
self.subroutine_level_st = SymbolTable()
# class's name
self.class_name = None
self.func_name = None
self.sub_type = None
# Open the output file for writing
self.out_stream = out_path.open('w')
# Create a new VM writer for writing
self.vm_writer = VMWriter(out_path.with_suffix(".vm"))
# For generating labels
self.label_count = {"if": 0, "while": 0}
def __init__(self, input_file, output_file):
self.tokenizer = JackTokenizer(input_file)
self.out = open(output_file, 'w')
self.token = None
self.class_name = None
#######################
### PROJECT 11 CODE ###
#######################
self.symbol_table = SymbolTable()
self.vm_writer = VMWriter(output_file)
def main(argv):
"""
Main flow of program dealing with extracting files for reading and initializing files to translate into
"""
if not check_args(argv):
return
# extracting jack file to be processed
jack_files_path = argv[1]
# creating a .vm file to contain jack files translation to vm language
if os.path.isdir(jack_files_path):
for file in os.listdir(jack_files_path):
if file.endswith(".jack"):
vm_file_name = "{0}/{1}.vm".format(
jack_files_path,
os.path.splitext(os.path.basename(file))[0])
vm_writer = VMWriter(vm_file_name)
CompilationEngine('{0}/{1}'.format(jack_files_path, file),
vm_writer)
else:
vm_file_name = "{0}.vm".format(os.path.splitext(jack_files_path)[0])
vm_writer = VMWriter(vm_file_name)
CompilationEngine(jack_files_path, vm_writer)
def main():
# Input
if len(sys.argv) != 2:
raise ValueError('Invalid file name.')
input_file_path = sys.argv[1]
input_texts = get_file_text(input_file_path)
splited_input_file_path = input_file_path.split('/')
input_file_name = splited_input_file_path[-1]
# Output
output_tokenizer_file_name = '{}.xml'.format(input_file_name.split('.')[0])
output_tokenizer_file_path = '/'.join([*splited_input_file_path[:-1], output_tokenizer_file_name])
output_vm_file_name = '{}.vm'.format(input_file_name.split('.')[0])
output_vm_file_path = '/'.join([*splited_input_file_path[:-1], output_vm_file_name])
# Text Processing
del_blank_content = lambda value: value != ''
del_new_line_in_text = lambda value: value.replace('\n', '')
# 文中の // を削除して先頭と末尾と空白の文字列を削除
del_comment_in_line = lambda string: re.sub(r'//\s.*', '', string).strip()
input_texts = list(
filter(
del_blank_content, map(
del_comment_in_line, filter(
remove_comments, map(
del_new_line_in_text, input_texts
)
)
)
)
)
update_input_texts = []
for input_text in input_texts:
# プログラム中のコメントアウト (/** */) は上のテキスト処理では削除できないのでこの処理を追加
if remove_comments(input_text):
update_input_texts.append(input_text)
print('output_tokenizer_file_name: {}'.format(output_tokenizer_file_name))
print('output_vm_file_name: {}'.format(output_vm_file_name))
with VMWriter(output_vm_file_path) as vmw:
with CompilationEngine(update_input_texts, output_tokenizer_file_path, vmw) as engine:
engine.compile()
class CompilationEngine:
"""NOTE remember that "is_xxx()" checks on the next token,
and load the next token to curr_token before starting sub-methods
using "load_next_token()" and you can use values with it
"""
def __init__(self, jack_file):
self.vm_writer = VMWriter(jack_file)
self.tokenizer = JackTokenizer(jack_file)
self.symbol_table = SymbolTable()
self.if_index = -1
self.while_index = -1
# 'class' className '{' classVarDec* subroutineDec* '}'
def compile_class(self):
#! Beginning of all
# * save name of the class and move on
self.load_next_token() # 'class'
self.class_name = self.load_next_token() # className
self.load_next_token() # curr_token = '{'
# while next token == 'static' | 'field',
while self.is_class_var_dec(): # check next token
self.compile_class_var_dec() # classVarDec*
# while next_token == constructor | function | method
while self.is_subroutine_dec():
self.compile_subroutine() # subroutineDec*
self.vm_writer.close()
# ('static' | 'field' ) type varName (',' varName)* ';'
def compile_class_var_dec(self):
kind = self.load_next_token() # curr_token = static | field
type = self.load_next_token() # curr_token = type
name = self.load_next_token() # curr_token = varName
self.symbol_table.define(name, type, kind.upper())
while self.check_next_token() != ";": # (',' varName)*
self.load_next_token() # ','
name = self.load_next_token() # varName
self.symbol_table.define(name, type, kind.upper())
self.load_next_token() # ';'
# next_token = 'constructor' | 'function' | 'method'
# subroutineDec: ('constructor' | 'function' | 'method') ('void' | type) subroutineName '(' parameterList ')' subroutineBody
# subroutineBody: '{' varDec* statements '}'
def compile_subroutine(self):
subroutine_kind = (self.load_next_token()
) # ('constructor' | 'function' | 'method')
self.load_next_token() # ('void' | type)
subroutine_name = self.load_next_token() # subroutineName
self.symbol_table.start_subroutine() # init subroutine table
if subroutine_kind == "method":
self.symbol_table.define("instance", self.class_name, "ARG")
self.load_next_token() # curr_token '('
self.compile_parameter_list() # parameterList
# next_token == ')' when escaped
self.load_next_token() # ')'
self.load_next_token() # '{'
while self.check_next_token() == "var":
self.compile_var_dec() # varDec*
# NOTE next_token is neither 'var' or ';'
# NOTE next_token is statements* (zero or more)
# ANCHOR actual writing
func_name = f"{self.class_name}.{subroutine_name}" # Main.main
num_locals = self.symbol_table.counts["VAR"] # get 'var' count
self.vm_writer.write_function(func_name, num_locals)
if subroutine_kind == "constructor":
num_fields = self.symbol_table.counts["FIELD"]
self.vm_writer.write_push("CONST", num_fields)
self.vm_writer.write_call("Memory.alloc", 1)
self.vm_writer.write_pop("POINTER", 0)
elif subroutine_kind == "method":
self.vm_writer.write_push("ARG", 0)
self.vm_writer.write_pop("POINTER", 0)
# NOTE statement starts here
self.compile_statements() # statements
self.load_next_token() # '}
# ( (type varName) (',' type varName)*)?
def compile_parameter_list(self):
# curr_token == '('
if self.check_next_token() != ")":
type = self.load_next_token() # type
name = self.load_next_token() # varName
self.symbol_table.define(name, type, "ARG")
while self.check_next_token() != ")":
self.load_next_token() # ','
type = self.load_next_token() # type
name = self.load_next_token() # varName
self.symbol_table.define(name, type, "ARG")
# NOTE param compilation finishes when next_token == ')'
# 'var' type varName (',' varName)* ';'
def compile_var_dec(self):
self.load_next_token() # 'var'
type = self.load_next_token() # type
name = self.load_next_token() # # varName
self.symbol_table.define(name, type, "VAR")
while self.check_next_token() != ";": # (',' varName)*
self.load_next_token() # ','
name = self.load_next_token() # varName
self.symbol_table.define(name, type, "VAR")
self.load_next_token() # ';'
# statement*
# letStatement | ifStatement | whileStatement | doStatement | returnStatement
def compile_statements(self):
# if next_token == let | if | while | do | return
while self.is_statement():
statement = (self.load_next_token()
) # curr_token == let | if | while | do | return
if statement == "let":
self.compile_let()
elif statement == "if":
self.compile_if()
elif statement == "while":
self.compile_while()
elif statement == "do":
self.compile_do()
elif statement == "return":
self.compile_return()
# 'let' varName ('[' expression ']')? '=' expression ';'
def compile_let(self):
var_name = self.load_next_token() # curr_token == varName
var_kind = CONVERT_KIND[self.symbol_table.kind_of(var_name)]
var_index = self.symbol_table.index_of(var_name)
# if next_token == "["
if self.is_array(): # array assignment
self.load_next_token() # curr_token == '['
self.compile_expression() # expression
self.load_next_token() # curr_token == ']'
self.vm_writer.write_push(var_kind, var_index)
self.vm_writer.write_arithmetic("ADD")
self.load_next_token() # curr_token == '='
self.compile_expression() # expression
self.load_next_token() # curr_token == ';'
#! POP TEMP and PUSH TEMP location changed
self.vm_writer.write_pop("TEMP", 0)
self.vm_writer.write_pop("POINTER", 1)
self.vm_writer.write_push("TEMP", 0)
self.vm_writer.write_pop("THAT", 0)
else: # regular assignment
self.load_next_token() # curr_token == '='
self.compile_expression() # expression
self.load_next_token() # ';'
self.vm_writer.write_pop(var_kind, var_index)
# 'if' '(' expression ')' '{' statements '}' ( 'else' '{' statements '}' )?
def compile_if(self):
# curr_token == if
self.if_index += 1
if_index = self.if_index
# TODO IF indexes count separately
self.load_next_token() # curr_token == '('
self.compile_expression() # expression
self.load_next_token() # ')'
self.load_next_token() # '{'
# S = statement, L = label
self.vm_writer.write_if(f"IF_TRUE{if_index}") #! if-goto L1
self.vm_writer.write_goto(f"IF_FALSE{if_index}") #! goto L2
self.vm_writer.write_label(f"IF_TRUE{if_index}") #! label L1
self.compile_statements() # statements #! executing S1
self.vm_writer.write_goto(f"IF_END{if_index}") #! goto END
self.load_next_token() # '}'
self.vm_writer.write_label(f"IF_FALSE{if_index}") #! label L2
if self.check_next_token() == "else": # ( 'else' '{' statements '}' )?
self.load_next_token() # 'else'
self.load_next_token() # '{'
self.compile_statements() # statements #! executing S2
self.load_next_token() # '}'
self.vm_writer.write_label(f"IF_END{if_index}")
# 'while' '(' expression ')' '{' statements '}'
def compile_while(self):
# curr_token == while
self.while_index += 1
while_index = self.while_index
self.vm_writer.write_label(f"WHILE{while_index}")
self.load_next_token() # '('
self.compile_expression() # expression
self.vm_writer.write_arithmetic("NOT") # eval false condition first
self.load_next_token() # ')'
self.load_next_token() # '{'
self.vm_writer.write_if(f"WHILE_END{while_index}")
self.compile_statements() # statements
self.vm_writer.write_goto(f"WHILE{while_index}")
self.vm_writer.write_label(f"WHILE_END{while_index}")
self.load_next_token() # '}'
# 'do' subroutineCall ';'
def compile_do(self):
# curr_token == do
self.load_next_token() #! to sync with compile_term()
self.compile_subroutine_call()
self.vm_writer.write_pop("TEMP", 0)
self.load_next_token() # ';'
# 'return' expression? ';'
def compile_return(self):
# curr_token == return
if self.check_next_token() != ";":
self.compile_expression()
else:
self.vm_writer.write_push("CONST", 0)
self.vm_writer.write_return()
self.load_next_token() # ';'
# term (op term)*
def compile_expression(self):
self.compile_term() # term
while self.is_op(): # (op term)*
op: str = self.load_next_token() # op
self.compile_term() # term
if op in ARITHMETIC.keys():
self.vm_writer.write_arithmetic(ARITHMETIC[op])
elif op == "*":
self.vm_writer.write_call("Math.multiply", 2)
elif op == "/":
self.vm_writer.write_call("Math.divide", 2)
# integerConstant | stringConstant | keywordConstant | varName |
# varName '[' expression ']' | subroutineCall | '(' expression ')' | unaryOp term
def compile_term(self):
# if next_token == '~' | '-'
if self.is_unary_op_term():
unary_op = self.load_next_token() # curr_token == '~' | '-'
self.compile_term() # term (recursive)
self.vm_writer.write_arithmetic(ARITHMETIC_UNARY[unary_op])
# if next_token == '(' => '(' expression ')'
elif self.check_next_token() == "(":
self.load_next_token() # '('
self.compile_expression() # expression
self.load_next_token() # ')'
# if next_token == INTEGER(const)
elif self.check_next_type() == "INT_CONST": # integerConstant
self.vm_writer.write_push("CONST", self.load_next_token()) # )
# if next_token == STRING(const)
elif self.check_next_type() == "STRING_CONST": # stringConstant
self.compile_string()
# if next_token == KEYWORD(const)
elif self.check_next_type() == "KEYWORD": # keywordConstant
self.compile_keyword()
# varName | varName '[' expression ']' | subroutineCall
else:
#! (varName | varName for expression | subroutine)'s base
var_name = self.load_next_token(
) # curr_token = varName | subroutineCall
# (e.g. Screen.setColor | show() )
#! next_token == '[' | '(' or '.' | just varName
# varName '[' expression ']'
if self.is_array(): # if next_token == '['
self.load_next_token() # '['
self.compile_expression() # expression
self.load_next_token() # ']'
array_kind = self.symbol_table.kind_of(var_name)
array_index = self.symbol_table.index_of(var_name)
self.vm_writer.write_push(CONVERT_KIND[array_kind],
array_index)
self.vm_writer.write_arithmetic("ADD")
self.vm_writer.write_pop("POINTER", 1)
self.vm_writer.write_push("THAT", 0)
# if next_token == "(" | "." => curr_token == subroutineCall
#! if varName is not found, assume class or function name
elif self.is_subroutine_call():
# NOTE curr_token == subroutineName | className | varName
self.compile_subroutine_call()
# varName
else:
# curr_token == varName
# FIXME cannot catch subroutine call and pass it to 'else' below
# TODO error caught on Math.abs() part on Ball.vm
var_kind = CONVERT_KIND[self.symbol_table.kind_of(var_name)]
var_index = self.symbol_table.index_of(var_name)
self.vm_writer.write_push(var_kind, var_index)
# subroutineCall: subroutineName '(' expressionList ')' |
# ( className | varName) '.' subroutineName '(' expressionList ')'
# e.g.) (do) game.run()
# ! in case of 'do' order is different from 'let game = Class.new()'
def compile_subroutine_call(self):
# NOTE curr_token == subroutineName | className | varName
subroutine_caller = self.get_curr_token()
function_name = subroutine_caller
# _next_token() # FIXME now it loads '.' or '('
# func_name = identifier
number_args = 0
#! '.' or '(' 2 cases
if self.check_next_token() == ".":
self.load_next_token() # curr_token == '.'
