class CompilationEngine:
def __init__(self, source):
self.if_counter = 0
self.while_counter = 0
self.tokenizer = Tokenizer(source)
self.tokenizer.has_more_tokens()
self.tokenizer.advance()
self.symbols = SymbolTable()
self.writer = VMWriter(source)
self.arithmetic_op = {}
self.init_op()
self.root = Element(CLASS)
self.class_name = ""
self.compile_class(self.root)
self.writer.close()
def init_op(self):
self.arithmetic_op = {
'+': "add",
'-': "sub",
'*': "call Math.multiply 2",
'/': "call Math.divide 2",
'&': "and",
'|': "or",
'<': "lt",
'>': "gt",
'=': "eq"
}
def next(self):
"""
Proceed to the next token.
:return:
"""
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
def compile_expression(self, caller):
"""
Compiles an expression.
:param caller:
:return:
"""
op_stack = []
self.compile_term(SubElement(caller, TERM))
while self.tokenizer.token_type(
) is JTok.SYMBOL and self.tokenizer.symbol() in OPERATORS:
op_stack.append(self.tokenizer.symbol())
self.next()
self.compile_term(SubElement(caller, TERM))
while op_stack:
self.writer.write_arithmetic(self.arithmetic_op[op_stack.pop()])
def compile_expressionList(self, caller):
"""
compiles a list of expressions
:param caller:
:return: num_of_args - number of expressions in expressions list.
used by function call
"""
num_of_args = 0
# if expression list is empty
if self.tokenizer.token_type(
) is JTok.SYMBOL and self.tokenizer.symbol() == ")":
caller.text = " "
return num_of_args
num_of_args += 1
self.compile_expression(SubElement(caller, EXPRESSION))
while self.tokenizer.token_type(
) is JTok.SYMBOL and self.tokenizer.symbol() == ",":
#SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
num_of_args += 1
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
return num_of_args
def compile_subroutineCall(self, caller, first_token):
"""
First token, the first identifier must be sent manually, so the method
expects the current token to be the second in the specification.
:param caller:
:param first_token:
:return:
"""
#SubElement(caller, IDENTIFIER).text = first_token
func_name = first_token
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
is_method = 0
if self.tokenizer.symbol() == '.':
self.next()
if self.symbols.kind_of(func_name): # If first token is var name
segment = self.symbols.kind_of(func_name)
segment = Kind.get_segment(segment)
index = self.symbols.index_of(func_name)
self.writer.write_push(segment, index)
func_name = self.symbols.type_of(func_name)
is_method = 1
func_name = func_name + "." + self.tokenizer.identifier()
#SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()
self.next()
#SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
else:
func_name = self.class_name + "." + func_name
self.writer.write_push(POINTER, 0)
is_method = 1
self.next()
num_of_args = self.compile_expressionList(
SubElement(caller, EXPRESSION_LIST)) + is_method
self.writer.write_call(func_name, num_of_args)
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
def compile_term(self, caller):
"""
:param caller:
:return:
"""
type = self.tokenizer.token_type()
if type is JTok.INT_CONST:
#SubElement(caller, INTEGER_CONSTANT).text = str(self.tokenizer.intVal())
self.writer.write_push(CONSTANT, self.tokenizer.intVal())
self.next()
elif type is JTok.STRING_CONST:
string_val = self.tokenizer.string_val()
self.writer.write_push(CONSTANT, len(string_val))
self.writer.write_call("String.new", 1)
for c in string_val:
self.writer.write_push(CONSTANT, ord(c))
self.writer.write_call("String.appendChar", 2)
self.next()
elif type is JTok.KEYWORD:
#SubElement(caller, KEYWORD).text = self.tokenizer.key_word()
if self.tokenizer.key_word() in {"null", "false"}:
self.writer.write_push(CONSTANT, 0)
elif self.tokenizer.key_word(
) == "true": # Assuming valid input, it must be true
self.writer.write_push(CONSTANT, 1)
self.writer.write_arithmetic("neg")
elif self.tokenizer.key_word() == "this":
self.writer.write_push(POINTER, 0)
else:
print("unexpected")
self.next()
elif type is JTok.IDENTIFIER:
name = self.tokenizer.identifier()
self.next()
type = self.tokenizer.token_type()
if type is JTok.SYMBOL and self.tokenizer.symbol() in {".", "("}:
self.compile_subroutineCall(caller, name)
elif type is JTok.SYMBOL and self.tokenizer.symbol(
