class CompilationEngine:
CLASS_VAR_DEC_KEYWORDS = ['static', 'field']
SUBROUTINE_DEC_KEYWORDS = ['constructor', 'function', 'method']
BINARY_OPERATOR_SYMBOLS = ['+', '-', '*', '/', '&', '|', '<', '>', '=']
UNARY_OPERATOR_SYMBOLS = ['-', '~']
BINARY_OPERATORS_TO_COMMAND = {
'+': 'add',
'-': 'sub',
'=': 'eq',
'>': 'gt',
'<': 'lt',
'&': 'and',
'|': 'or'
}
UNARY_OPERATORS_TO_COMMAND = {'-': 'neg', '~': 'not'}
TYPE_TO_TAG = {
'STRING_CONST': 'stringConstant',
'INT_CONST': 'integerConstant',
'KEYWORD': 'keyword',
'IDENTIFIER': 'identifier',
'SYMBOL': 'symbol'
}
SYMBOLS_TO_XML_CONVENTION = {
'<': '<',
'>': '>',
'&': '&',
'"': '"'
}
def __init__(self, input_file_path, vm_writer: VMWriter):
self.jack_tokenizer = JackTokenizer(input_file_path)
self.symbol_table = SymbolTable()
self.vm_writer = vm_writer
if self.jack_tokenizer.has_more_tokens():
self.compile_class()
def compile_class(self):
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(), 'NONE',
'CLASS')
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
if self.jack_tokenizer.key_word(
) in CompilationEngine.CLASS_VAR_DEC_KEYWORDS:
self.compile_class_var_dec()
if self.jack_tokenizer.key_word(
) in CompilationEngine.SUBROUTINE_DEC_KEYWORDS:
self.compile_subroutine()
self.jack_tokenizer.advance()
self.vm_writer.close()
def write_token(self, token_name):
type_tag = CompilationEngine.TYPE_TO_TAG[
self.jack_tokenizer.token_type()]
self.output_file.write('<{0}> {1} </{0}>\n'.format(
type_tag, token_name))
self.jack_tokenizer.advance()
def compile_class_var_dec(self):
while self.jack_tokenizer.key_word(
) in CompilationEngine.CLASS_VAR_DEC_KEYWORDS:
kind = ''
if self.jack_tokenizer.key_word() == 'field':
kind = 'FIELD'
elif self.jack_tokenizer.key_word() == 'static':
kind = 'STATIC'
self.jack_tokenizer.advance()
field_type = self.get_type()
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(),
field_type, kind)
self.jack_tokenizer.advance()
while self.jack_tokenizer.symbol() != ';':
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(),
field_type, kind)
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
def write_type(self):
if self.jack_tokenizer.token_type() == 'KEYWORD':
self.write_token(self.jack_tokenizer.key_word())
elif self.jack_tokenizer.token_type() == 'IDENTIFIER':
self.write_token(self.jack_tokenizer.identifier())
def compile_subroutine(self):
self.vm_writer.zero_branching_indexes()
while self.jack_tokenizer.key_word(
) in CompilationEngine.SUBROUTINE_DEC_KEYWORDS:
self.symbol_table.start_subroutine()
constructor = True if self.jack_tokenizer.key_word(
) == 'constructor' else False
method = False
if self.jack_tokenizer.key_word() == 'method':
method = True
self.symbol_table.define('this',
self.symbol_table.get_class_name(),
'ARG')
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(), 'NONE',
'SUBROUTINE')
name = self.symbol_table.get_class_name(
) + '.' + self.jack_tokenizer.identifier()
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.compile_parameter_list()
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
var_num = 0
while self.jack_tokenizer.key_word() == 'var':
var_num += self.compile_var_dec()
self.vm_writer.write_function(name, var_num)
if method:
self.vm_writer.write_push('ARG', 0)
self.vm_writer.write_pop('POINTER', 0)
elif constructor:
field_count = self.symbol_table.var_count('FIELD')
self.vm_writer.write_push('CONST', field_count)
self.vm_writer.write_call('Memory.alloc', 1)
self.vm_writer.write_pop('POINTER', 0)
self.compile_statements()
self.jack_tokenizer.advance()
def compile_parameter_list(self):
if self.jack_tokenizer.symbol() != ')':
parameter_type = self.get_type()
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(),
parameter_type, 'ARG')
self.jack_tokenizer.advance()
while self.jack_tokenizer.symbol() == ",":
self.jack_tokenizer.advance()
