def compile_subroutine_dec(self):
while self.tokenizer.current_token in [CONSTRUCTOR, FUNCTION, METHOD]:
self.openNonTerminal(SUBROUTINE_DEC)
# eat subroutine type: method, function or constructor
self.eat(self.tokenizer.current_token)
# eat subroutine return type
if self.tokenizer.current_token != VOID and not self.is_valid_type(
self.tokenizer.current_token):
raise CompilationError(
"Expected valid subroutine return type or void but was " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
# eat subroutine name
if not lexical_elements.is_identifier(
self.tokenizer.current_token):
raise CompilationError(
"Expected valid subroutine name but was " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
# compile subroutine parameter list (possibly empty)
self.compile_parameter_list()
# compile subroutine body
self.compile_subroutine_body()
self.closeNonTerminal(SUBROUTINE_DEC)
def compile_subroutine_call(self):
# eat identifier
if not lexical_elements.is_identifier(self.tokenizer.current_token):
raise CompilationError(
"Expected valid identifier in subroutine call but found " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
if self.tokenizer.current_token == "(":
self.eat("(")
self.compile_expression_list()
self.eat(")")
elif self.tokenizer.current_token == ".":
self.eat(".")
# eat subroutine name
if not lexical_elements.is_identifier(
self.tokenizer.current_token):
raise CompilationError(
"Expected valid identifier in subroutine call but found " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
self.eat("(")
self.compile_expression_list()
self.eat(")")
else:
raise CompilationError(
"Expected '(' or '.' in subroutine call but found " +
self.tokenizer.current_token)
def eat_var_dec(self):
# eat var type
if not self.is_valid_type(self.tokenizer.current_token):
raise CompilationError("Expected valid var type but found " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
# eat var name
if not lexical_elements.is_identifier(self.tokenizer.current_token):
raise CompilationError("Expected valid var name but found " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
def eat(self, token):
current_token = self.tokenizer.current_token
if current_token != token:
raise CompilationError(
"Expected to find token '{0:}' but found '{1:}'".format(
token, current_token))
self.tokenizer.advance()
def compile_class(self):
self.tokenizer.advance()
self.openNonTerminal(CLASS)
# eat 'class' keyword
self.eat(CLASS)
# eat class name
if not lexical_elements.is_identifier(self.tokenizer.current_token):
raise CompilationError(
"Class name must be a valid identifier but was " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
# eat opening brace
self.eat("{")
# compile class variable declarations
self.compile_class_var_dec()
# compile class subroutines
self.compile_subroutine_dec()
# eat closing brace
self.eat("}")
self.closeNonTerminal(CLASS)
def eat(self, token):
current_token = self.tokenizer.current_token
if current_token != token:
raise CompilationError(
"Expected to find token '{0:}' but found '{1:}'".format(
token, current_token))
self.output_file.write("<{0:}> {1:} </{0:}>".format(
self.tokenizer.token_type(token),
self.tokenizer.get_token_value(current_token)) + "\n")
self.tokenizer.advance()
def eat_var_sequence(self):
self.eat_var_dec()
while self.tokenizer.current_token == ",":
self.eat(",")
if not lexical_elements.is_identifier(
self.tokenizer.current_token):
raise CompilationError(
"Expected valid variable name but was " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token) # eat varName
def compile_file(self, file_path):
print("Compiling", file_path, "...")
file_name = os.path.splitext(os.path.basename(file_path))[0]
dir_name = os.path.split(file_path)[0]
output_file_name = os.path.join(dir_name, file_name + "__.xml")
with open(output_file_name, "w") as output_file:
tokenizer = Tokenizer(file_path)
try:
compiler = CompilationEngine(tokenizer, output_file)
compiler.compile()
print("Compilation successful!", file_path, "=>",
output_file_name)
except CompilationError as err:
tokenizer.close()
raise CompilationError("ERROR: " + err.message)
def compile_let_statement(self):
self.openNonTerminal(LET_STATEMENT)
# eat 'let' keyword
self.eat(LET)
# eat variable name
if not lexical_elements.is_identifier(self.tokenizer.current_token):
raise CompilationError("Expected valid variable name but was " +
self.tokenizer.current_token)
self.eat(self.tokenizer.current_token)
# eat potential array indexing expression
if self.tokenizer.current_token == "[":
self.eat("[")
self.compile_expression()
self.eat("]")
self.eat("=")
self.compile_expression()
self.eat(";")
self.closeNonTerminal(LET_STATEMENT)