) == '[': #TODO: Arrays, later
# SubElement(caller, IDENTIFIER).text = name
# SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
kind = self.symbols.kind_of(name)
index = self.symbols.index_of(name)
if kind is not None:
self.writer.write_push(kind.get_segment(), index)
else:
print("unexpected")
self.writer.write_arithmetic("add")
self.writer.write_pop(POINTER, 1)
self.writer.write_push("that", 0)
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
else:
#SubElement(caller, IDENTIFIER).text = name
kind = self.symbols.kind_of(name)
index = self.symbols.index_of(name)
if kind is not None:
self.writer.write_push(kind.get_segment(), index)
else:
print("unexpected")
elif type is JTok.SYMBOL:
if self.tokenizer.symbol() == '(':
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
elif self.tokenizer.symbol() in {'-', '~'}:
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
unary_op = self.tokenizer.symbol()
self.next()
self.compile_term(SubElement(caller, TERM))
if unary_op == "-":
self.writer.write_arithmetic("neg")
elif unary_op == "~":
self.writer.write_arithmetic("not")
else:
"unexpected"
def compile_do(self, caller):
"""
format : 'do' subroutineCall ';'
:param caller:
:return:
"""
#SubElement(caller, KEYWORD).text = self.tokenizer.key_word()
self.next()
name = self.tokenizer.identifier()
self.next()
self.compile_subroutineCall(caller, name)
self.writer.write_pop(TEMP, 0)
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ';'
self.next()
def compile_let(self, caller):
"""
format : 'let' varName ( '[' expression ']' )? '=' expression ';'
:param caller:
:return:
"""
self.next() # skip 'let'
varName = self.tokenizer.identifier()
self.next()
kind = self.symbols.kind_of(varName)
kind = kind.get_segment()
index = self.symbols.index_of(varName)
if self.tokenizer.symbol() == '[': # if array
self.next() # skip [
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_push(kind, index)
self.writer.write_arithmetic("add")
self.next() # skip ]
self.next() # skip =
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_pop(TEMP, 0)
self.writer.write_pop(POINTER, 1)
self.writer.write_push(TEMP, 0)
self.writer.write_pop("that", 0)
else:
self.next() # skip =
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_pop(kind, index)
self.next() # skip ;
def compile_return(self, caller):
"""
format : 'return' expression? ';'
:param caller:
:return:
"""
#SubElement(caller,KEYWORD).text = self.tokenizer.identifier()
self.next()
if self.tokenizer.token_type(
) is JTok.SYMBOL and self.tokenizer.symbol() == ";":
#SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.writer.write_push(CONSTANT, 0)
self.writer.write_return()
self.next()
return
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_return()
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
def compile_while(self, caller):
"""
format : 'while' '(' expression ')' '{' statements '}'
:param caller:
:return:
"""
while_index = self.while_counter
self.while_counter += 1
self.writer.write_label("WHILE_EXP" + str(while_index))
self.next() # skip while
self.next() # skip (
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_arithmetic("not")
self.writer.write_if("WHILE_END" + str(while_index))
self.next() # skip )
self.next() # skip {
self.compile_statements(SubElement(caller, STATEMENTS))
self.writer.write_goto("WHILE_EXP" + str(while_index))
self.writer.write_label("WHILE_END" + str(while_index))
self.next() # skip }
def compile_statements(self, caller):
"""
:param caller:
:return:
"""
STATEMENTS = {'do', 'while', 'let', 'return', 'if'}
caller.text = " "
while self.tokenizer.token_type(
) is JTok.KEYWORD and self.tokenizer.key_word() in STATEMENTS:
if self.tokenizer.key_word() == 'do':
self.compile_do(SubElement(caller, 'doStatement'))
elif self.tokenizer.key_word() == 'while':
self.compile_while(SubElement(caller, 'whileStatement'))
elif self.tokenizer.key_word() == 'let':
self.compile_let(SubElement(caller, 'letStatement'))
elif self.tokenizer.key_word() == 'return':
self.compile_return(SubElement(caller, 'returnStatement'))
elif self.tokenizer.key_word() == 'if':
self.compile_if(SubElement(caller, 'ifStatement'))
def compile_if(self, caller):
"""
format : 'if' '(' expression ')' '{' statements '}'
( 'else' '{' statements '}' )?