parameter_type = self.get_type()
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(),
parameter_type, 'ARG')
self.jack_tokenizer.advance()
def get_type(self):
if self.jack_tokenizer.token_type() == 'KEYWORD':
parameter_type = self.jack_tokenizer.key_word()
elif self.jack_tokenizer.token_type() == 'IDENTIFIER':
parameter_type = self.jack_tokenizer.identifier()
return parameter_type
def compile_var_dec(self):
var_num = 1
self.jack_tokenizer.advance()
var_type = self.get_type()
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(), var_type,
'VAR')
self.jack_tokenizer.advance()
while self.jack_tokenizer.symbol() == ",":
var_num += 1
self.jack_tokenizer.advance()
self.symbol_table.define(self.jack_tokenizer.identifier(),
var_type, 'VAR')
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
return var_num
def compile_statements(self):
while self.jack_tokenizer.token_type() == 'KEYWORD':
if self.jack_tokenizer.key_word() == 'let':
self.compile_let()
elif self.jack_tokenizer.key_word() == 'if':
self.compile_if()
elif self.jack_tokenizer.key_word() == 'while':
self.compile_while()
elif self.jack_tokenizer.key_word() == 'do':
self.compile_do()
elif self.jack_tokenizer.key_word() == 'return':
self.compile_return()
def compile_do(self):
self.jack_tokenizer.advance()
name = self.jack_tokenizer.identifier()
self.jack_tokenizer.advance()
self.compile_subroutine_call(name)
# must dispose of void function return value
self.vm_writer.write_pop('TEMP', 0)
self.jack_tokenizer.advance()
def compile_subroutine_call(self, prefix_call=''):
if self.jack_tokenizer.symbol() == '(':
subroutine = False
# If not in symbol table - then subroutine
if not self.symbol_table.kind_of(
prefix_call) or self.symbol_table.kind_of(
prefix_call) == 'SUBROUTINE':
subroutine = True
self.jack_tokenizer.advance()
args_count = 0
if subroutine:
self.vm_writer.write_push('POINTER', 0)
args_count += 1
args_count += self.compile_expression_list()
if subroutine:
self.vm_writer.write_call(
self.symbol_table.get_class_name() + '.' + prefix_call,
args_count)
else:
self.vm_writer.write_call(prefix_call, args_count)
self.jack_tokenizer.advance()
elif self.jack_tokenizer.symbol() == '.':
variable = False
self.jack_tokenizer.advance()
if self.symbol_table.kind_of(prefix_call) in ['VAR', 'FIELD']:
variable = True
variable_name = prefix_call
prefix_call = self.symbol_table.type_of(prefix_call)
prefix_call += '.{0}'.format(self.jack_tokenizer.identifier())
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
args_count = 0
if variable:
self.vm_writer.write_push(
self.symbol_table.kind_of(variable_name),
self.symbol_table.index_of(variable_name))
args_count += 1
args_count += self.compile_expression_list()
self.vm_writer.write_call(prefix_call, args_count)
self.jack_tokenizer.advance()
def compile_let(self):
self.jack_tokenizer.advance()
var_name = self.jack_tokenizer.identifier()
self.jack_tokenizer.advance()
if self.jack_tokenizer.symbol() == '[':
self.vm_writer.write_push(self.symbol_table.kind_of(var_name),
self.symbol_table.index_of(var_name))
self.jack_tokenizer.advance()
self.compile_expression()
self.vm_writer.write_arithmetic("add")
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.compile_expression()
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:
self.jack_tokenizer.advance()
self.compile_expression()
self.vm_writer.write_pop(self.symbol_table.kind_of(var_name),
self.symbol_table.index_of(var_name))
self.jack_tokenizer.advance()
def compile_while(self):
while_idx = self.vm_writer.get_next_label_index('while')
if_label = 'WHILE_IF_{0}'.format(while_idx)
end_label = 'WHILE_END_{0}'.format(while_idx)
self.vm_writer.write_label(if_label)
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.compile_expression()
self.vm_writer.write_arithmetic('not')