subroutine_name = self.load_next_token(
) # curr_token == subroutineName
type = self.symbol_table.type_of(subroutine_caller)
if type != "NONE": # it's an instance
kind = self.symbol_table.kind_of(subroutine_caller)
index = self.symbol_table.index_of(subroutine_caller)
self.vm_writer.write_push(CONVERT_KIND[kind], index)
function_name = f"{type}.{subroutine_name}"
number_args += 1
else: # it's a class
class_name = subroutine_caller
function_name = f"{class_name}.{subroutine_name}"
elif self.check_next_token() == "(":
subroutine_name = subroutine_caller
function_name = f"{self.class_name}.{subroutine_name}"
number_args += 1
self.vm_writer.write_push("POINTER", 0)
self.load_next_token() # '('
number_args += self.compile_expression_list() # expressionList
self.load_next_token() # ')'
self.vm_writer.write_call(function_name, number_args)
# (expression (',' expression)* )?
def compile_expression_list(self):
number_args = 0
if self.check_next_token() != ")":
number_args += 1
self.compile_expression()
while self.check_next_token() != ")":
number_args += 1
self.load_next_token() # curr_token == ','
self.compile_expression()
return number_args
def compile_string(self):
string = self.load_next_token() # curr_token == stringConstant
self.vm_writer.write_push("CONST", len(string))
self.vm_writer.write_call("String.new", 1)
for char in string:
self.vm_writer.write_push("CONST", ord(char))
self.vm_writer.write_call("String.appendChar", 2)
def compile_keyword(self):
keyword = self.load_next_token() # curr_token == keywordConstant
if keyword == "this":
self.vm_writer.write_push("POINTER", 0)
else:
self.vm_writer.write_push("CONST", 0)
if keyword == "true":
self.vm_writer.write_arithmetic("NOT")
def is_subroutine_call(self):
return self.check_next_token() in [".", "("]
def is_array(self):
return self.check_next_token() == "["
def is_class_var_dec(self):
return self.check_next_token() in ["static", "field"]
def is_subroutine_dec(self):
return self.check_next_token() in ["constructor", "function", "method"]
def is_statement(self):
return self.check_next_token() in [
"let", "if", "while", "do", "return"
]
def is_op(self):
return self.check_next_token() in [
"+", "-", "*", "/", "&", "|", "<", ">", "="
]
def is_unary_op_term(self):
return self.check_next_token() in ["~", "-"]
def check_next_token(self):
return self.tokenizer.next_token[1]
def check_next_type(self):
return self.tokenizer.next_token[0]
def get_curr_token(self):
return self.tokenizer.curr_token[1]
def load_next_token(self):
if self.tokenizer.has_more_tokens():
self.tokenizer.advance() # curr_token = next_token
return self.tokenizer.curr_token[1]
else:
return ""
class Engine(object):
def __init__(self, tokens, filepath):
# compilation engine init
self.lex = tokens
self.symbols = SymbolTable()
self.vm = VMWriter(filepath)
self.compile_class()
self.vm.closeout()
# Routines to advance the token
def _require(self, tok, val=None):
lextok, lexval = self._advance()
if tok != lextok or tok in (T_KEYWORD, T_SYM) and val != lexval:
raise Exception(self._require_failed_msg(tok, val))
else:
return lexval
def _require_failed_msg(self, tok, val):
if val is None:
val = token_list[tok]
return 'Expected: {0}, {1} \ntoken is: {2}'.format(tok, val, self.lex.tokens)
def _advance(self):
return self.lex.advance()
def vm_function_name(self):
return self._cur_class + '.' + self._cur_subroutine
def vm_push_variable(self, name):
(type, kind, index) = self.symbols.lookup(name)
self.vm.write_push(segments[kind], index)
def vm_pop_variable(self, name):
(type, kind, index) = self.symbols.lookup(name)
self.vm.write_pop(segments[kind], index)
def load_this_ptr(self, kwd):
if kwd == KW_METHOD:
self.vm.push_arg(0)
self.vm.pop_this_ptr() # set up 'this' pointer to point to new object
elif kwd == KW_CONSTRUCTOR:
self.vm.push_const(self.symbols.var_count(SK_FIELD)) # object size
self.vm.write_call('Memory.alloc', 1)
self.vm.pop_this_ptr() # set up 'this' pointer to point to new object
def write_func_decl(self, kwd):
self.vm.write_function(self.vm_function_name(), self.symbols.var_count(SK_VAR))
self.load_this_ptr(kwd)
def write_string_const_init(self, val):
self.vm.push_const(len(val))
self.vm.write_call('String.new', 1) # String.new(len(str))
for c in val:
self.vm.push_const(ord(c))
self.vm.write_call('String.appendChar', 2) # String.appendChar(nextchar)
label_num = 0
def new_label(self):
self.label_num += 1
return 'label' + str(self.label_num)
# ------------- verify part ----------------
def _is_token(self, tok, val=None):
lextok, lexval = self.lex.peek()
return val == None and lextok == tok or (lextok, lexval) == (tok, val)
def _is_keyword(self, *keywords):
lextok, lexval = self.lex.peek()
return lextok == T_KEYWORD and lexval in keywords
def _is_sym(self, symbols):
lextok, lexval = self.lex.peek()
return lextok == T_SYM and lexval in symbols
# Variable declarations
def _is_class_var_dec(self):
return self._is_keyword(KW_STATIC, KW_FIELD)
def _is_type(self):
return self._is_token(T_ID) or self._is_keyword(KW_INT, KW_CHAR, KW_BOOLEAN)
# Subroutine declarations
def _is_subroutine(self):
return self._is_keyword(KW_CONSTRUCTOR, KW_FUNCTION, KW_METHOD)
def _is_var_dec(self):
return self._is_keyword(KW_VAR)
def _is_let(self):
return self._is_keyword(KW_LET)
def _is_if(self):
return self._is_keyword(KW_IF)
def _is_while(self):
return self._is_keyword(KW_WHILE)
def _is_do(self):
return self._is_keyword(KW_DO)
def _is_return(self):
return self._is_keyword(KW_RETURN)
def _is_statement(self):
return self._is_let() or self._is_if() or self._is_while() or self._is_do() or self._is_return()
def _is_const(self):
return self._is_token(T_NUM) or self._is_token(T_STR) or self._is_keyword_constant()
def _is_keyword_constant(self):
return self._is_keyword(KW_TRUE, KW_FALSE, KW_NULL, KW_THIS)
def _is_op(self):
return self._is_sym('+-*/&|<>=')
def _is_unary_op(self):
return self._is_sym('-~')
def _is_var_name(self):
return self._is_token(T_ID)
def _is_builtin_type(self, type):
return type in [KW_INT, KW_CHAR, KW_BOOLEAN, KW_VOID]
def _is_term(self):
return self._is_const() or self._is_var_name() or self._is_sym('(') or self._is_unary_op()
# --------------- compile part -----------------
# Parser and compile Jack code
# class: 'class' className '{' classVarDec* subroutineDec* '}'
def compile_class(self):
self._require(T_KEYWORD, KW_CLASS)
self.compile_class_name()
self._require(T_SYM, '{')
while self._is_class_var_dec():
self.compile_class_var_dec()
while self._is_subroutine():
self.compile_subroutine()
self._require(T_SYM, '}')
# className: identifier
def compile_class_name(self):
self._cur_class = self.compile_var_name() # Class names don't have to go into the symbol table
# type varName (',' varName)* ';'
def _compile_dec(self, kind):
type = self.compile_type()
name = self.compile_var_name()
self.symbols.define(name, type, kind)
while self._is_sym(','):
self._advance()
name = self.compile_var_name()
self.symbols.define(name, type, kind)
self._require(T_SYM, ';')
def compile_type(self):
"""
type: 'int' | 'char' | 'boolean' | className
"""
if self._is_type():
return self._advance()[1]
else:
raise ValueError(self._require_failed_msg(*self.lex.peek()))
# classVarDec: {'static'|'field'} type varName (',' varName)* ';'
def compile_class_var_dec(self):
tok, kwd = self._advance() # static | field
self._compile_dec(kwd_to_kind[kwd])
# varName: identifier
def compile_var_name(self):
return self._require(T_ID)
# subroutineDec: ('constructor'|'function'|'method') ('void'|type)
# subroutineName '(' parameterList ')' subroutineBody
def compile_subroutine(self):
tok, kwd = self._advance()
type = self.compile_void_or_type()
self.compile_subroutine_name()
self.symbols.start_subroutine()
if kwd == KW_METHOD:
self.symbols.define('this', self._cur_class, SK_ARG)
self._require(T_SYM, '(')
self.compile_parameter_list()
self._require(T_SYM, ')')
self.compile_subroutine_body(kwd)
# 'void' | type
def compile_void_or_type(self):
if self._is_keyword(KW_VOID):
return self._advance()[1]
else:
return self.compile_type()
# subroutineName: identifier
def compile_subroutine_name(self):
self._cur_subroutine = self.compile_var_name() # subroutine names don't have to go in the symbol table
# parameterList: (parameter (',' parameter)*)?
def compile_parameter_list(self):
if self._is_type():
self.compile_parameter()
while self._is_sym(','):
self._advance()
self.compile_parameter()
# parameter: type varName
def compile_parameter(self):
if self._is_type():
type = self.compile_type()
name = self.compile_var_name()
self.symbols.define(name, type, SK_ARG)
# subroutineBody: '{' varDec* statements '}'
def compile_subroutine_body(self, kwd):
self._require(T_SYM, '{')
while self._is_var_dec():
self.compile_var_dec()
self.write_func_decl(kwd)
self.compile_statements()
# varDec: 'var' type varName (',' varName)* ';'
def compile_var_dec(self):
self._require(T_KEYWORD, KW_VAR)
return self._compile_dec(SK_VAR)
# statement: statement*
def compile_statements(self):
while self._is_statement():
self._compile_statement()
# statement: letStatement | ifStatement | whileStatement | doStatement | returnStatement
def _compile_statement(self):
if self._is_let():
self.compile_let()
elif self._is_if():
self.compile_if()
elif self._is_while():
self.compile_while()
elif self._is_do():
self.compile_do()
elif self._is_return():
self.compile_return()
# letStatement: 'let' varName ('[' expression ']')? '=' expression ';'
def compile_let(self):
self._require(T_KEYWORD, KW_LET)
name = self.compile_var_name()
subscript = self._is_sym('[')
if subscript:
self.compile_base_plus_index(name) # calculate base+index
self._require(T_SYM, '=')
self.compile_expression() # calculate expression to assign
self._require(T_SYM, ';')
if subscript:
self.pop_array_element() # *(base+index) = expr
else:
self.vm_pop_variable(name) # pop value directly into variable
def pop_array_element(self):
self.vm.pop_temp(TEMP_ARRAY) # Pop expr value to temp register
self.vm.pop_that_ptr() # Pop base+index into 'that' register
self.vm.push_temp(TEMP_ARRAY) # Push expr back onto stack
self.vm.pop_that() # Pop value into *(base+index)
# ('[' expression ']')?
def compile_base_plus_index(self, name):
self.vm_push_variable(name) # push array ptr onto stack
self._advance()
self.compile_expression() # push index onto stack
self._require(T_SYM, ']')
self.vm.write_vm_cmd('add') # base+index - leave on the stack for later
def compile_expression(self):
self.compile_term()
# Doesn't handle normal order of operations - just left to right for now
while self._is_op():
op = self._advance()
self.compile_term()
self.vm.write_vm_cmd(vm_cmds[op[1]]) # op
# term: integerConstant | stringConstant | keywordConstant | varName
# | varName '[' expression ']' | subroutineCall | '(' expression ')'
# | unaryOp term
def compile_term(self):
if self._is_const():
self.compile_const()
elif self._is_sym('('):
self._advance()
self.compile_expression() # VM code to evaluate expression
self._require(T_SYM, ')')
elif self._is_unary_op():
tok, op = self._advance()
self.compile_term()
self.vm.write_vm_cmd(vm_unary_cmds[op]) # op
elif self._is_var_name():
tok, name = self._advance()
if self._is_sym('['):
self.compile_array_subscript(name) # VM code for array subscript
elif self._is_sym('(.'):
self.compile_subroutine_call(name) # VM code for subroutine call
else:
self.vm_push_variable(name) # push variable on stack
# integerConstant | stringConstant | keywordConstant
def compile_const(self):
tok, val = self._advance()
if tok == T_NUM:
self.vm.push_const(val) # push constant val
elif tok == T_STR:
self.write_string_const_init(val) # initialize string & push str addr
elif tok == T_KEYWORD:
self.compile_kwd_const(val) # push TRUE, FALSE, NULL etc.
# '[' expression ']'
def compile_array_subscript(self, name):
self.vm_push_variable(name) # push array ptr onto stack
self._require(T_SYM, '[')
self.compile_expression() # push index onto stack
self._require(T_SYM, ']')
self.vm.write_vm_cmd('add') # base+index
self.vm.pop_that_ptr() # pop into 'that' ptr
self.vm.push_that() # push *(base+index) onto stack
# subroutineCall: subroutineName '(' expressionList ')'
# | (className | varName) '.' subroutineName '(' expressionList ')'
def compile_subroutine_call(self, name):
(type, kind, index) = self.symbols.lookup(name)
if self._is_sym('.'):
num_args, name = self.compile_dotted_subroutine_call(name, type)
else:
num_args = 1
self.vm.push_this_ptr()
name = self._cur_class+'.'+name
self._require(T_SYM, '(')
num_args += self.compile_expr_list() # VM code to push arguments
self._require(T_SYM, ')')
self.vm.write_call(name, num_args) # call name num_args
# keywordConstant: 'true' | 'false' | 'null' | 'this'
def compile_kwd_const(self, kwd):
if kwd == KW_THIS:
self.vm.push_this_ptr()
elif kwd == KW_TRUE:
self.vm.push_const(1)
self.vm.write_vm_cmd('neg')
else: # KW_FALSE or KW_NULL
self.vm.push_const(0)
def compile_dotted_subroutine_call(self, name, type):
num_args = 0
obj_name = name
self._advance()
name = self.compile_var_name()
if self._is_builtin_type(type): # e.g. int.func(123) not allowed
ValueError('Cannot use "." operator on builtin type')
elif type == None: # Calling using class name
name = obj_name+'.'+name
else: # Calling using object variable name
num_args = 1
self.vm_push_variable(obj_name) # push object ptr onto stack
name = self.symbols.type_of(obj_name)+'.'+name
return num_args, name
# expressionList: (expression (',' expression)*)?
def compile_expr_list(self):
num_args = 0
if self._is_term():
self.compile_expression()
num_args = 1
while self._is_sym(','):
self._advance()
self.compile_expression()