:param caller:
:return:
"""
self.next() # (
self.compile_expression(caller)
self.next() # {
if_index = self.if_counter
self.if_counter += 1
self.writer.write_if("IF_TRUE" + str(if_index))
self.writer.write_goto("IF_FALSE" + str(if_index))
self.writer.write_label("IF_TRUE" + str(if_index))
self.compile_statements(caller)
self.next()
if self.tokenizer.key_word() == 'else':
self.writer.write_goto("IF_END" + str(if_index))
self.writer.write_label("IF_FALSE" + str(if_index))
self.next() # else
self.next() # {
self.compile_statements(caller)
self.next() # }
self.writer.write_label("IF_END" + str(if_index))
else:
self.writer.write_label("IF_FALSE" + str(if_index))
return
def compile_var_dec(self, caller):
"""
format: 'var' type varName ( ',' varName)* ';'
:param caller:
:return:
"""
kind = self.tokenizer.key_word()
#SubElement(caller, KEYWORD).text = kind # set var as keyword
self.next()
return self.compile_list_of_vars(caller, "var", Kind[kind])
def compile_class(self, caller):
"""
:param caller:
:return:
"""
SubElement(caller, KEYWORD).text = self.tokenizer.key_word()
self.next()
SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()
self.class_name = self.tokenizer.identifier()
self.next()
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() #{
self.next()
while self.tokenizer.token_type(
) is JTok.KEYWORD and self.tokenizer.key_word() in {'static', 'field'}:
self.compile_classVarDec(SubElement(caller, "classVarDec"))
while not self.tokenizer.token_type() is JTok.SYMBOL:
self.compile_subroutine(SubElement(caller, "subroutineDec"))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() #}
self.next()
def compile_list_of_vars(self, caller, category, kind):
"""
Helper method to compile lists of variables according to
type varName (',' varName)*
:param caller:
:return:
"""
num_of_vars = 0
type = self.compile_type(caller)
self.symbols.define(self.tokenizer.identifier(), type, kind)
num_of_vars += 1
#text = category+", defined, "+type+", "+kind.name+", "+str(self.symbols.index_of(self.tokenizer.identifier()))
#SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()+", "+text # set var name as identifier
self.next()
while self.tokenizer.symbol() != ';':
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ','
self.next()
self.symbols.define(self.tokenizer.identifier(), type, kind)
num_of_vars += 1
#text = category + ", defined, " + type + ", " + kind.name + ", " + str(
# self.symbols.index_of(self.tokenizer.identifier()))
#SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()+", "+text # set var name
self.next()
#SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ';'
self.next()
return num_of_vars
def compile_classVarDec(self, caller):
"""
:param caller:
:return:
"""
kind = self.tokenizer.key_word()
#SubElement(caller,KEYWORD).text = kind
self.next()
self.compile_list_of_vars(caller, kind, Kind[kind])
def compile_type(self, caller):
"""
Compiles a tag according to type, for variables
:param caller:
:return:
"""
tag = KEYWORD if self.tokenizer.token_type(
) is JTok.KEYWORD else IDENTIFIER
text = self.tokenizer.key_word(
) if tag is KEYWORD else self.tokenizer.identifier()
SubElement(caller, tag).text = text
self.next()
return text
def compile_subroutine(self, caller):