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.vm_writer.write_if(end_label)
self.compile_statements()
self.vm_writer.write_goto(if_label)
self.jack_tokenizer.advance()
self.vm_writer.write_label(end_label)
def compile_return(self):
self.jack_tokenizer.advance()
if self.jack_tokenizer.symbol() != ';':
self.compile_expression()
else:
self.vm_writer.write_push('CONST', 0)
self.vm_writer.write_return()
self.jack_tokenizer.advance()
def compile_if(self):
if_idx = self.vm_writer.get_next_label_index('if')
else_label = 'IF_ELSE_{0}'.format(if_idx)
end_label = 'IF_END_{0}'.format(if_idx)
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.compile_expression()
self.vm_writer.write_arithmetic('not')
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.vm_writer.write_if(else_label)
self.compile_statements()
self.jack_tokenizer.advance()
self.vm_writer.write_goto(end_label)
self.vm_writer.write_label(else_label)
if self.jack_tokenizer.key_word() == 'else':
self.jack_tokenizer.advance()
self.jack_tokenizer.advance()
self.compile_statements()
self.jack_tokenizer.advance()
self.vm_writer.write_label(end_label)
def compile_expression(self):
self.compile_term()
while self.jack_tokenizer.symbol(
) in CompilationEngine.BINARY_OPERATOR_SYMBOLS:
symbol = self.jack_tokenizer.symbol()
self.jack_tokenizer.advance()
self.compile_term()
if symbol in self.BINARY_OPERATORS_TO_COMMAND:
self.vm_writer.write_arithmetic(
self.BINARY_OPERATORS_TO_COMMAND[symbol])
elif symbol == '*':
self.vm_writer.write_call('Math.multiply', 2)
elif symbol == '/':
self.vm_writer.write_call('Math.divide', 2)
def compile_term(self):
token_type = self.jack_tokenizer.token_type()
if token_type == 'IDENTIFIER':
name = self.jack_tokenizer.identifier()
self.jack_tokenizer.advance()
if self.jack_tokenizer.symbol(
) == '(' or self.jack_tokenizer.symbol() == '.':
self.compile_subroutine_call(name)
elif self.jack_tokenizer.symbol() == '[':
self.vm_writer.write_push(self.symbol_table.kind_of(name),
self.symbol_table.index_of(name))
self.jack_tokenizer.advance()
self.compile_expression()
self.jack_tokenizer.advance()
self.vm_writer.write_arithmetic('add')
self.vm_writer.write_pop('POINTER', 1)
self.vm_writer.write_push('THAT', 0)
else:
kind = self.symbol_table.kind_of(name)
idx = self.symbol_table.index_of(name)
self.vm_writer.write_push(kind, idx)
elif token_type == 'STRING_CONST':
string_const = self.jack_tokenizer.string_val()
self.vm_writer.write_push("CONST", len(string_const))
self.vm_writer.write_call("String.new", 1)
for char in string_const:
self.vm_writer.write_push('CONST', ord(char))
self.vm_writer.write_call("String.appendChar", 2)
self.jack_tokenizer.advance()
elif token_type == 'KEYWORD':
keyword = self.jack_tokenizer.key_word()
if keyword == 'true':
self.vm_writer.write_push('CONST', 1)
self.vm_writer.write_arithmetic('neg')
elif keyword == 'false' or keyword == 'null':
self.vm_writer.write_push('CONST', 0)
elif keyword == 'this':
self.vm_writer.write_push('POINTER', 0)
self.jack_tokenizer.advance()
elif token_type == 'SYMBOL':
if self.jack_tokenizer.symbol() == '(':
self.jack_tokenizer.advance()
self.compile_expression()
self.jack_tokenizer.advance()
elif self.jack_tokenizer.symbol(
) in CompilationEngine.UNARY_OPERATOR_SYMBOLS:
command = CompilationEngine.UNARY_OPERATORS_TO_COMMAND[
self.jack_tokenizer.symbol()]
self.jack_tokenizer.advance()
self.compile_term()
self.vm_writer.write_arithmetic(command)
elif token_type == 'INT_CONST':
self.vm_writer.write_push('CONST', self.jack_tokenizer.int_val())
self.jack_tokenizer.advance()
def compile_expression_list(self):
expression_count = 0
if self.jack_tokenizer.symbol() != ')':
self.compile_expression()
expression_count += 1
while self.jack_tokenizer.symbol() == ',':
self.jack_tokenizer.advance()
self.compile_expression()
expression_count += 1
return expression_count