num_args += 1
return num_args
# ifStatement: 'if' '(' expression ')' '{' statements '}'
# ('else' '{' statements '}')?
def compile_if(self):
self._require(T_KEYWORD, KW_IF)
end_label = self.new_label()
self._compile_cond_expression_statements(end_label) # VM code for condition and if statements
if self._is_keyword(KW_ELSE):
self._advance()
self._require(T_SYM, '{')
self.compile_statements() # VM code for else statements
self._require(T_SYM, "}")
self.vm.write_label(end_label) # label end_label
# '(' expression ')' '{' statements '}'
def _compile_cond_expression_statements(self, label):
self._require(T_SYM, '(')
self.compile_expression()
self._require(T_SYM, ')')
self.vm.write_vm_cmd('not') # ~(cond)
notif_label = self.new_label()
self.vm.write_if(notif_label) # if-goto notif_label
self._require(T_SYM, '{')
self.compile_statements() # VM code for if statements
self._require(T_SYM, '}')
self.vm.write_goto(label) # goto label
self.vm.write_label(notif_label)# label notif_label
# whileStatement: 'while' '(' expression ')' '{' statements '}'
def compile_while(self):
self._require(T_KEYWORD, KW_WHILE)
top_label = self.new_label()
self.vm.write_label(top_label) # label top_label
self._compile_cond_expression_statements(top_label) # VM code for condition and while statements
# do_statement: 'do' subroutineCall ';'
def compile_do(self):
self._require(T_KEYWORD, KW_DO)
name = self._require(T_ID)
self.compile_subroutine_call(name) # VM code for subroutine call
self.vm.pop_temp(TEMP_RETURN) # Pop return value and discard
self._require(T_SYM, ';')
# returnStatement: 'return' expression? ';'
def compile_return(self):
self._require(T_KEYWORD, KW_RETURN)
if not self._is_sym(';'):
self.compile_expression() # VM code for return expression if any
else:
self.vm.push_const(0) # push 0 if not returning a value
self._require(T_SYM, ';')
self.vm.write_return() # return
class CompilationEngine:
"""Generates the compiler's output"""
CLASS_VAR_DEC_TOKENS = ["static", "field"]
SUBROUTINE_TOKENS = ["function", "method", "constructor"]
VARIABLE_TYPES = ['int', 'char', 'boolean']
STATEMENT_TOKENS = ['do', 'let', 'while', 'return', 'if']
OP = {'+': 'ADD', '-': 'SUB', '&': 'AND', '|': 'OR', '<': 'LT', '>': 'GT', '=': 'EQ', '*': 'Math.multiply',
'/': 'Math.divide'}
def __init__(self, jack_tokenizer: JackTokenizer, output_path: str):
super().__init__()
self.tokenizer = jack_tokenizer
self.table = SymbolTable()
self.writer = VMWriter(output_path)
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
self.class_name = ''
self.curr_func_name = ''
self._if_count = 0
self._while_count = 0
self.compile_class()
def compile_class(self) -> None:
"""
Compiles a complete class
:return: None
"""
self._consume('class')
if self.tokenizer.token_type() != TokenTypes.IDENTIFIER:
raise CompilationEngineError(f"{self._get_current_token()} is an invalid token at this point. Expected a "
f"class name.")
self.class_name = self._get_current_token()
self._consume(TokenTypes.IDENTIFIER)
self._consume('{')
while self._get_current_token() != '}':
if self._get_current_token() in CompilationEngine.CLASS_VAR_DEC_TOKENS:
self.compile_class_var_dec()
elif self._get_current_token() in CompilationEngine.SUBROUTINE_TOKENS:
self.compile_subroutine_dec()
else:
raise CompilationEngineError(f"{self._get_current_token()} is an expected token at this point")
self._consume('}')
def compile_class_var_dec(self) -> None:
"""
Compiles static variable declaration, or a field declaration
:return: None.
"""
kind = str_to_kind(self._get_current_token())
self._consume(self.CLASS_VAR_DEC_TOKENS)
var_type = self._get_current_token()
self._consume_type()
self.table.define(self._get_current_token(), var_type, kind)
self._consume(TokenTypes.IDENTIFIER)
while self._get_current_token() != ';':
self._consume(',')
self.table.define(self._get_current_token(), var_type, kind)
self._consume(TokenTypes.IDENTIFIER)
self._consume(';')
def compile_subroutine_dec(self) -> None:
"""
Compiles a complete method, function or constructor.
:return: None
"""
self.table.reset()
subroutine_type = self._get_current_token()
if subroutine_type == 'method':
self.table.define('this', self.class_name, Kind.ARG) # Put this as the first arg in case it's a
# class method
self._consume(self.SUBROUTINE_TOKENS)
try:
self._consume_type()
except CompilationEngineError:
self._consume('void')
self.curr_func_name = f'{self.class_name}.{self._get_current_token()}'
self._consume(TokenTypes.IDENTIFIER)
self._consume('(')
self.compile_parameter_list()
self._consume(')')
self.compile_subroutine_body(subroutine_type)
def compile_parameter_list(self) -> None:
"""
Compiles a (possibly empty) parameter list. Doesn't handle the enclosing "()".
:return:
"""
if self._get_current_token() != ')':
var_type = self._get_current_token()
self._consume_type()
self.table.define(self._get_current_token(), var_type, Kind.ARG)
self._consume(TokenTypes.IDENTIFIER)
while self._get_current_token() != ')':
self._consume(',')
var_type = self._get_current_token()
self._consume_type()
self.table.define(self._get_current_token(), var_type, Kind.ARG)
self._consume(TokenTypes.IDENTIFIER)
def compile_subroutine_body(self, subroutine_type: str) -> None:
"""
Compiles a subroutine's body.
:return: None
"""
self._consume('{')
while self._get_current_token() == 'var':
self.compile_var_dec()
var_count = self.table.var_count(Kind.VAR)
self.writer.write_function(self.curr_func_name, var_count)
if subroutine_type == 'constructor':
n_fields = self.table.var_count(Kind.FIELD)
self.writer.write_push('CONST', n_fields)
self.writer.write_call('Memory.alloc', 1)
self.writer.write_pop('POINTER', 0)
elif subroutine_type == 'method':
self.writer.write_push('ARG', 0)
self.writer.write_pop('POINTER', 0)
while self._get_current_token() != '}':
self.compile_statements()
self._consume('}')
def compile_var_dec(self) -> None:
"""
Compiles a var declaration.
:return: None.
"""
self._consume('var')
var_type = self._get_current_token()
self._consume_type()
self.table.define(self._get_current_token(), var_type, Kind.VAR)
self._consume(TokenTypes.IDENTIFIER)
while self._get_current_token() != ';':
self._consume(',')
self.table.define(self._get_current_token(), var_type, Kind.VAR)
self._consume(TokenTypes.IDENTIFIER)
self._consume(';')
def compile_statements(self) -> None:
"""
Compiles a sequence of statements. Doesn't handle the enclosing "{}".
:return: None.
"""
while self._get_current_token() != '}':
if self._get_current_token() in self.STATEMENT_TOKENS:
getattr(self, 'compile_' + self._get_current_token())()
else:
raise CompilationEngineError(f"{self._get_current_token()} is an expected token at this point")
def compile_do(self) -> None:
"""
Compiles a do statement.
:return: None.
"""
self._consume('do')
self.compile_subroutine_call()
self.writer.write_pop('TEMP', 0) # void method
self._consume(';')
def compile_let(self) -> None:
"""
Compiles a let statement.
:return: None.
"""
self._consume('let')
name = self._get_current_token()
kind = convert_kind(self.table.kind_of(name))
index = self.table.index_of(name)
self._consume(TokenTypes.IDENTIFIER)
if self._get_current_token() == '[':
self._consume('[')
self.compile_expression()
self._consume(']')
self.writer.write_push(kind, index)
self.writer.write_arithmetic('ADD')
self.writer.write_pop('TEMP', 0)
self._consume('=')
self.compile_expression()
self.writer.write_push('TEMP', 0)
self.writer.write_pop('POINTER', 1)
self.writer.write_pop('THAT', 0)
else:
self._consume('=')
self.compile_expression()
self.writer.write_pop(kind, index)
self._consume(';')
def compile_while(self) -> None:
"""
Compiles a while statement.
:return: None.
"""
self._consume('while')
self._consume('(')
while_lbl = f"WHILE_{self._while_count}"
while_false_lbl = f"WHILE_FALSE{self._while_count}"
self._while_count += 1
self.writer.write_label(while_lbl)
self.compile_expression()
self._consume(')')
self._consume('{')
self.writer.write_if(while_false_lbl)
self.compile_statements()
self.writer.write_goto(while_lbl)
self.writer.write_label(while_false_lbl)
self._consume('}')
def compile_return(self) -> None:
"""
Compiles a return statement.
:return: None.
"""
self._consume('return')
if self._get_current_token() != ';':
self.compile_expression()
else:
self.writer.write_push('CONST', 0)
self.writer.write_return()
self._consume(';')
def compile_if(self) -> None:
"""
Compiles an if statement, possibly with a trailing else clause.
:return: None.
"""
self._consume('if')
self._consume('(')
self.compile_expression()
self._consume(')')
end_lbl = f'IF_END_{self._if_count}'
false_lbl = f'IF_FALSE_{self._if_count}'
self._if_count += 1
self._consume('{')
self.writer.write_if(false_lbl)
self.compile_statements()
self.writer.write_goto(end_lbl)
self.writer.write_label(false_lbl)
self._consume('}')
if self._get_current_token() == 'else':
self._consume('else')
self._consume('{')
self.compile_statements()
self._consume('}')
self.writer.write_label(end_lbl)
def compile_expression(self) -> None:
"""
Compiles an expression.
:return: None
"""
self.compile_term()
while self._get_current_token() in self.OP:
op = self._get_current_token()
self._consume(op)
self.compile_term()
if op == '*':
self.writer.write_call('Math.multiply', 2)
elif op == '/':
self.writer.write_call('Math.divide', 2)
else:
self.writer.write_arithmetic(self.OP[op])
def compile_term(self) -> None:
"""
Compiles a term. If the current token is an identifier, the routine must distinguish between a variable,
an array entry, or a subroutine call.
:return: None.
"""
token_type = self.tokenizer.token_type()
if token_type == TokenTypes.IDENTIFIER:
curr_token = self._get_current_token()
self.tokenizer.advance()
if self._get_current_token() in ('(', '.'):
self.compile_subroutine_call(curr_token)
elif self._get_current_token() == '[':
self._consume('[')
self.compile_expression()
self._consume(']')
kind = convert_kind(self.table.kind_of(curr_token))
index = self.table.index_of(curr_token)
self.writer.write_push(kind, index)
self.writer.write_arithmetic('ADD')
self.writer.write_pop('POINTER', 1)
self.writer.write_push('THAT', 0)
else:
kind = convert_kind(self.table.kind_of(curr_token))
index = self.table.index_of(curr_token)
self.writer.write_push(kind, index)
elif token_type == token_type.INT_CONST:
self.writer.write_push('CONST', int(self._get_current_token()))
self._consume(token_type)
elif token_type == token_type.KEYWORD:
curr_token = self._get_current_token()
if curr_token in ['true', 'false', 'null']:
self.writer.write_push('CONST', 0)
if curr_token == 'true':
self.writer.write_arithmetic('NOT')
if curr_token == 'this':
self.writer.write_push('POINTER', 0)
self._consume(token_type)
elif token_type == token_type.STRING_CONST:
const_str = ''
first = True
while const_str.count('"') < 2:
if first:
const_str += self._get_current_token()
first = False
else:
const_str += ' ' + self._get_current_token()
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
const_str = const_str.replace('"', '')
self.writer.write_push('CONST', len(const_str))
self.writer.write_call('String.new', 1)
for char in const_str:
self.writer.write_push('CONST', ord(char))
self.writer.write_call('String.appendChar', 2)
else:
if self._get_current_token() == '(':
self._consume('(')
self.compile_expression()
self._consume(')')
else:
op = self._get_current_token()
self._consume(['-', '~']) # unaryOp term
self.compile_term()
if op == '-':
self.writer.write_arithmetic('NEG')
else:
self.writer.write_arithmetic('NOT')
def compile_subroutine_call(self, subroutine_name=None) -> None:
n_args = 0
if not subroutine_name:
subroutine_name = self._get_current_token()
self._consume(TokenTypes.IDENTIFIER)
if self._get_current_token() == '.':
self._consume('.')
sub_name = self._get_current_token()
self._consume(TokenTypes.IDENTIFIER)
try: # Instance
var_type = self.table.type_of(subroutine_name)
kind = convert_kind(self.table.kind_of(subroutine_name))
index = self.table.index_of(subroutine_name)
self.writer.write_push(kind, index)
func_name = f'{var_type}.{sub_name}'
except KeyError: # Class
func_name = f'{subroutine_name}.{sub_name}'
else:
func_name = f'{self.class_name}.{subroutine_name}'
n_args += 1
self.writer.write_pop('POINTER', 0)
self._consume('(')
n_args += self.compile_expression_list()
self._consume(')')
self.writer.write_call(func_name, n_args)
def compile_expression_list(self) -> int:
"""
Compiles a (possibly empty) comma-separated list of expressions.
:return: Int. Number of arguments.
"""
n_args = 0
if self._get_current_token() != ')':
self.compile_expression()
n_args += 1
while self._get_current_token() == ',':
self._consume(',')
self.compile_expression()
n_args += 1
return n_args
@singledispatchmethod
def _consume(self, expected) -> None:
"""
Check if the current token matches what it's expected to be. Either by value or by type.
In case of a match, the function will advance to the next token.
Otherwise the function will raise CompilationEngineError.
:return: None
"""
raise TypeError("Unsupported type: ", type(expected))
@_consume.register(str)
@_consume.register(list)
def _(self, expected_tokens) -> None:
"""Consume by value"""
if not isinstance(expected_tokens, list):
expected_tokens = [expected_tokens]
curr_token = self._get_current_token()
if curr_token not in expected_tokens:
raise CompilationEngineError(f"Expected {expected_tokens} but current token is {curr_token}. "
f"Compilation failed.")
else:
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
@_consume.register
def _(self, expected_types: TokenTypes):
"""Consume by type"""
if not isinstance(expected_types, list):
expected_types = [expected_types]
curr_type = self.tokenizer.token_type()
if curr_type not in expected_types:
raise CompilationEngineError(f"Expected {expected_types} but current token type is {curr_type}. "
f"Compilation failed.")
else:
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
def _consume_type(self):
"""
Int / char / boolean / class name
:return: None.