"""
:param caller:
:return:
"""
subroutine_type = self.tokenizer.key_word()
self.next()
# Just to skip void or type
if self.tokenizer.token_type(
) is JTok.KEYWORD and self.tokenizer.key_word() == "void":
SubElement(caller, KEYWORD).text = self.tokenizer.key_word()
self.next()
else:
self.compile_type(caller)
name = self.class_name + "." + self.tokenizer.identifier()
self.symbols.start_subroutine()
self.next()
self.next() # Skips (
if subroutine_type == "method":
self.symbols.define("this", "", Kind.arg)
self.compile_parameterList(SubElement(caller, "parameterList"))
self.next() # Skips )
self.next() # Skips {
num_of_locals = 0
while self.tokenizer.token_type(
) is JTok.KEYWORD and self.tokenizer.key_word() == "var":
num_of_locals += self.compile_var_dec(SubElement(caller, "varDec"))
self.writer.write_function(name, num_of_locals)
if subroutine_type == "constructor":
self.writer.write_push(CONSTANT,
self.symbols.var_count(Kind.field))
self.writer.write_call("Memory.alloc", 1)
self.writer.write_pop(POINTER, 0)
elif subroutine_type == "method":
self.writer.write_push(ARGUMENT, 0)
self.writer.write_pop(POINTER, 0)
self.compile_statements(SubElement(caller, "statements"))
self.next() # Skips }
def compile_parameterList(self, caller):
"""
:param caller:
:return:
"""
if self.tokenizer.token_type(
) is JTok.SYMBOL and self.tokenizer.symbol() == ")":
caller.text = " "
return
type = self.compile_type(caller)
name = self.tokenizer.identifier()
# SubElement(caller,IDENTIFIER).text = self.tokenizer.identifier()
self.symbols.define(name, type, Kind.arg)
self.next()
while self.tokenizer.token_type(
) is JTok.SYMBOL and self.tokenizer.symbol() == ",":
# SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
type = self.compile_type(caller)
name = self.tokenizer.identifier()
self.symbols.define(name, type, Kind.arg)
#SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()
self.next()
class CompilationEngine:
def __init__(self, source):
self.tokenizer = Tokenizer(source)
self.tokenizer.has_more_tokens()
self.tokenizer.advance()
self.root = Element(CLASS)
self.compile_class(self.root)
def next(self):
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
def get_xml(self):
"""
Returns a textual XML representation of the program structure.
:return:
"""
return prettify(self.root)[23:]
def compile_expression(self,caller):
"""
Compiles an expression.
:param caller:
:return:
"""
self.compile_term(SubElement(caller,TERM))
while self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() in OPERATORS:
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_term(SubElement(caller,TERM))
def compile_expressionList(self,caller):
"""
:param caller:
:return:
"""
# if expression list is empty
if self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ")":
caller.text = "\n"
return
self.compile_expression(SubElement(caller,EXPRESSION))
while self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ",":
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_expression(SubElement(caller,EXPRESSION))
def compile_subroutineCall(self,caller,first_token):
"""
First token, the first identifier must be sent manually, so the method
expects the current token to be the second in the specification.