"""
try:
self._consume(self.VARIABLE_TYPES)
except CompilationEngineError:
self._consume(TokenTypes.IDENTIFIER) # Class name
def _get_current_token(self) -> str:
token_type = self.tokenizer.token_type()
if token_type is TokenTypes.INT_CONST:
curr_token = str(self.tokenizer.int_val())
elif token_type is TokenTypes.KEYWORD:
curr_token = self.tokenizer.key_word()
else:
curr_token = self.tokenizer.current_token
return curr_token
def __init__(self, source, destination): self.src = source self.dst = destination self.writer = VMWriter(destination) self.iter = Lookahead(tokenizor.newTokenizor(self.src)) self._symbol_table = SymbolTable()
class CompilationEngine:
def __init__(self, source, destination):
self.src = source
self.dst = destination
self.writer = VMWriter(destination)
self.iter = Lookahead(tokenizor.newTokenizor(self.src))
self._symbol_table = SymbolTable()
def compile(self):
root = self._compileClass()
return root
def _compileClass(self):
classE = Element(ELEMENTS.CLASS)
self._readKeyword(classE, ELEMENTS.CLASS)
self.className = self._readIdentifier(classE)
self._readSymbol(classE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileClassVarDec(classE)
self._compileSubroutine(classE)
self._readSymbol(classE, _SYMBOLS.BRACKET_CURLY_CLOSE)
return classE
def _compileClassVarDec(self, parent):
while self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _CLASSVARDEC.FIELD_TYPES:
classVarDecE = Element(ELEMENTS.CLASSVARDEC)
self._readKeyword(classVarDecE)
self._readType(classVarDecE)
self._readIdentifier(classVarDecE)
while self._readSymbolOptional(classVarDecE, _SYMBOLS.COMMA):
self._readIdentifier(classVarDecE)
self._readSymbol(classVarDecE, _SYMBOLS.SEMI_COLON)
parent.append(classVarDecE)
def _compileSubroutine(self, parent):
while self.nextTok and self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _SUBROUTINEDEC.TYPES:
subroutineDecE = Element(ELEMENTS.SUBROUTINEDEC)
function_type = self._readKeyword(subroutineDecE)
self._readReturnType(subroutineDecE)
self.methodName = self._readIdentifier(subroutineDecE)
self._symbol_table.startSubroutine(self.className, self.methodName)
if function_type == _SUBROUTINEDEC.METHOD:
self._symbol_table.define("this", self.className, SYM_KINDS.ARG)
self._uid = -1
self._readSymbol(subroutineDecE, _SYMBOLS.PARENTHESES_OPEN)
self._compileParameters(subroutineDecE)
self._readSymbol(subroutineDecE, _SYMBOLS.PARENTHESES_CLOSE)
self._compileSubroutineBody(subroutineDecE, function_type)
parent.append(subroutineDecE)
def _gen_label(self, type_):
self._uid += 1
return "%s.%s.%s.%d" % (self.className, self.methodName, type_, self._uid)
def _gen_labels(self, *parts):
self._uid += 1
return ["%s.%s.%s.%d" % (self.className, self.methodName, part, self._uid) for part in parts]
def _compileSubroutineBody(self, parent, function_type):
bodyE = Element(ELEMENTS.SUBROUTINEBODY)
self._readSymbol(bodyE, _SYMBOLS.BRACKET_CURLY_OPEN)
nArgs = self._compileVarDec(bodyE)
function_name = parent[2].text
function_full_name = "%s.%s" % (self.className, function_name)
self.writer.writeFunction(function_full_name, nArgs)
if function_type == _SUBROUTINEDEC.CONSTRUCTOR:
field_count = self._symbol_table.varCount(SYM_KINDS.FIELD)
self.writer.writePush(SEGMENT.CONST, field_count)
self.writer.writeCall("Memory.alloc", 1)
self.writer.writePop(SEGMENT.POINTER, 0)
elif function_type == _SUBROUTINEDEC.METHOD:
self.writer.writePush(SEGMENT.ARG, 0)
self.writer.writePop(SEGMENT.POINTER, 0)
self._compileStatements(bodyE)
self._readSymbol(bodyE, _SYMBOLS.BRACKET_CURLY_CLOSE)
parent.append(bodyE)
def _compileStatements(self, parent):
statementsE = Element(ELEMENTS.STATEMENTS)
while self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _STATEMENTS.TYPE_NAMES:
if self.nextTok.value == _STATEMENTS.LET:
statementE = Element(ELEMENTS.STATEMENT_LET)
self._readKeyword(statementE)
identifier = self._readIdentifier(statementE)
is_array = False
if self._readSymbolOptional(statementE, _SYMBOLS.BRACKET_OPEN):
is_array = True
self._compileExpression(statementE)
self.writer.writePush(*self._identifier_data(identifier))
self.writer.writeArithmetic("add")
self._readSymbol(statementE, _SYMBOLS.BRACKET_CLOSE)
self._readSymbol(statementE, _SYMBOLS.EQUAL)
self._compileExpression(statementE)
self._readSymbol(statementE, _SYMBOLS.SEMI_COLON)
if is_array:
self.writer.writePop(SEGMENT.TEMP, 0)
self.writer.writePop(SEGMENT.POINTER, 1)
self.writer.writePush(SEGMENT.TEMP, 0)
self.writer.writePop(SEGMENT.THAT, 0)
else:
self.writer.writePop(*self._identifier_data(identifier))
statementsE.append(statementE)
elif self.nextTok.value == _STATEMENTS.IF:
label_else, label_end = self._gen_labels("if.else", "if.end")
statementE = Element(ELEMENTS.STATEMENT_IF)
self._readKeyword(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_OPEN)
self._compileExpression(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_CLOSE)
self.writer.writeArithmetic("not")
self.writer.writeIf(label_else)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileStatements(statementE)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_CLOSE)
self.writer.writeGoto(label_end)
self.writer.writeLabel(label_else)
if self._readKeywordOptional(statementE, _KEYWORDS.ELSE):
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileStatements(statementE)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_CLOSE)
self.writer.writeLabel(label_end)
statementsE.append(statementE)
elif self.nextTok.value == _STATEMENTS.WHILE:
label_start, label_end = self._gen_labels("while.start", "while.end")
self.writer.writeLabel(label_start)
statementE = Element(ELEMENTS.STATEMENT_WHILE)
self._readKeyword(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_OPEN)
self._compileExpression(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_CLOSE)
self.writer.writeArithmetic("not")
self.writer.writeIf(label_end)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileStatements(statementE)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_CLOSE)
statementsE.append(statementE)
self.writer.writeGoto(label_start)
self.writer.writeLabel(label_end)
elif self.nextTok.value == _STATEMENTS.DO:
self._compileDo(statementsE)
elif self.nextTok.value == _STATEMENTS.RETURN:
statementE = Element(ELEMENTS.STATEMENT_RETURN)
self._readKeyword(statementE)
if not (self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == _SYMBOLS.SEMI_COLON):
self._compileExpression(statementE)
else:
self.writer.writePush(SEGMENT.CONST, 0)
self._readSymbol(statementE, _SYMBOLS.SEMI_COLON)
self.writer.writeReturn()
statementsE.append(statementE)
if len(statementsE) == 0:
statementsE.text = "\n"
parent.append(statementsE)
def _compileExpression(self, parent):
expressionE = Element(ELEMENTS.EXPRESSION)
self._readTerm(expressionE)
while self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value in _SYMBOLS.OPERATORS:
symbol = self._readSymbol(expressionE)
self._readTerm(expressionE)
self.writer.writeArithmetic(symbol)
parent.append(expressionE)
def _compileExpressionList(self, parent):
self._readSymbol(parent, _SYMBOLS.PARENTHESES_OPEN)
expListE = Element(ELEMENTS.EXPRESSION_LIST)
nArgs = 0
while not (self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == _SYMBOLS.PARENTHESES_CLOSE):
self._compileExpression(expListE)
self._readSymbolOptional(expListE, _SYMBOLS.COMMA)
nArgs += 1
# hack for TextComparer
if len(expListE) == 0:
expListE.text = "\n"
parent.append(expListE)
self._readSymbol(parent, _SYMBOLS.PARENTHESES_CLOSE)
return nArgs
def _compileDo(self, parent):
statementE = Element(ELEMENTS.STATEMENT_DO)
self._readKeyword(statementE, _STATEMENTS.DO)
identifier = self._readIdentifier(statementE)
nArgs = 0
if self._readSymbolOptional(statementE, _SYMBOLS.DOT):
type_ = self._symbol_table.typeOf(identifier)
if type_:
segment, index = self._identifier_data(identifier)
self.writer.writePush(segment, index)
nArgs += 1
identifier = "%s.%s" % (type_, self._readIdentifier(statementE))
else:
identifier = "%s.%s" % (identifier, self._readIdentifier(statementE))
else:
identifier = "%s.%s" % (self.className, identifier)
self.writer.writePush(SEGMENT.POINTER, 0)
nArgs += 1
nArgs += self._compileExpressionList(statementE)
self._readSymbol(statementE, _SYMBOLS.SEMI_COLON)
self.writer.writeCall(identifier, nArgs)
self.writer.writePop(SEGMENT.TEMP, 0)
parent.append(statementE)
def _compileVarDec(self, parent):
nArgs = 0
while self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value == _KEYWORDS.VAR:
varDecE = Element(ELEMENTS.VAR_DEC)
self._readKeyword(varDecE, _KEYWORDS.VAR)
self._readType(varDecE)
self._readIdentifier(varDecE)
nArgs += 1
while self._readSymbolOptional(varDecE, _SYMBOLS.COMMA):
self._readIdentifier(varDecE)
nArgs += 1
self._readSymbol(varDecE, _SYMBOLS.SEMI_COLON)
parent.append(varDecE)
return nArgs
def _compileParameters(self, parent):
paramListE = Element(ELEMENTS.PARAM_LIST)
while (self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _CLASSVARDEC.VAR_TYPES) or self.nextTok.type == tokenizor.IDENTIFIER:
self._readType(paramListE)
self._readIdentifier(paramListE)
self._readSymbolOptional(paramListE, _SYMBOLS.COMMA)
if len(paramListE) == 0:
paramListE.text = "\n"
parent.append(paramListE)
##############################
########## READ ##############
##############################
def _readTerm(self, parent):
termE = Element(ELEMENTS.TERM)
if self.nextTok.type == tokenizor.INTEGER:
self.next()
termE.append(_leafElement(ELEMENTS.INTEGER_CONSTANT, self.tok.value))
self.writer.writePush(SEGMENT.CONST, self.tok.value)
elif self.nextTok.type == tokenizor.STRING:
self.next()
termE.append(_leafElement(ELEMENTS.STRING_CONSTANT, self.tok.value))
string_value = self.tok.value
self.writer.writePush(SEGMENT.CONST, len(string_value))
self.writer.writeCall("String.new", 1)
for char in string_value:
self.writer.writePush(SEGMENT.CONST, ord(char))
self.writer.writeCall("String.appendChar", 2)
elif self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _KEYWORDS.CONSTANTS:
self.next()
termE.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
_KW_CONT_WRITE[self.tok.value](self.writer)
elif self.nextTok.type == tokenizor.IDENTIFIER:
identifier = self._readIdentifier(termE)
nArgs = 0
if self._readSymbolOptional(termE, _SYMBOLS.BRACKET_OPEN):
self._compileExpression(termE)
self.writer.writePush(*self._identifier_data(identifier))
self.writer.writeArithmetic("add")
self.writer.writePop(SEGMENT.POINTER, 1)
self.writer.writePush(SEGMENT.THAT, 0)
self._readSymbol(termE, _SYMBOLS.BRACKET_CLOSE)
elif self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == _SYMBOLS.PARENTHESES_OPEN:
nArgs = self._compileExpressionList(termE)
self._readSymbol(termE, _SYMBOLS.PARENTHESES_CLOSE)
self.writer.writeCall(identifier, nArgs)
elif self._readSymbolOptional(termE, _SYMBOLS.DOT):
type_ = self._symbol_table.typeOf(identifier)
if type_:
segment, index = self._identifier_data(identifier)
self.writer.writePush(segment, index)
nArgs += 1
identifier = "%s.%s" % (type_, self._readIdentifier(termE))
else:
identifier = "%s.%s" % (identifier, self._readIdentifier(termE))
nArgs += self._compileExpressionList(termE)
self.writer.writeCall(identifier, nArgs)
else:
self.writer.writePush(*self._identifier_data(identifier))
elif self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == _SYMBOLS.PARENTHESES_OPEN:
self.next()
termE.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
self._compileExpression(termE)
self._readSymbol(termE, _SYMBOLS.PARENTHESES_CLOSE)
elif self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value in _SYMBOLS.UNARY_OPARTORS:
self.next()
sym = self.tok.value
termE.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
self._readTerm(termE)
self.writer.writeArithmeticUnary(sym)
else:
raise self._syntaxError("Unexpected %s." % self.tok.value)
parent.append(termE)
def _identifier_data(self, identifier):
return _SEG_TRANSLATE[self._symbol_table.kindOf(identifier)], self._symbol_table.indexOf(identifier)
def _readIdentifier(self, parent):
self.next()
self._assertToken(self.tok, ELEMENTS.IDENTIFIER, type_=tokenizor.IDENTIFIER)
name = self.tok.value
element = _leafElement(ELEMENTS.IDENTIFIER, name)
type_ = self._symbol_table.typeOf(name)
kind = None
index = None
if type_ is None:
if parent.tag in (ELEMENTS.CLASSVARDEC, ELEMENTS.VAR_DEC) and len(parent) > 1:
type_ = parent[1].text
kind = _SYM_KIND_MAP[parent[0].text]
elif parent.tag == ELEMENTS.PARAM_LIST and len(parent) > 0:
type_ = parent[-1].text
kind = SYM_KINDS.ARG
if kind is not None:
index = self._symbol_table.define(name, type_, kind)
else:
type_ = self._symbol_table.typeOf(name)
kind = self._symbol_table.kindOf(name)
index = self._symbol_table.indexOf(name)
if kind is not None:
element.set("type", type_)
element.set("kind", str(kind))
element.set("index", str(index))
parent.append(element)
return name
def _readType(self, parent):
if self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _CLASSVARDEC.VAR_TYPES:
self.next()
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
else:
self._readIdentifier(parent)
def _readReturnType(self, parent):
if self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _SUBROUTINEDEC.RETURN_TYPES:
self.next()
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
else:
self._readIdentifier(parent)
def _readSymbol(self, parent, expected = None):
self.next()
expectedStr = expected if expected is not None else ELEMENTS.SYMBOL
self._assertToken(self.tok, expectedStr, type_=tokenizor.SYMBOL)
if expected is not None:
self._assertToken(self.tok, expected, value_=expected)
parent.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
return self.tok.value
def _readKeyword(self, parent, expected = None):
self.next()
expectedStr = expected if expected is not None else ELEMENTS.KEYWORD
self._assertToken(self.tok, expectedStr, type_=tokenizor.KEYWORD)
if expected is not None:
self._assertToken(self.tok, expected, value_=expected)
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
return self.tok.value
def _readSymbolOptional(self, parent, expected):
if self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == expected:
self.next()
parent.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
return True
return False
def _readKeywordOptional(self, parent, expected):
if self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value == expected:
self.next()
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
return True
return False
def next(self):
self.tok = self.iter.next()
self.nextTok = self.iter.lookahead()
def _assertToken(self, tok, expected_str, type_ = None, value_ = None):
if (type_ != None and tok.type != type_) or (value_ != None and tok.value != value_):
raise self._syntaxError("Expected %s but found %s" % (expected_str, tok.value), tok)
def _syntaxError(self, msg, tok = None):
if tok is None:
tok = self.tok
return SyntaxError(msg, (None, tok.srow, tok.scol, tok.line))
def __init__(self, source, destination):
self.src = source
self.dst = destination
self.writer = VMWriter(destination)
self.iter = Lookahead(tokenizor.newTokenizor(self.src))
self._symbol_table = SymbolTable()
class CompilationEngine:
def __init__(self, source, destination):
self.src = source
self.dst = destination
self.writer = VMWriter(destination)
self.iter = Lookahead(tokenizor.newTokenizor(self.src))
self._symbol_table = SymbolTable()
def compile(self):
root = self._compileClass()
return root
def _compileClass(self):
classE = Element(ELEMENTS.CLASS)
self._readKeyword(classE, ELEMENTS.CLASS)
self.className = self._readIdentifier(classE)
self._readSymbol(classE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileClassVarDec(classE)
self._compileSubroutine(classE)
self._readSymbol(classE, _SYMBOLS.BRACKET_CURLY_CLOSE)
return classE
def _compileClassVarDec(self, parent):
while self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _CLASSVARDEC.FIELD_TYPES:
classVarDecE = Element(ELEMENTS.CLASSVARDEC)
self._readKeyword(classVarDecE)
self._readType(classVarDecE)
self._readIdentifier(classVarDecE)
while self._readSymbolOptional(classVarDecE, _SYMBOLS.COMMA):
self._readIdentifier(classVarDecE)
self._readSymbol(classVarDecE, _SYMBOLS.SEMI_COLON)
parent.append(classVarDecE)
def _compileSubroutine(self, parent):
while self.nextTok and self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _SUBROUTINEDEC.TYPES:
subroutineDecE = Element(ELEMENTS.SUBROUTINEDEC)
function_type = self._readKeyword(subroutineDecE)
self._readReturnType(subroutineDecE)
self.methodName = self._readIdentifier(subroutineDecE)
self._symbol_table.startSubroutine(self.className, self.methodName)
if function_type == _SUBROUTINEDEC.METHOD:
self._symbol_table.define("this", self.className,
SYM_KINDS.ARG)
self._uid = -1
self._readSymbol(subroutineDecE, _SYMBOLS.PARENTHESES_OPEN)
self._compileParameters(subroutineDecE)
self._readSymbol(subroutineDecE, _SYMBOLS.PARENTHESES_CLOSE)
self._compileSubroutineBody(subroutineDecE, function_type)
parent.append(subroutineDecE)
def _gen_label(self, type_):
self._uid += 1
return "%s.%s.%s.%d" % (self.className, self.methodName, type_,
self._uid)
def _gen_labels(self, *parts):
self._uid += 1
return [
"%s.%s.%s.%d" % (self.className, self.methodName, part, self._uid)
for part in parts
]
def _compileSubroutineBody(self, parent, function_type):
bodyE = Element(ELEMENTS.SUBROUTINEBODY)
self._readSymbol(bodyE, _SYMBOLS.BRACKET_CURLY_OPEN)
nArgs = self._compileVarDec(bodyE)
function_name = parent[2].text
function_full_name = "%s.%s" % (self.className, function_name)
self.writer.writeFunction(function_full_name, nArgs)
if function_type == _SUBROUTINEDEC.CONSTRUCTOR:
field_count = self._symbol_table.varCount(SYM_KINDS.FIELD)
self.writer.writePush(SEGMENT.CONST, field_count)
self.writer.writeCall("Memory.alloc", 1)
self.writer.writePop(SEGMENT.POINTER, 0)
elif function_type == _SUBROUTINEDEC.METHOD:
self.writer.writePush(SEGMENT.ARG, 0)
self.writer.writePop(SEGMENT.POINTER, 0)
self._compileStatements(bodyE)
self._readSymbol(bodyE, _SYMBOLS.BRACKET_CURLY_CLOSE)
parent.append(bodyE)
def _compileStatements(self, parent):
statementsE = Element(ELEMENTS.STATEMENTS)
while self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _STATEMENTS.TYPE_NAMES:
if self.nextTok.value == _STATEMENTS.LET:
statementE = Element(ELEMENTS.STATEMENT_LET)
self._readKeyword(statementE)
identifier = self._readIdentifier(statementE)
is_array = False
if self._readSymbolOptional(statementE, _SYMBOLS.BRACKET_OPEN):
is_array = True
self._compileExpression(statementE)
self.writer.writePush(*self._identifier_data(identifier))
self.writer.writeArithmetic("add")
self._readSymbol(statementE, _SYMBOLS.BRACKET_CLOSE)
self._readSymbol(statementE, _SYMBOLS.EQUAL)
self._compileExpression(statementE)
self._readSymbol(statementE, _SYMBOLS.SEMI_COLON)
if is_array:
self.writer.writePop(SEGMENT.TEMP, 0)
self.writer.writePop(SEGMENT.POINTER, 1)
self.writer.writePush(SEGMENT.TEMP, 0)
self.writer.writePop(SEGMENT.THAT, 0)
else:
self.writer.writePop(*self._identifier_data(identifier))
statementsE.append(statementE)
elif self.nextTok.value == _STATEMENTS.IF:
label_else, label_end = self._gen_labels("if.else", "if.end")
statementE = Element(ELEMENTS.STATEMENT_IF)
self._readKeyword(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_OPEN)
self._compileExpression(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_CLOSE)
self.writer.writeArithmetic("not")
self.writer.writeIf(label_else)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileStatements(statementE)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_CLOSE)
self.writer.writeGoto(label_end)
self.writer.writeLabel(label_else)
if self._readKeywordOptional(statementE, _KEYWORDS.ELSE):
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileStatements(statementE)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_CLOSE)
self.writer.writeLabel(label_end)
statementsE.append(statementE)
elif self.nextTok.value == _STATEMENTS.WHILE:
label_start, label_end = self._gen_labels(
"while.start", "while.end")
self.writer.writeLabel(label_start)
statementE = Element(ELEMENTS.STATEMENT_WHILE)
self._readKeyword(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_OPEN)
self._compileExpression(statementE)
self._readSymbol(statementE, _SYMBOLS.PARENTHESES_CLOSE)
self.writer.writeArithmetic("not")
self.writer.writeIf(label_end)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_OPEN)
self._compileStatements(statementE)
self._readSymbol(statementE, _SYMBOLS.BRACKET_CURLY_CLOSE)
statementsE.append(statementE)
self.writer.writeGoto(label_start)
self.writer.writeLabel(label_end)
elif self.nextTok.value == _STATEMENTS.DO:
self._compileDo(statementsE)
elif self.nextTok.value == _STATEMENTS.RETURN:
statementE = Element(ELEMENTS.STATEMENT_RETURN)
self._readKeyword(statementE)
if not (self.nextTok.type == tokenizor.SYMBOL
and self.nextTok.value == _SYMBOLS.SEMI_COLON):
self._compileExpression(statementE)
else:
self.writer.writePush(SEGMENT.CONST, 0)
self._readSymbol(statementE, _SYMBOLS.SEMI_COLON)
self.writer.writeReturn()
statementsE.append(statementE)
if len(statementsE) == 0:
statementsE.text = "\n"
parent.append(statementsE)
def _compileExpression(self, parent):
expressionE = Element(ELEMENTS.EXPRESSION)
self._readTerm(expressionE)
while self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value in _SYMBOLS.OPERATORS:
symbol = self._readSymbol(expressionE)
self._readTerm(expressionE)
self.writer.writeArithmetic(symbol)
parent.append(expressionE)
def _compileExpressionList(self, parent):
self._readSymbol(parent, _SYMBOLS.PARENTHESES_OPEN)
expListE = Element(ELEMENTS.EXPRESSION_LIST)
nArgs = 0
while not (self.nextTok.type == tokenizor.SYMBOL
and self.nextTok.value == _SYMBOLS.PARENTHESES_CLOSE):
self._compileExpression(expListE)
self._readSymbolOptional(expListE, _SYMBOLS.COMMA)
nArgs += 1
# hack for TextComparer
if len(expListE) == 0:
expListE.text = "\n"
parent.append(expListE)
self._readSymbol(parent, _SYMBOLS.PARENTHESES_CLOSE)
return nArgs
def _compileDo(self, parent):
statementE = Element(ELEMENTS.STATEMENT_DO)
self._readKeyword(statementE, _STATEMENTS.DO)
identifier = self._readIdentifier(statementE)
nArgs = 0
if self._readSymbolOptional(statementE, _SYMBOLS.DOT):
type_ = self._symbol_table.typeOf(identifier)
if type_:
segment, index = self._identifier_data(identifier)
self.writer.writePush(segment, index)
nArgs += 1
identifier = "%s.%s" % (type_,
self._readIdentifier(statementE))
else:
identifier = "%s.%s" % (identifier,
self._readIdentifier(statementE))
else:
identifier = "%s.%s" % (self.className, identifier)
self.writer.writePush(SEGMENT.POINTER, 0)
nArgs += 1
nArgs += self._compileExpressionList(statementE)
self._readSymbol(statementE, _SYMBOLS.SEMI_COLON)
self.writer.writeCall(identifier, nArgs)
self.writer.writePop(SEGMENT.TEMP, 0)
parent.append(statementE)
def _compileVarDec(self, parent):
nArgs = 0
while self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value == _KEYWORDS.VAR:
varDecE = Element(ELEMENTS.VAR_DEC)
self._readKeyword(varDecE, _KEYWORDS.VAR)
self._readType(varDecE)
self._readIdentifier(varDecE)
nArgs += 1
while self._readSymbolOptional(varDecE, _SYMBOLS.COMMA):
self._readIdentifier(varDecE)
nArgs += 1
self._readSymbol(varDecE, _SYMBOLS.SEMI_COLON)
parent.append(varDecE)
return nArgs
def _compileParameters(self, parent):
paramListE = Element(ELEMENTS.PARAM_LIST)
while (self.nextTok.type == tokenizor.KEYWORD
and self.nextTok.value in _CLASSVARDEC.VAR_TYPES
) or self.nextTok.type == tokenizor.IDENTIFIER:
self._readType(paramListE)
self._readIdentifier(paramListE)
self._readSymbolOptional(paramListE, _SYMBOLS.COMMA)
if len(paramListE) == 0:
paramListE.text = "\n"
parent.append(paramListE)
##############################
########## READ ##############
##############################
def _readTerm(self, parent):
termE = Element(ELEMENTS.TERM)
if self.nextTok.type == tokenizor.INTEGER:
self.next()
termE.append(
_leafElement(ELEMENTS.INTEGER_CONSTANT, self.tok.value))
self.writer.writePush(SEGMENT.CONST, self.tok.value)
elif self.nextTok.type == tokenizor.STRING:
self.next()
termE.append(_leafElement(ELEMENTS.STRING_CONSTANT,
self.tok.value))
string_value = self.tok.value
self.writer.writePush(SEGMENT.CONST, len(string_value))
self.writer.writeCall("String.new", 1)
for char in string_value:
self.writer.writePush(SEGMENT.CONST, ord(char))
self.writer.writeCall("String.appendChar", 2)
elif self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _KEYWORDS.CONSTANTS:
self.next()
termE.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
_KW_CONT_WRITE[self.tok.value](self.writer)
elif self.nextTok.type == tokenizor.IDENTIFIER:
identifier = self._readIdentifier(termE)
nArgs = 0
if self._readSymbolOptional(termE, _SYMBOLS.BRACKET_OPEN):
self._compileExpression(termE)
self.writer.writePush(*self._identifier_data(identifier))
self.writer.writeArithmetic("add")
self.writer.writePop(SEGMENT.POINTER, 1)
self.writer.writePush(SEGMENT.THAT, 0)
self._readSymbol(termE, _SYMBOLS.BRACKET_CLOSE)
elif self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == _SYMBOLS.PARENTHESES_OPEN:
nArgs = self._compileExpressionList(termE)
self._readSymbol(termE, _SYMBOLS.PARENTHESES_CLOSE)
self.writer.writeCall(identifier, nArgs)
elif self._readSymbolOptional(termE, _SYMBOLS.DOT):
type_ = self._symbol_table.typeOf(identifier)
if type_:
segment, index = self._identifier_data(identifier)
self.writer.writePush(segment, index)
nArgs += 1
identifier = "%s.%s" % (type_, self._readIdentifier(termE))
else:
identifier = "%s.%s" % (identifier,
self._readIdentifier(termE))
nArgs += self._compileExpressionList(termE)
self.writer.writeCall(identifier, nArgs)
else:
self.writer.writePush(*self._identifier_data(identifier))
elif self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == _SYMBOLS.PARENTHESES_OPEN:
self.next()
termE.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
self._compileExpression(termE)
self._readSymbol(termE, _SYMBOLS.PARENTHESES_CLOSE)
elif self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value in _SYMBOLS.UNARY_OPARTORS:
self.next()
sym = self.tok.value
termE.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
self._readTerm(termE)
self.writer.writeArithmeticUnary(sym)
else:
raise self._syntaxError("Unexpected %s." % self.tok.value)
parent.append(termE)
def _identifier_data(self, identifier):
return _SEG_TRANSLATE[self._symbol_table.kindOf(
identifier)], self._symbol_table.indexOf(identifier)
def _readIdentifier(self, parent):
self.next()
self._assertToken(self.tok,
ELEMENTS.IDENTIFIER,
type_=tokenizor.IDENTIFIER)
name = self.tok.value
element = _leafElement(ELEMENTS.IDENTIFIER, name)
type_ = self._symbol_table.typeOf(name)
kind = None
index = None
if type_ is None:
if parent.tag in (ELEMENTS.CLASSVARDEC,
ELEMENTS.VAR_DEC) and len(parent) > 1:
type_ = parent[1].text
kind = _SYM_KIND_MAP[parent[0].text]
elif parent.tag == ELEMENTS.PARAM_LIST and len(parent) > 0:
type_ = parent[-1].text
kind = SYM_KINDS.ARG
if kind is not None:
index = self._symbol_table.define(name, type_, kind)
else:
type_ = self._symbol_table.typeOf(name)
kind = self._symbol_table.kindOf(name)
index = self._symbol_table.indexOf(name)
if kind is not None:
element.set("type", type_)
element.set("kind", str(kind))
element.set("index", str(index))
parent.append(element)
return name
def _readType(self, parent):
if self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _CLASSVARDEC.VAR_TYPES:
self.next()
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
else:
self._readIdentifier(parent)
def _readReturnType(self, parent):
if self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value in _SUBROUTINEDEC.RETURN_TYPES:
self.next()
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
else:
self._readIdentifier(parent)
def _readSymbol(self, parent, expected=None):
self.next()
expectedStr = expected if expected is not None else ELEMENTS.SYMBOL
self._assertToken(self.tok, expectedStr, type_=tokenizor.SYMBOL)
if expected is not None:
self._assertToken(self.tok, expected, value_=expected)
parent.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
return self.tok.value
def _readKeyword(self, parent, expected=None):
self.next()
expectedStr = expected if expected is not None else ELEMENTS.KEYWORD
self._assertToken(self.tok, expectedStr, type_=tokenizor.KEYWORD)
if expected is not None:
self._assertToken(self.tok, expected, value_=expected)
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
return self.tok.value
def _readSymbolOptional(self, parent, expected):
if self.nextTok.type == tokenizor.SYMBOL and self.nextTok.value == expected:
self.next()
parent.append(_leafElement(ELEMENTS.SYMBOL, self.tok.value))
return True
return False
def _readKeywordOptional(self, parent, expected):
if self.nextTok.type == tokenizor.KEYWORD and self.nextTok.value == expected:
self.next()
parent.append(_leafElement(ELEMENTS.KEYWORD, self.tok.value))
return True
return False
def next(self):
self.tok = self.iter.next()
self.nextTok = self.iter.lookahead()
def _assertToken(self, tok, expected_str, type_=None, value_=None):
if (type_ != None and tok.type != type_) or (value_ != None
and tok.value != value_):
raise self._syntaxError(
"Expected %s but found %s" % (expected_str, tok.value), tok)
def _syntaxError(self, msg, tok=None):
if tok is None:
tok = self.tok
return SyntaxError(msg, (None, tok.srow, tok.scol, tok.line))
class CompilationEngine:
def __init__(self, token_stream, out_file, xml_name):
'''
creates a new compilation engine with the given input and output.