:param caller:
:param first_token:
:return:
"""
SubElement(caller, IDENTIFIER).text = first_token
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
if self.tokenizer.symbol() == '.':
self.next()
SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()
self.next()
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_expressionList(SubElement(caller, EXPRESSION_LIST))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
def compile_term(self,caller):
"""
:param caller:
:return:
"""
type = self.tokenizer.token_type()
if type is JTok.INT_CONST:
SubElement(caller, INTEGER_CONSTANT).text = str(self.tokenizer.intVal())
self.next()
elif type is JTok.STRING_CONST:
SubElement(caller, STRING_CONSTANT).text = self.tokenizer.string_val()
self.next()
elif type is JTok.KEYWORD:
SubElement(caller, KEYWORD).text = self.tokenizer.key_word()
self.next()
elif type is JTok.IDENTIFIER:
name = self.tokenizer.identifier()
self.next()
type = self.tokenizer.token_type()
if type is JTok.SYMBOL and self.tokenizer.symbol() in {".", "("}:
self.compile_subroutineCall(caller,name)
elif type is JTok.SYMBOL and self.tokenizer.symbol() == '[':
SubElement(caller, IDENTIFIER).text = name
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
else:
SubElement(caller, IDENTIFIER).text = name
elif type is JTok.SYMBOL:
if self.tokenizer.symbol() == '(':
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
elif self.tokenizer.symbol() in {'-','~'}:
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_term(SubElement(caller,TERM))
def compile_do(self, caller):
"""
format : 'do' subroutineCall ';'
:param caller:
:return:
"""
SubElement(caller, KEYWORD).text = self.tokenizer.key_word()
self.next()
name = self.tokenizer.identifier()
self.next()
self.compile_subroutineCall(caller,name)
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ';'
self.next()
def compile_let(self, caller):
"""
format : 'let' varName ( '[' expression ']' )? '=' expression ';'
:param caller:
:return:
"""
SubElement(caller, KEYWORD).text = self.tokenizer.key_word() # set 'let' as text
self.next()
SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier() # varName
self.next()
if self.tokenizer.symbol() == '[':
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '['
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ']'
self.next()
# If there is no expression to compile:
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '='
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ';'
self.next()
def compile_return(self, caller):
"""
format : 'return' expression? ';'
:param caller:
:return:
"""
SubElement(caller,KEYWORD).text = self.tokenizer.identifier()
self.next()
if self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ";":
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
return
self.compile_expression(SubElement(caller,EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol()
self.next()
def compile_while(self, caller):
"""
format : 'while' '(' expression ')' '{' statements '}'
:param caller:
:return:
"""
SubElement(caller, KEYWORD).text = self.tokenizer.key_word() # set 'while' as text
self.next()
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '('
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ')'
self.next()
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '{'
self.next()
self.compile_statements(SubElement(caller, STATEMENTS))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '}'
self.next()
def compile_statements(self, caller):
"""
:param caller:
:return:
"""
STATEMENTS = {'do','while','let','return','if'}
run_once = False
while self.tokenizer.token_type() is JTok.KEYWORD and self.tokenizer.key_word() in STATEMENTS:
run_once = True
if self.tokenizer.key_word() == 'do':
self.compile_do(SubElement(caller, 'doStatement'))
elif self.tokenizer.key_word() == 'while':
self.compile_while(SubElement(caller, 'whileStatement'))
elif self.tokenizer.key_word() == 'let':
self.compile_let(SubElement(caller, 'letStatement'))
elif self.tokenizer.key_word() == 'return':
self.compile_return(SubElement(caller, 'returnStatement'))
elif self.tokenizer.key_word() == 'if':
self.compile_if(SubElement(caller, 'ifStatement'))
if not run_once:
caller.text = "\n"
def compile_if(self, caller):
"""
format : 'if' '(' expression ')' '{' statements '}'
( 'else' '{' statements '}' )?
:param caller:
:return:
"""
SubElement(caller,
KEYWORD).text = self.tokenizer.key_word() # set 'if' as text
self.next()
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '('
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ')'
self.next()
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '{'
self.next()
self.compile_statements(SubElement(caller, STATEMENTS))
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set '}'
self.next()
if self.tokenizer.token_type() is JTok.KEYWORD and self.tokenizer.key_word() == 'else':
SubElement(caller,
KEYWORD).text = self.tokenizer.key_word() # set 'else' as text
self.next()
SubElement(caller,
SYMBOL).text = self.tokenizer.symbol() # set '{'
self.next()
self.compile_statements(SubElement(caller, STATEMENTS))
SubElement(caller,
SYMBOL).text = self.tokenizer.symbol() # set '}'
self.next()
def compile_var_dec(self, caller):
"""
format: 'var' type varName ( ',' varName)* ';'
:param caller:
:return:
"""
SubElement(caller, KEYWORD).text = self.tokenizer.key_word() # set var as keyword
self.next()
self.compile_list_of_vars(caller)
def compile_class(self,caller):
"""
:param caller:
:return:
"""
SubElement(caller,KEYWORD).text = self.tokenizer.key_word()
self.next()
SubElement(caller,IDENTIFIER).text = self.tokenizer.identifier()
self.next()
SubElement(caller,SYMBOL).text = self.tokenizer.symbol() #{
self.next()
while self.tokenizer.token_type() is JTok.KEYWORD and self.tokenizer.key_word() in {'static','field'}:
self.compile_classVarDec(SubElement(caller,"classVarDec"))
while not self.tokenizer.token_type() is JTok.SYMBOL:
self.compile_subroutine(SubElement(caller,"subroutineDec"))
SubElement(caller,SYMBOL).text = self.tokenizer.symbol() #}
self.next()
def compile_list_of_vars(self,caller):
"""
Helper method to compile lists of variables according to
type varName (',' varName)*
:param caller:
:return:
"""
self.compile_type(caller)
SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier() # set var name as identifier
self.next()
while self.tokenizer.symbol() != ';':
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ','
self.next()
SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier() # set var name
self.next()
SubElement(caller, SYMBOL).text = self.tokenizer.symbol() # set ';'
self.next()
def compile_classVarDec(self,caller):
"""
:param caller:
:return:
"""
SubElement(caller,KEYWORD).text = self.tokenizer.key_word()
self.next()
self.compile_list_of_vars(caller)
def compile_type(self,caller):
"""
Compiles a tag according to type, for variables
:param caller:
:return:
"""
tag = KEYWORD if self.tokenizer.token_type() is JTok.KEYWORD else IDENTIFIER
text = self.tokenizer.key_word() if tag is KEYWORD else self.tokenizer.identifier()
SubElement(caller, tag).text = text
self.next()
def compile_subroutine(self,caller):
"""
:param caller:
:return:
"""
SubElement(caller,KEYWORD).text = self.tokenizer.key_word()
self.next()
if self.tokenizer.token_type() is JTok.KEYWORD and self.tokenizer.key_word() == "void":
SubElement(caller,KEYWORD).text = self.tokenizer.key_word()
self.next()
else:
self.compile_type(caller)
SubElement(caller,IDENTIFIER).text = self.tokenizer.identifier()
self.next()
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_parameterList(SubElement(caller,"parameterList"))
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_subroutineBody(SubElement(caller,"subroutineBody"))
def compile_subroutineBody(self,caller):
"""
Compiles a subroutine body
:param caller:
:return:
"""
SubElement(caller,SYMBOL).text = self.tokenizer.symbol() #{
self.next()
while self.tokenizer.token_type() is JTok.KEYWORD and self.tokenizer.key_word() == "var":
self.compile_var_dec(SubElement(caller,"varDec"))
self.compile_statements(SubElement(caller,"statements"))
SubElement(caller,SYMBOL).text = self.tokenizer.symbol() #}
self.next()
def compile_parameterList(self,caller):
"""
:param caller:
:return:
"""
if self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ")":
caller.text = "\n"
return
self.compile_type(caller)
SubElement(caller,IDENTIFIER).text = self.tokenizer.identifier()
self.next()
while self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ",":
SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
self.next()
self.compile_type(caller)
SubElement(caller, IDENTIFIER).text = self.tokenizer.identifier()
self.next()
class CompilationEngine:
def __init__(self, source):
self.if_counter = 0
self.while_counter = 0
self.tokenizer = Tokenizer(source)
self.tokenizer.has_more_tokens()
self.tokenizer.advance()
self.symbols = SymbolTable()
self.writer = VMWriter(source)
self.arithmetic_op = {}
self.init_op()
self.root = Element(CLASS)
self.class_name = ""
self.compile_class(self.root)
self.writer.close()
def init_op(self):
self.arithmetic_op = {'+': "add",
'-': "sub",
'*': "call Math.multiply 2",
'/': "call Math.divide 2",
'&': "and",
'|': "or",
'<': "lt",
'>': "gt",
'=': "eq"
}
def next(self):
"""
Proceed to the next token.