The next method called must be compileClass().
'''
self.stream = token_stream
self.writer = VMWriter(out_file)
self.symbols = SymbolTable()
self.xml_name = xml_name
self.root = ET.Element('class')
self.stream.advance()
assert self.stream.keyword() == 'class'
def add_terminal(self, root, text):
terminal = ET.SubElement(root, self.stream.token_type())
terminal.text = ' {text} '.format(text=text)
if self.stream.has_more_tokens():
self.stream.advance()
def compile_class(self):
'''
compiles a complete class
'''
self.add_terminal(self.root, self.stream.keyword())
self.class_name = self.stream.identifier()
self.add_terminal(self.root, self.class_name)
self.add_terminal(self.root, self.stream.symbol())
while self.stream.token_type() == tokenizer.KEYWORD and self.stream.keyword() in CLASS_VARS:
self.compile_class_var_dec()
while self.stream.token_type() == tokenizer.KEYWORD and self.stream.keyword() in SUBROUTINE_TYPES:
self.compile_subroutine()
self.add_terminal(self.root, self.stream.symbol())
def compile_class_var_dec(self):
'''
compiles a static declaration or a field declaration.
'''
class_var_root = ET.SubElement(self.root, CLASS_VAR_DEC)
kind = self.stream.keyword()
self.add_terminal(class_var_root, kind)
if self.stream.token_type() == tokenizer.KEYWORD:
type_name = self.stream.keyword()
else:
type_name = self.stream.identifier()
self.add_terminal(class_var_root, type_name)
name = self.stream.identifier()
self.add_terminal(class_var_root, name)
self.symbols.define(name, type_name, kind)
while self.stream.symbol() == COMMA:
self.add_terminal(class_var_root, self.stream.symbol())
name = self.stream.identifier()
self.add_terminal(class_var_root, name)
self.symbols.define(name, type_name, kind)
self.add_terminal(class_var_root, self.stream.symbol())
def compile_subroutine(self):
'''
compiles a complete method, function, or constructor.
'''
subroutine_dec = ET.SubElement(self.root, SUBROUTINE_DEC)
self.symbols.start_subroutine()
subroutine_type = self.stream.keyword()
if subroutine_type in ['method', 'constructor']:
self.symbols.define('this', self.class_name, 'argument')
self.add_terminal(subroutine_dec, subroutine_type)
if self.stream.token_type() == tokenizer.KEYWORD:
self.add_terminal(subroutine_dec, self.stream.keyword())
else:
self.add_terminal(subroutine_dec, self.stream.identifier())
name = self.stream.identifier()
self.add_terminal(subroutine_dec, name)
self.add_terminal(subroutine_dec, self.stream.symbol())
self.compile_parameter_list(subroutine_dec)
self.add_terminal(subroutine_dec, self.stream.symbol())
subroutine_body = ET.SubElement(subroutine_dec, SUBROUTINE_BODY)
self.add_terminal(subroutine_body, self.stream.symbol())
while self.stream.token_type() == tokenizer.KEYWORD and self.stream.keyword() == VAR:
self.compile_var_dec(subroutine_body)
func_name = '{cls}.{sub}'.format(
cls=self.class_name,
sub=name)
self.writer.write_function(func_name, self.symbols.var_count('var'))
self.compile_statements(subroutine_body)
self.add_terminal(subroutine_body, self.stream.symbol())
def compile_parameter_list(self, root):
'''
compiles a (possibly empty) parameter list, not including the enclosing “()”.
'''
parameter_list_root = ET.SubElement(root, PARAMETER_LIST)
if self.stream.token_type() != tokenizer.SYMBOL:
type_name = self.stream.keyword()
self.add_terminal(parameter_list_root, type_name)
name = self.stream.identifier()
self.add_terminal(parameter_list_root, name)
self.symbols.define(name, type_name, 'argument')
while self.stream.token_type() == tokenizer.SYMBOL and self.stream.symbol() == COMMA:
self.add_terminal(parameter_list_root, self.stream.symbol())
type_name = self.stream.keyword()
self.add_terminal(parameter_list_root, type_name)
name = self.stream.identifier()
self.add_terminal(parameter_list_root, name)
self.symbols.define(name, type_name, 'argument')
def compile_var_dec(self, root):
'''
compiles a var declaration
'''
var_dec_root = ET.SubElement(root, VAR_DEC)
self.add_terminal(var_dec_root, self.stream.keyword())
type_name = None
if self.stream.token_type() == tokenizer.IDENTIFIER:
type_name = self.stream.identifier()
else:
type_name = self.stream.keyword()
self.add_terminal(var_dec_root, type_name)
name = self.stream.identifier()
self.add_terminal(var_dec_root, name)
self.symbols.define(name, type_name, 'var')
while self.stream.symbol() == COMMA:
self.add_terminal(var_dec_root, self.stream.symbol())
name = self.stream.identifier()
self.add_terminal(var_dec_root, name)
self.symbols.define(name, type_name, 'var')
self.add_terminal(var_dec_root, self.stream.symbol())
def compile_statements(self, root):
'''
compiles a sequence of statements, not including the enclosing “{}”.
'''
statements_root = ET.SubElement(root, STATEMENTS)
while self.stream.token_type() == tokenizer.KEYWORD:
keyword = self.stream.keyword()
if keyword == 'let':
self.compile_let(statements_root)
elif keyword == 'if':
self.compile_if(statements_root)
elif keyword == 'while':
self.compile_while(statements_root)
elif keyword == 'do':
self.compile_do(statements_root)
elif keyword == 'return':
self.compile_return(statements_root)
else:
assert False, 'unsupported keyword {keyword}'.format(keyword=keyword)
def compile_do(self, root):
'''
compiles a do statement
'''
do_root = ET.SubElement(root, DO)
self.add_terminal(do_root, self.stream.keyword())
self.compile_subroutine_call(do_root)
self.writer.write_pop('temp', 0)
self.add_terminal(do_root, self.stream.symbol())
def compile_let(self, root):
'''
compiles a let statement
'''
let_root = ET.SubElement(root, LET)
self.add_terminal(let_root, self.stream.keyword())
lhs = self.stream.identifier()
self.add_terminal(let_root, lhs)
if self.stream.token_type() == tokenizer.SYMBOL and self.stream.symbol() == OPEN_BRACKET:
self.add_terminal(let_root, self.stream.symbol())
self.compile_expression(let_root)
self.add_terminal(let_root, self.stream.symbol())
self.add_terminal(let_root, self.stream.symbol())
self.compile_expression(let_root)
self.add_terminal(let_root, self.stream.symbol())
self.writer.write_pop(self.symbols.kind_of(lhs), self.symbols.index_of(lhs))
def compile_while(self, root):
'''
compiles a while statement
'''
while_root = ET.SubElement(root, WHILE)
while_expression = self.symbols.generate_label('WHILE_EXP')
while_end = self.symbols.generate_label('WHILE_END')
self.add_terminal(while_root, self.stream.keyword())
self.add_terminal(while_root, self.stream.symbol())
self.writer.write_label(while_expression)
self.compile_expression(while_root)
self.writer.write_arithmetic('not')
self.writer.write_if(while_end)
self.add_terminal(while_root, self.stream.symbol())
self.add_terminal(while_root, self.stream.symbol())
self.compile_statements(while_root)
self.writer.write_goto(while_expression)
self.writer.write_label(while_end)
self.add_terminal(while_root, self.stream.symbol())
def compile_return(self, root):
'''
compiles a return statement
'''
return_root = ET.SubElement(root, RETURN)
self.add_terminal(return_root, self.stream.keyword())
if self.stream.token_type() != tokenizer.SYMBOL:
self.compile_expression(return_root)
else:
self.writer.write_push('constant', 0)
self.writer.write_return()
self.add_terminal(return_root, self.stream.symbol())
def compile_if(self, root):
'''
compiles an if statement
'''
if_root = ET.SubElement(root, IF)
if_label = self.symbols.generate_label('IF_TRUE')
else_label = self.symbols.generate_label('IF_FALSE')
end_label = self.symbols.generate_label('IF_END')
self.add_terminal(if_root, self.stream.keyword())
self.add_terminal(if_root, self.stream.symbol())
self.compile_expression(if_root)
self.writer.write_if(if_label)
self.writer.write_goto(else_label)
self.writer.write_label(if_label)
self.add_terminal(if_root, self.stream.symbol())
self.add_terminal(if_root, self.stream.symbol())
self.compile_statements(if_root)
self.writer.write_goto(end_label)
self.add_terminal(if_root, self.stream.symbol())
self.writer.write_label(else_label)
if self.stream.token_type() == tokenizer.KEYWORD and self.stream.keyword() == 'else':
self.add_terminal(if_root, self.stream.keyword())
self.add_terminal(if_root, self.stream.symbol())
self.compile_statements(if_root)
self.add_terminal(if_root, self.stream.symbol())
self.writer.write_label(end_label)
def compile_expression(self, root):
'''
compiles an expression
'''
expression_root = ET.SubElement(root, EXPRESSION)
self.compile_term(expression_root)
while self.stream.token_type() == tokenizer.SYMBOL and self.stream.symbol() in OPS:
operator = self.stream.symbol()
self.add_terminal(expression_root, operator)
self.compile_term(expression_root)
if operator == '+':
self.writer.write_arithmetic('add'),
if operator == '-':
self.writer.write_arithmetic('sub'),
if operator == '*':
self.writer.write_call('Math.multiply', 2),
if operator == '/':
self.writer.write_call('Math.divide', 2),
if operator == '&':
self.writer.write_arithmetic('and'),
if operator == '|':
self.writer.write_arithmetic('or'),
if operator == '<':
self.writer.write_arithmetic('lt'),
if operator == '>':
self.writer.write_arithmetic('gt'),
if operator == '=':
self.writer.write_arithmetic('eq')
def compile_term(self, root):
'''
compiles a term. This method is faced with a slight difficulty when trying to
decide between some of the alternative rules. Specifically, if the current token
is an identifier, it must still distinguish between a variable, an array entry, and
a subroutine call. The distinction can be made by looking ahead one extra token.
A single look-ahead token, which may be one of “[“, “(“, “.”, suffices to
distinguish between the three possibilities. Any other token is not
part of this term and should not be advanced over.
'''
term_root = ET.SubElement(root, TERM)
token_type = self.stream.token_type()
if token_type == tokenizer.INT:
val = self.stream.int_val()
self.add_terminal(term_root, val)
self.writer.write_push('constant', val)
elif token_type == tokenizer.STRING:
val = self.stream.string_val()
self.add_terminal(term_root, val)
#TODO I think it's a character by character push, ugh
self.writer.write_push('constant', val)
elif token_type == tokenizer.KEYWORD and self.stream.keyword() in KEYWORD_CONSTANTS:
keyword = self.stream.keyword()
self.add_terminal(term_root, keyword)
if keyword == 'true':
self.writer.write_push('constant', 0)
self.writer.write_arithmetic('not')
elif keyword in ['false', 'null']:
self.writer.write_push('constant', 0)
else:
self.writer.write_push('this', 0)
elif token_type == tokenizer.IDENTIFIER:
if self.stream.peek() == OPEN_BRACKET:
name = self.stream.identifier()
self.writer.write_push(self.symbols.kind_of(name), self.symbols.index_of(name))
self.add_terminal(term_root, name)
self.add_terminal(term_root, self.stream.symbol())
self.compile_expression(term_root)
self.add_terminal(term_root, self.stream.symbol())
elif self.stream.peek() == OPEN_PAREN or self.stream.peek() == PERIOD:
self.compile_subroutine_call(term_root)
else:
name = self.stream.identifier()
self.add_terminal(term_root, self.stream.identifier())
self.writer.write_push(self.symbols.kind_of(name), self.symbols.index_of(name))
elif token_type == tokenizer.SYMBOL and self.stream.symbol() == OPEN_PAREN:
self.add_terminal(term_root, self.stream.symbol())
self.compile_expression(term_root)
self.add_terminal(term_root, self.stream.symbol())
elif token_type == tokenizer.SYMBOL and self.stream.symbol() in UNARY_OPS:
operator = self.stream.symbol()
self.add_terminal(term_root, operator)
self.compile_term(term_root)
self.writer.write_arithmetic('neg' if operator == '-' else 'not')
else:
assert False, 'unsupported token {token}'.format(token=self.stream.current_token)
def compile_expression_list(self, root):
'''
compiles a (possibly empty) comma-separated list of expressions.
'''
expression_list_root = ET.SubElement(root, EXPRESSION_LIST)
if self.stream.token_type() == tokenizer.SYMBOL and self.stream.symbol() == CLOSE_PAREN:
return 0
self.compile_expression(expression_list_root)
num_vars = 1
while self.stream.symbol() == COMMA:
self.add_terminal(expression_list_root, self.stream.symbol())
self.compile_expression(expression_list_root)
num_vars += 1
return num_vars
def compile_subroutine_call(self, root):
class_name = self.class_name
subroutine_name = self.stream.identifier()
self.add_terminal(root, class_name)
if self.stream.symbol() == PERIOD:
self.add_terminal(root, self.stream.symbol())
class_name = subroutine_name
subroutine_name = self.stream.identifier()
self.add_terminal(root, self.stream.identifier())
self.add_terminal(root, self.stream.symbol())
num_vars = self.compile_expression_list(root)
self.add_terminal(root, self.stream.symbol())
self.writer.write_call('{cls}.{sub}'.format(
cls=class_name,
sub=subroutine_name),
num_vars)
def write(self):
if self.xml_name:
lines = self._write(self.root).split('\n')
lines = lines[1:]
file = open(self.xml_name, 'w')
file.write('\n'.join(lines))
file.close()
self.writer.close()
def _write(self, root):
return minidom.parseString(ET.tostring(root)).toprettyxml()
def build_vm_writer(self, jack_file):
self.vm_writer = VMWriter(jack_file)
class CompilationEngine:
'''The brain of the Jack syntax analyzer'''
# Constructor
def __init__(self, tokenizer: JackTokenizer, out_path: Path):
self.tokenizer = tokenizer
# Create symbol tables
self.class_level_st = SymbolTable()
self.subroutine_level_st = SymbolTable()
# class's name
self.class_name = None
self.func_name = None
self.sub_type = None
# Open the output file for writing
self.out_stream = out_path.open('w')
# Create a new VM writer for writing
self.vm_writer = VMWriter(out_path.with_suffix(".vm"))
# For generating labels
self.label_count = {"if": 0, "while": 0}
def get_if_labels(self):
self.label_count["if"] += 1
return (f"LABEL_IF_{self.label_count['if'] - 1}_1",
f"LABEL_IF_{self.label_count['if'] - 1}_2")
def get_while_labels(self):
self.label_count["while"] += 1
return (f"LABEL_WHILE_{self.label_count['while'] - 1}_1",
f"LABEL_WHILE_{self.label_count['while'] - 1}_2")
def start_compilation(self):
# Read the first token into memory
self.tokenizer.has_more_tokens()
# Start analyzing syntax
if self.tokenizer.get_token_type() == TokenType.KEYWORD:
if self.tokenizer.get_keyword_type() == KeywordType.CLASS:
self.compile_class()
else:
raise AttributeError("Not starting with a class")
# Helper method to write terminal XML tags
def write_terminal_tag(self, t, v):
if t == TokenType.KEYWORD:
self.out_stream.write(f"<keyword> {v} </keyword>\n")
elif t == TokenType.IDENTIFIER:
self.out_stream.write(f"<identifier> {v} </identifier>\n")
elif t == TokenType.SYMBOL:
self.out_stream.write(f"<symbol> {v} </symbol>\n")
elif t == TokenType.INT_CONST:
self.out_stream.write(
f"<integerConstant> {v} </integerConstant>\n")
elif t == TokenType.STRING_CONST:
self.out_stream.write(f"<stringConstant> {v} </stringConstant>\n")
# 'class' className '{' classVarDec* subroutineDec* '}'
def compile_class(self):
# Write opening tag
self.out_stream.write("<class>\n")
self.write_terminal_tag(self.tokenizer.get_token_type(), 'class')
# Read the next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
self.class_name = self.tokenizer.get_cur_ident()
self.write_terminal_tag(self.tokenizer.get_token_type(),
self.class_name)
self.out_stream.write("\n===DECLARED===\nclass name\n=======")
else:
raise AttributeError("Not a valid class name!")
# Read the next token
self.tokenizer.has_more_tokens()
self.eat('{')
self.write_terminal_tag(self.tokenizer.get_token_type(),
self.tokenizer.get_symbol())
# Handle class variable declaration (classVarDec*)
# Proceed to next token
self.tokenizer.has_more_tokens()
# While there are field/static declarations
while \
(self.tokenizer.get_token_type() == TokenType.KEYWORD) and\
(
self.tokenizer.get_keyword_type() in (KeywordType.FIELD, KeywordType.STATIC)
):
self.compile_class_var_dec()
while \
(self.tokenizer.get_token_type() == TokenType.KEYWORD) and\
(
self.tokenizer.get_keyword_type() in (KeywordType.CONSTRUCTOR, KeywordType.FUNCTION, KeywordType.METHOD)
):
self.compile_subroutine_dec()
# Class ending curly brackets
self.eat("}")
self.write_terminal_tag(TokenType.SYMBOL, "}")
# At the end of function call
self.out_stream.write("</class>\n")
# ('static'|'field') type varName (',' varName)* ';'
def compile_class_var_dec(self):
# Write opening tag
self.out_stream.write("<classVarDec>\n")
# Write static/field
self.write_terminal_tag(TokenType.KEYWORD,
self.tokenizer.get_cur_ident())
# To store variable properties
var_kind = None
var_type = None
var_index = None
var_name = None
if self.tokenizer.get_cur_ident() == "static":
var_kind = SymbolKind.STATIC
elif self.tokenizer.get_cur_ident() == "field":
var_kind = SymbolKind.FEILD
else:
raise Exception("Other than static or feild:" +
self.tokenizer.get_cur_ident())
# Read the next token
self.tokenizer.has_more_tokens()
if self.is_valid_type():
self.write_terminal_tag(self.tokenizer.get_token_type(),
self.tokenizer.get_cur_ident())
var_type = self.tokenizer.get_cur_ident()
else:
raise AssertionError("Invalid class variable type!")
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
# Write varible tag to XML file
self.write_terminal_tag(self.tokenizer.get_token_type(), var_name)
# Define new class level variable
self.class_level_st.define(var_name, var_type, var_kind)
var_index = self.class_level_st.get_index_of(var_name)
# Write variable properties
self.out_stream.write(
f"\n===DECLARED===\nkind: {var_kind}, type: {var_type}, index: {var_index}\n======="
)
else:
raise AssertionError("Invalid class variable name!")
# Move to the next token
self.tokenizer.has_more_tokens()
# If has more than one varibles: E.g. field int x, y, z;
while self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == ",":
self.write_terminal_tag(TokenType.SYMBOL, ",")
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
# Write varible tag to XML file
self.write_terminal_tag(self.tokenizer.get_token_type(),
var_name)
# Define new class level variable
self.class_level_st.define(var_name, var_type, var_kind)
var_index = self.class_level_st.get_index_of(var_name)
# Write variable properties
self.out_stream.write(
f"\n===DECLARED===\nkind: {var_kind}, type: {var_type}, index: {var_index}\n======="
)
else:
raise AssertionError(
"Invalid Syntax for class varible declaration!")
# Move to next token
self.tokenizer.has_more_tokens()
# Must end with ";"
self.eat(";")
self.write_terminal_tag(TokenType.SYMBOL, ";")
# Move to next token
self.tokenizer.has_more_tokens()
# Write closing tag
self.out_stream.write("</classVarDec>\n")
# ('constructor' | 'function' | 'method') ('void' | 'type') subroutineName
def compile_subroutine_dec(self):
# Opening tag
self.out_stream.write("<subroutineDec>\n")
# To store function parameters
func_params = {}
# Write subroutine type
self.sub_type = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.KEYWORD, self.sub_type)
# Reset subroutine level symbol table
self.subroutine_level_st.reset_table()
# Insert `this`, if method
if self.sub_type == "method":
self.subroutine_level_st.define("this", self.class_name,
SymbolKind.ARG)
# Move to next token
self.tokenizer.has_more_tokens()
if self.is_valid_type() or \
(self.tokenizer.get_token_type() == TokenType.KEYWORD \
and self.tokenizer.get_keyword_type() == KeywordType.VOID):
self.write_terminal_tag(self.tokenizer.get_token_type(),
self.tokenizer.get_cur_ident())
else:
raise AssertionError("Not a valid subroutine return type!")
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
func_params["name"] = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, func_params["name"])
else:
raise AssertionError("Invalid Syntax for function name!")
# Move to next token
self.tokenizer.has_more_tokens()
self.eat('(')
self.write_terminal_tag(TokenType.SYMBOL, "(")
# Move to next token
self.tokenizer.has_more_tokens()
# If there are some parameters
self.out_stream.write("<parameterList>\n")
if not (self.tokenizer.get_token_type() == TokenType.SYMBOL):
self.compile_parameter_list()
self.out_stream.write("</parameterList>\n")
# Move to next token
self.eat(')')
self.write_terminal_tag(TokenType.SYMBOL, ")")
# Write function VM command
self.func_name = func_params['name']
# Move to the next token
self.tokenizer.has_more_tokens()
self.compile_subroutine_body()
# Closing tag
self.out_stream.write("</subroutineDec>\n")
# ((type varName) (',' type varName)*)?
def compile_parameter_list(self):
# For storing varible params
var_name = None
var_type = None
var_kind = SymbolKind.ARG # Argument list
var_index = None
if self.is_valid_type():
var_type = self.tokenizer.get_cur_ident()
self.write_terminal_tag(self.tokenizer.get_token_type(), var_type)
else:
raise AssertionError("Invalid syntax in parameter list!")
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, var_name)
else:
raise AssertionError(
"Invalid Syntax for function parameter name name!")
# Define the argument variable
self.subroutine_level_st.define(var_name, var_type, var_kind)
# Get the index of the newly created variable
var_index = self.subroutine_level_st.get_index_of(var_name)
# Write variable properties
self.out_stream.write(
f"\n===DECLARED===\nkind: {var_kind}, type: {var_type}, index: {var_index}\n======="
)
# Move to next token
self.tokenizer.has_more_tokens()
# Handle more than one parameters
while self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == ",":
self.write_terminal_tag(TokenType.SYMBOL, ",")
# Read the next token
self.tokenizer.has_more_tokens()
# If the current token is a valid type name
if self.is_valid_type():
var_type = self.tokenizer.get_cur_ident()
self.write_terminal_tag(self.tokenizer.get_token_type(),
var_type)
else:
raise AssertionError("Invalid variable type in parameter list")
# Read the next token
self.tokenizer.has_more_tokens()
# If current token is a valid identifier
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, var_name)
else:
raise AssertionError(
"Invalid variable name in parameter list!!")
self.subroutine_level_st.define(var_name, var_type, var_kind)
var_index = self.subroutine_level_st.get_index_of(var_name)
# Write variable properties
self.out_stream.write(
f"\n===DECLARED===\nkind: {var_kind}, type: {var_type}, index: {var_index}\n======="
)
# Read the next token
self.tokenizer.has_more_tokens()
# '{' varDec* statements '}'
def compile_subroutine_body(self):
# Write opening tag
self.out_stream.write("<subroutineBody>\n")
# Eat opening curly bracket
self.eat("{")
self.write_terminal_tag(TokenType.SYMBOL, "{")
# Move to next token
self.tokenizer.has_more_tokens()
# Handle variable declarations
while self.tokenizer.get_token_type() == TokenType.KEYWORD \
and self.tokenizer.get_keyword_type() == KeywordType.VAR:
# Current token is the 'var' keyword
self.compile_var_dec()
# Get number of local variables
# for the current compiling function
nVars = self.subroutine_level_st.get_var_count(SymbolKind.VAR)
# Write function
self.vm_writer.write_function(f"{self.class_name}.{self.func_name}",
nVars)
if self.sub_type == "constructor":
nFeilds = self.class_level_st.get_var_count(SymbolKind.FEILD)
# write "push constant nFeilds"
self.vm_writer.write_push(SegmentType.CONST, nFeilds)
self.vm_writer.write_call("Memory.alloc", 1)
self.vm_writer.write_pop(SegmentType.POINTER, 0)
elif self.sub_type == "method":
# push argument 0
self.vm_writer.write_push(SegmentType.ARG, 0)
# pop pointer 0
self.vm_writer.write_pop(SegmentType.POINTER, 0)
# Handle statements
self.compile_statements()
# Eat closing curly bracker
self.eat("}")
self.write_terminal_tag(TokenType.SYMBOL, "}")
# Move to next token
self.tokenizer.has_more_tokens()
# Write closing tag
self.out_stream.write("</subroutineBody>\n")
# 'var' type varName (',' varName)* ';'
def compile_var_dec(self):
# Write opening tag
self.out_stream.write("<varDec>\n")
# Write var keyword tag
self.write_terminal_tag(TokenType.KEYWORD, "var")
# For storing variable params
var_name = None
var_type = None
var_kind = SymbolKind.VAR
var_index = None
# Move to next token
self.tokenizer.has_more_tokens()
# Write the type of variables
if self.is_valid_type():
var_type = self.tokenizer.get_cur_ident()
self.write_terminal_tag(self.tokenizer.get_token_type(), var_type)
else:
raise AssertionError("Not a valid var type!")
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, var_name)
else:
raise AssertionError("Invalid Syntax for var name!")
# Move to next token
self.tokenizer.has_more_tokens()
self.subroutine_level_st.define(var_name, var_type, var_kind)
var_index = self.subroutine_level_st.get_index_of(var_name)
# Write variable properties
self.out_stream.write(
f"\n===DECLARED===\nkind: {var_kind}, type: {var_type}, index: {var_index}\n======="
)
while self.tokenizer.get_token_type(
) == TokenType.SYMBOL and self.tokenizer.get_symbol() == ",":
# Write this symbol
self.write_terminal_tag(TokenType.SYMBOL, ",")
# Move to the next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, var_name)
else:
raise AssertionError("Invalid Syntax for var name!")
self.subroutine_level_st.define(var_name, var_type, var_kind)
var_index = self.subroutine_level_st.get_index_of(var_name)
# Write variable properties
self.out_stream.write(
f"\n===DECLARED===\nkind: {var_kind}, type: {var_type}, index: {var_index}\n======="
)
# Move to the next token
self.tokenizer.has_more_tokens()
self.eat(";")
self.write_terminal_tag(TokenType.SYMBOL, ";")
# Move to the next token
self.tokenizer.has_more_tokens()
# Write closing tag
self.out_stream.write("</varDec>\n")
# statement*
def compile_statements(self):
# Write open tag
self.out_stream.write("<statements>\n")
# Process statements
while self.tokenizer.get_token_type(
) == TokenType.KEYWORD and self.tokenizer.get_keyword_type(
) in statement_types:
# Statment type is based on the starting keyword
statement_type = self.tokenizer.get_keyword_type()
# Call compile method based on type
if statement_type == KeywordType.LET:
self.compile_let()
elif statement_type == KeywordType.IF:
self.compile_if()
elif statement_type == KeywordType.WHILE:
self.compile_while_statement()
elif statement_type == KeywordType.DO:
self.compile_do()
elif statement_type == KeywordType.RETURN:
self.compile_return()
self.out_stream.write("</statements>\n")
# 'let' varName ('[' expression ']')? '=' expression ';'
def compile_let(self):
self.out_stream.write("<letStatement>\n")
self.write_terminal_tag(TokenType.KEYWORD, "let")
# Is Array?
is_array_access = False
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
var_name = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, var_name)
var_props = self.lookup_st(var_name)
# Write variable properties
self.out_stream.write(
f"\n===USED===\nkind: {var_props['kind']}, type: {var_props['type']}, index: {var_props['index']}\n======="
)
# Finding segment type
var_props["seg_type"] = self.var_t_to_segment_t(var_props["kind"])
else:
raise AssertionError("Invalid Syntax for varName!")