:return:
"""
if self.tokenizer.has_more_tokens():
self.tokenizer.advance()
def compile_expression(self,caller):
"""
Compiles an expression.
:param caller:
:return:
"""
op_stack = []
self.compile_term(SubElement(caller,TERM))
while self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() in OPERATORS:
op_stack.append(self.tokenizer.symbol())
self.next()
self.compile_term(SubElement(caller,TERM))
while op_stack:
self.writer.write_arithmetic(self.arithmetic_op[op_stack.pop()])
def compile_expressionList(self,caller):
num_of_args = 0
# if expression list is empty
if self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ")":
caller.text = " "
return num_of_args
num_of_args += 1
self.compile_expression(SubElement(caller,EXPRESSION))
while self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ",":
#SubElement(caller,SYMBOL).text = self.tokenizer.symbol()
num_of_args += 1
self.next()
self.compile_expression(SubElement(caller,EXPRESSION))
return num_of_args
def compile_subroutineCall(self,caller,first_token):
func_name = first_token
is_method = 0
if self.tokenizer.symbol() == '.':
self.next()
if self.symbols.kind_of(func_name):
segment = self.symbols.kind_of(func_name)
segment = Kind.get_segment(segment)
index = self.symbols.index_of(func_name)
self.writer.write_push(segment,index)
func_name = self.symbols.type_of(func_name)
is_method = 1
func_name = func_name+"."+self.tokenizer.identifier()
self.next()
else:
func_name = self.class_name+"."+func_name
self.writer.write_push(POINTER,0)
is_method = 1
self.next()
num_of_args = self.compile_expressionList(SubElement(caller, EXPRESSION_LIST))+is_method
self.writer.write_call(func_name,num_of_args)
self.next()
def compile_term(self,caller):
type = self.tokenizer.token_type()
if type is JTok.INT_CONST:
self.writer.write_push(CONSTANT,self.tokenizer.intVal())
self.next()
elif type is JTok.STRING_CONST:
string_val = self.tokenizer.string_val()
self.writer.write_push(CONSTANT,len(string_val))
self.writer.write_call("String.new", 1)
for c in string_val:
self.writer.write_push(CONSTANT,ord(c))
self.writer.write_call("String.appendChar", 2)
self.next()
elif type is JTok.KEYWORD:
if self.tokenizer.key_word() in {"null", "false"}:
self.writer.write_push(CONSTANT, 0)
elif self.tokenizer.key_word() == "true":
self.writer.write_push(CONSTANT, 1)
self.writer.write_arithmetic("neg")
elif self.tokenizer.key_word() == "this":
self.writer.write_push(POINTER, 0)
else:
print("unexpected")
self.next()
elif type is JTok.IDENTIFIER:
name = self.tokenizer.identifier()
self.next()
type = self.tokenizer.token_type()
if type is JTok.SYMBOL and self.tokenizer.symbol() in {".", "("}:
self.compile_subroutineCall(caller,name)
elif type is JTok.SYMBOL and self.tokenizer.symbol() == '[':
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
kind = self.symbols.kind_of(name)
index = self.symbols.index_of(name)
if kind is not None:
self.writer.write_push(kind.get_segment(),index)
else:
print("unexpected")
self.writer.write_arithmetic("add")
self.writer.write_pop(POINTER,1)
self.writer.write_push("that",0)
self.next()
else:
kind = self.symbols.kind_of(name)
index = self.symbols.index_of(name)
if kind is not None:
self.writer.write_push(kind.get_segment(),index)
else:
print("unexpected")
elif type is JTok.SYMBOL:
if self.tokenizer.symbol() == '(':
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
self.next()
elif self.tokenizer.symbol() in {'-','~'}:
unary_op = self.tokenizer.symbol()
self.next()
self.compile_term(SubElement(caller,TERM))
if unary_op == "-":
self.writer.write_arithmetic("neg")
elif unary_op == "~":
self.writer.write_arithmetic("not")
else:
"unexpected"
def compile_do(self, caller):
self.next()
name = self.tokenizer.identifier()
self.next()
self.compile_subroutineCall(caller,name)
self.writer.write_pop(TEMP,0)
self.next()
def compile_let(self, caller):
self.next()
varName = self.tokenizer.identifier()
self.next()
kind = self.symbols.kind_of(varName)
kind = kind.get_segment()
index = self.symbols.index_of(varName)
if self.tokenizer.symbol() == '[':
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_push(kind,index)
self.writer.write_arithmetic("add")
self.next()
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_pop(TEMP,0)
self.writer.write_pop(POINTER,1)
self.writer.write_push(TEMP,0)
self.writer.write_pop("that",0)
else:
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_pop(kind,index)
self.next()
def compile_return(self, caller):
self.next()
if self.tokenizer.token_type() is JTok.SYMBOL and self.tokenizer.symbol() == ";":
self.writer.write_push(CONSTANT, 0)
self.writer.write_return()
self.next()
return
self.compile_expression(SubElement(caller,EXPRESSION))
self.writer.write_return()
self.next()
def compile_while(self, caller):
while_index = self.while_counter
self.while_counter += 1
self.writer.write_label("WHILE_EXP"+str(while_index))
self.next()
self.next()
self.compile_expression(SubElement(caller, EXPRESSION))
self.writer.write_arithmetic("not")
self.writer.write_if("WHILE_END"+str(while_index))
self.next()
self.next()
self.compile_statements(SubElement(caller, STATEMENTS))
self.writer.write_goto("WHILE_EXP"+str(while_index))
self.writer.write_label("WHILE_END"+str(while_index))
self.next()
def compile_statements(self, caller):
STATEMENTS = {'do','while','let','return','if'}
caller.text = " "
while self.tokenizer.token_type() is JTok.KEYWORD and self.tokenizer.key_word() in STATEMENTS:
if self.tokenizer.key_word() == 'do':
self.compile_do(SubElement(caller, 'doStatement'))
elif self.tokenizer.key_word() == 'while':
self.compile_while(SubElement(caller, 'whileStatement'))
elif self.tokenizer.key_word() == 'let':
self.compile_let(SubElement(caller, 'letStatement'))
elif self.tokenizer.key_word() == 'return':
self.compile_return(SubElement(caller, 'returnStatement'))
elif self.tokenizer.key_word() == 'if':
self.compile_if(SubElement(caller, 'ifStatement'))
def compile_if(self, caller):
self.next() # (
self.compile_expression(caller)
self.next() # {
if_index = self.if_counter
self.if_counter += 1
self.writer.write_if("IF_TRUE" + str(if_index))
self.writer.write_goto("IF_FALSE" + str(if_index))
self.writer.write_label("IF_TRUE" + str(if_index))
self.compile_statements(caller)
self.next()
if self.tokenizer.key_word() == 'else':
self.writer.write_goto("IF_END" + str(if_index))
self.writer.write_label("IF_FALSE" + str(if_index))
self.next()
self.next()
self.compile_statements(caller)
self.next()
self.writer.write_label("IF_END" + str(if_index))
else:
self.writer.write_label("IF_FALSE" + str(if_index))
return