# Move to next token
self.tokenizer.has_more_tokens()
# Optional bracket syntax
if self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == "[":
is_array_access = True
# push arr
self.vm_writer.write_push(
self.var_t_to_segment_t(var_props["kind"]), var_props["index"])
self.write_terminal_tag(TokenType.SYMBOL, "[")
# Move to next token
self.tokenizer.has_more_tokens()
# Compile the expression
self.compile_expression()
self.eat("]")
self.write_terminal_tag(TokenType.SYMBOL, "]")
# add
self.vm_writer.write_arithmetic(ArithmeticCType.ADD)
# Move to the next token
self.tokenizer.has_more_tokens()
# Eat assignment operator
self.eat("=")
self.write_terminal_tag(TokenType.SYMBOL, "=")
# Move to next token
self.tokenizer.has_more_tokens()
self.compile_expression()
self.eat(";")
self.write_terminal_tag(TokenType.SYMBOL, ";")
# Move to next token
self.tokenizer.has_more_tokens()
if not is_array_access:
self.vm_writer.write_pop(var_props["seg_type"], var_props["index"])
else:
# pop temp 0
self.vm_writer.write_pop(SegmentType.TEMP, 0)
# pop pointer 1
self.vm_writer.write_pop(SegmentType.POINTER, 1)
# push temp 0
self.vm_writer.write_push(SegmentType.TEMP, 0)
# pop that 0
self.vm_writer.write_pop(SegmentType.THAT, 0)
self.out_stream.write("</letStatement>\n")
# 'if' '(' expression ')' '{' statements '}' ('else' '{' statements '}')?
def compile_if(self):
self.out_stream.write("<ifStatement>\n")
self.vm_writer.write_comment("if statement")
self.write_terminal_tag(TokenType.KEYWORD, "if")
# get the next labels
L1, L2 = self.get_if_labels()
# Move to next token
self.tokenizer.has_more_tokens()
self.eat("(")
self.write_terminal_tag(TokenType.SYMBOL, "(")
# Move to next token
self.tokenizer.has_more_tokens()
# write code for the expression
self.compile_expression()
self.eat(")")
self.write_terminal_tag(TokenType.SYMBOL, ")")
# Move to next token
self.tokenizer.has_more_tokens()
# not, the condition inside if
self.vm_writer.write_arithmetic(ArithmeticCType.NOT)
self.vm_writer.write_if(L1)
self.eat("{")
self.write_terminal_tag(TokenType.SYMBOL, "{")
# Move to next token
self.tokenizer.has_more_tokens()
# Compile if-block body
self.compile_statements()
self.vm_writer.write_goto(L2)
self.vm_writer.write_label(L1)
self.eat("}")
self.write_terminal_tag(TokenType.SYMBOL, "}")
# Move to next token
self.tokenizer.has_more_tokens()
# If there is an else statement
# Handle else block
if self.tokenizer.get_token_type() == TokenType.KEYWORD \
and self.tokenizer.get_keyword_type() == KeywordType.ELSE:
self.write_terminal_tag(TokenType.KEYWORD, "else")
# Move to next token
self.tokenizer.has_more_tokens()
self.eat("{")
self.write_terminal_tag(TokenType.SYMBOL, "{")
# Move to next token
self.tokenizer.has_more_tokens()
self.compile_statements()
self.eat("}")
self.write_terminal_tag(TokenType.SYMBOL, "}")
# Move to next token
self.tokenizer.has_more_tokens()
self.vm_writer.write_label(L2)
# Write closing tag
self.out_stream.write("</ifStatement>\n")
# 'while' '(' expression ')' '{' statements '}'
def compile_while_statement(self):
self.out_stream.write("<whileStatement>\n")
self.write_terminal_tag(TokenType.KEYWORD, "while")
L1, L2 = self.get_while_labels()
self.vm_writer.write_label(L1)
# Move to next token
self.tokenizer.has_more_tokens()
self.eat("(")
self.write_terminal_tag(TokenType.SYMBOL, "(")
# Move to next token
self.tokenizer.has_more_tokens()
self.compile_expression()
self.eat(")")
self.write_terminal_tag(TokenType.SYMBOL, ")")
self.vm_writer.write_arithmetic(ArithmeticCType.NOT)
self.vm_writer.write_if(L2)
# Move to next token
self.tokenizer.has_more_tokens()
self.eat("{")
self.write_terminal_tag(TokenType.SYMBOL, "{")
# Move to next token
self.tokenizer.has_more_tokens()
# Compile block body
self.compile_statements()
self.eat("}")
self.write_terminal_tag(TokenType.SYMBOL, "}")
# Move to next token
self.tokenizer.has_more_tokens()
self.vm_writer.write_goto(L1)
self.vm_writer.write_label(L2)
# Write closing tag
self.out_stream.write("</whileStatement>\n")
# 'do' subroutineCall ';'
def compile_do(self):
# To store first and second parts of subroutine call
first_part, second_part = None, None
# To store nArgs passed to the subroutine
nArgs = 0
# Write opening tag
self.out_stream.write("<doStatement>\n")
# Write do keyword tag
self.write_terminal_tag(TokenType.KEYWORD, "do")
# Move to next token
self.tokenizer.has_more_tokens()
# Handle subroutineCall
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
first_part = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, first_part)
else:
raise AssertionError("Not a valid subroutine/class name!!!")
var_props = self.lookup_st(first_part)
if var_props:
self.vm_writer.write_push(
self.var_t_to_segment_t(var_props["kind"]), var_props["index"])
# Move to next token
self.tokenizer.has_more_tokens()
# Is is a method call
if self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == ".":
self.write_terminal_tag(TokenType.SYMBOL, ".")
# Move to next token
self.tokenizer.has_more_tokens()
# Handle subroutineCall
if self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
second_part = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER, second_part)
else:
raise AssertionError("Not a valid subroutine/class name!!!")
# Move to next token
self.tokenizer.has_more_tokens()
self.eat("(")
self.write_terminal_tag(TokenType.SYMBOL, "(")
# Move to next token
self.tokenizer.has_more_tokens()
self.out_stream.write("<expressionList>\n")
if not (self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == ")"):
nArgs = self.compile_expression_list()
self.out_stream.write("</expressionList>\n")
self.eat(")")
self.write_terminal_tag(TokenType.SYMBOL, ")")
# Move to next token
self.tokenizer.has_more_tokens()
self.eat(";")
self.write_terminal_tag(TokenType.SYMBOL, ";")
# Move to next token
self.tokenizer.has_more_tokens()
if var_props:
if second_part:
self.vm_writer.write_call(f"{var_props['type']}.{second_part}",
nArgs + 1)
else:
# Write method call
if second_part:
# Of some other class
self.vm_writer.write_call(f"{first_part}.{second_part}", nArgs)
else:
# Of this class
self.vm_writer.write_call(f"{self.class_name}.{first_part}",
nArgs)
# call-and-return contract
self.vm_writer.write_pop(SegmentType.TEMP, 0)
# Write closing tag
self.out_stream.write("</doStatement>\n")
# 'return' expression? ';'
def compile_return(self):
# Write opening tag
self.out_stream.write("<returnStatement>\n")
# Write do keyword tag
self.write_terminal_tag(TokenType.KEYWORD, "return")
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == ";":
self.write_terminal_tag(TokenType.SYMBOL, ";")
# the subroutine void return type
self.vm_writer.write_push(SegmentType.CONST, 0)
else:
self.compile_expression()
self.eat(";")
self.write_terminal_tag(TokenType.SYMBOL, ";")
# Move to next token
self.tokenizer.has_more_tokens()
# Write return command
self.vm_writer.write_return()
# Write closing tag
self.out_stream.write("</returnStatement>\n")
# term (op term)*
def compile_expression(self):
self.out_stream.write("<expression>\n")
# Compile term
self.compile_term()
# Handle (op term)*
while self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() in allowed_op:
symbol = self.tokenizer.get_symbol()
# Write tag for operation symbol
self.write_terminal_tag(TokenType.SYMBOL,
self.tokenizer.get_symbol())
# Move to next token
self.tokenizer.has_more_tokens()
# Compile term
self.compile_term()
# Apply operation
self.vm_writer.write_arithmetic(allowed_op[symbol])
# Write closing tag
self.out_stream.write("</expression>\n")
# integerConstant | stringConstant | keywordConstant | varName |
# varName '[' expression ']' | subroutineCall | '(' expression ')'
# | unaryOp term
def compile_term(self):
self.out_stream.write("<term>\n")
if self.tokenizer.get_token_type() == TokenType.INT_CONST:
self.write_terminal_tag(TokenType.INT_CONST,
self.tokenizer.get_int_val())
self.vm_writer.write_push(SegmentType.CONST,
self.tokenizer.get_int_val())
self.tokenizer.has_more_tokens()
elif self.tokenizer.get_token_type() == TokenType.STRING_CONST:
self.write_terminal_tag(TokenType.STRING_CONST,
self.tokenizer.get_string_val())
self.tokenizer.has_more_tokens()
elif self.tokenizer.get_token_type() == TokenType.KEYWORD \
and self.tokenizer.get_keyword_type() in keyword_constants:
# keyword constant
kc = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.KEYWORD, kc)
if kc == "null" or kc == "false":
# push const 0
self.vm_writer.write_push(SegmentType.CONST, 0)
elif kc == "true":
# push const -1
self.vm_writer.write_push(SegmentType.CONST, 1)
self.vm_writer.write_arithmetic(ArithmeticCType.NEG)
elif kc == "this":
# push pointer 0
self.vm_writer.write_push(SegmentType.POINTER, 0)
self.tokenizer.has_more_tokens()
elif self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
first_part, second_part = None, None
nArgs = 0
var_name = self.tokenizer.get_cur_ident()
first_part = var_name
var_props = self.lookup_st(var_name)
self.write_terminal_tag(TokenType.IDENTIFIER, var_name)
if var_props:
self.vm_writer.write_push(
self.var_t_to_segment_t(var_props["kind"]),
var_props["index"])
# Move to next token
self.tokenizer.has_more_tokens()
if self.tokenizer.get_token_type() == TokenType.SYMBOL:
# Handle varName '[' expression ']'
if self.tokenizer.get_symbol() == "[":
self.eat("[")
self.write_terminal_tag(TokenType.SYMBOL, "[")
self.tokenizer.has_more_tokens()
self.compile_expression()
self.eat(']')
self.write_terminal_tag(TokenType.SYMBOL, "]")
# add
self.vm_writer.write_arithmetic(ArithmeticCType.ADD)
# pop pointer 1
self.vm_writer.write_pop(SegmentType.POINTER, 1)
# push that 0
self.vm_writer.write_push(SegmentType.THAT, 0)
# Move to next token
self.tokenizer.has_more_tokens()
# Handle subroutineCall
elif self.tokenizer.get_symbol() == "(" \
or self.tokenizer.get_symbol() == ".":
# Is a method call
if self.tokenizer.get_symbol() == ".":
self.write_terminal_tag(TokenType.SYMBOL, ".")
# Move to next token
self.tokenizer.has_more_tokens()
# Handle subroutineCall
if self.tokenizer.get_token_type(
) == TokenType.IDENTIFIER:
second_part = self.tokenizer.get_cur_ident()
self.write_terminal_tag(TokenType.IDENTIFIER,
second_part)
else:
raise AssertionError(
"Not a valid subroutine/class name!!!")
# Move to next token
self.tokenizer.has_more_tokens()
self.eat("(")
self.write_terminal_tag(TokenType.SYMBOL, "(")
# Move to next token
self.tokenizer.has_more_tokens()
self.out_stream.write("<expressionList>\n")
if not (self.tokenizer.get_token_type() == TokenType.SYMBOL \
and self.tokenizer.get_symbol() == ")"):
nArgs = self.compile_expression_list()
self.out_stream.write("</expressionList>\n")
self.eat(")")
self.write_terminal_tag(TokenType.SYMBOL, ")")
# Move to next token
self.tokenizer.has_more_tokens()
if var_props:
print("Looked up: ", var_name)
# Is it a method call?
if second_part:
# Of some other class
self.vm_writer.write_call(
f"{var_props['type']}.{second_part}", nArgs + 1)
# This is no variable with given name
else:
if second_part:
# Of some other class
self.vm_writer.write_call(f"{first_part}.{second_part}",
nArgs)
else:
# Of this class
self.vm_writer.write_call(
f"{self.class_name}.{first_part}", nArgs)
elif self.tokenizer.get_token_type() == TokenType.SYMBOL:
# Handle '(' expression ')'
if self.tokenizer.get_symbol() == '(':
self.eat("(")
self.write_terminal_tag(TokenType.SYMBOL, "(")
self.tokenizer.has_more_tokens()
self.compile_expression()
self.eat(")")
self.write_terminal_tag(TokenType.SYMBOL, ")")
self.tokenizer.has_more_tokens()
# Handle unaryOp term
elif self.tokenizer.get_symbol() in allowed_unary_op:
unary_op = self.tokenizer.get_symbol()
self.write_terminal_tag(TokenType.SYMBOL,
self.tokenizer.get_symbol())
self.tokenizer.has_more_tokens()
self.compile_term()
self.vm_writer.write_arithmetic(allowed_unary_op[unary_op])
else:
raise AssertionError("( or unary Op expected!!")
self.out_stream.write("</term>\n")
# expression (',' expression)*
def compile_expression_list(self):
self.compile_expression()
arg_count = 1
while (self.tokenizer.get_token_type() == TokenType.SYMBOL) \
and (self.tokenizer.get_symbol() == ","):
self.write_terminal_tag(TokenType.SYMBOL, ",")
self.tokenizer.has_more_tokens()
self.compile_expression()
arg_count += 1
return arg_count
# eat the given string, else raise error
def eat(self, string):
if self.tokenizer.get_token_type() == TokenType.SYMBOL:
if not (self.tokenizer.get_symbol() == string):
raise AssertionError(
f"Expected symbol {string}, found: {self.tokenizer.get_symbol()}"
)
else:
raise AssertionError("Symbol not found!!")
# Utility method to check weather
# the current token is a valid data type
def is_valid_type(self):
# If built-in data type
if self.tokenizer.get_token_type() == TokenType.KEYWORD:
# if int, char, boolean
if self.tokenizer.get_keyword_type() in data_types:
return True
# If custom data type
elif self.tokenizer.get_token_type() == TokenType.IDENTIFIER:
return True
# Invalid data type
return False
# Lookup variable in symbol table
def lookup_st(self, v_name):
'''return variable properties'''
# FOR DEBUGGING
from pprint import pprint
pprint(self.subroutine_level_st.hash_map)
pprint(self.class_level_st.hash_map)
# To store looked up props
v_props = {}
# lookup subroutine level table
v_kind = self.subroutine_level_st.get_kind_of(v_name)
# var not found in subroutine level st
if v_kind == SymbolKind.NONE:
# lookup class level table
v_kind = self.class_level_st.get_kind_of(v_name)
if v_kind == SymbolKind.NONE:
return False
v_props["kind"] = v_kind
v_props["type"] = self.class_level_st.get_type_of(v_name)
v_props["index"] = self.class_level_st.get_index_of(v_name)
# return class level variable data
return v_props
# Data found for subroutine level table
v_props["kind"] = v_kind
v_props["type"] = self.subroutine_level_st.get_type_of(v_name)
v_props["index"] = self.subroutine_level_st.get_index_of(v_name)
return v_props
def var_t_to_segment_t(self, v_kind: SymbolKind) -> SegmentType:
if v_kind == SymbolKind.STATIC:
return SegmentType.STATIC
elif v_kind == SymbolKind.ARG:
return SegmentType.ARG
elif v_kind == SymbolKind.VAR:
return SegmentType.LOCAL
elif v_kind == SymbolKind.FEILD:
return SegmentType.THIS
else:
raise AssertionError("No segment kind for given v_kind!!")