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Lexer: added support for for loops

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This commit is contained in:
weckyy702
2021-04-05 20:17:50 +02:00
parent bb0362ed10
commit 4592aa6725
1 changed files with 77 additions and 15 deletions
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92
interpreter/Lexer.py
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@@ -14,9 +14,6 @@ class Lexer:
self._token_index = 0
self._scopes: List[Function_scope] = []
self._current_scope = None
self._current_scoped_instruction = None
#in case the tokenizer finds valid tokens in the global scope, they will be saved here
self._global_instructions = []
@@ -44,12 +41,12 @@ class Lexer:
if self._is_function_def(line_tokens):
func_name, func_return_type, func_args = self._construct_function_header_from_tokens(line_tokens)
fs = Function_scope(func_name, func_return_type, func_args)
current_scope = Function_scope(func_name, func_return_type, func_args)
instructions = self._get_instructions_in_scope()
fs._add_instructions(instructions)
current_scope._add_instructions(instructions)
scopes.append(fs)
scopes.append(current_scope)
else:
#something was declared in global scope
@@ -58,7 +55,6 @@ class Lexer:
self.add_globals_to_scope_list(scopes)
return scopes
def _get_instructions_in_scope(self):
instructions = []
@@ -74,18 +70,21 @@ class Lexer:
if delimiter_token.type == Token_type.RIGHT_CURLY:
return instructions
raise JavaSyntaxError(f"Missing right curly!")
raise JavaSyntaxError(f"{self._peek(-1).location}: Missing right curly!")
def get_line_tokens(self):
def get_tokens_until(self, delimiter_types: List[Token_type]) -> List[Token]:
tokens = []
while token := self._consume():
tokens.append(token)
if token.type in [Token_type.SEMICOLON, Token_type.LEFT_CURLY, Token_type.RIGHT_CURLY]:
if token.type in delimiter_types:
break
return tokens
def get_line_tokens(self):
return self.get_tokens_until([Token_type.SEMICOLON, Token_type.LEFT_CURLY, Token_type.RIGHT_CURLY])
def add_globals_to_scope_list(self, scope_list: List[Function_scope]):
@@ -212,14 +211,30 @@ class Lexer:
def _handle_for_construct(self, tokens: List[Token]):
#TODO: change that
logging.debug("Found for construct")
tokens.extend(self.get_line_tokens())
tokens.extend(self.get_line_tokens())
tokens.extend(self.get_tokens_until([Token_type.LEFT_CURLY]))
_ensure_correct_for_structure(tokens)
variable_tokens, condition_tokens, increment_tokens = _get_for_arguments_from_tokens(tokens[2:])
variable_str = ""
if len(variable_tokens) > 1: #if we got more than just a semicolon
variable_str = self._construct_variable_def_from_tokens(variable_tokens)
condition_str = "true"
if condition_tokens:
condition_str = self._construct_source_line_from_tokens(condition_tokens)
increment_instruction = None
if increment_tokens:
increment_instruction = generic_instruction(self._construct_source_line_from_tokens(increment_tokens))
loop_instructions = self._get_instructions_in_scope()
loop_instructions.append(generic_instruction("increment"))
if increment_instruction:
loop_instructions.append(increment_instruction)
return for_instruction("for_instruction", loop_instructions)
return for_instruction(variable_str, condition_str, loop_instructions)
def _handle_type_name_construct(self, tokens: List[Token]):
logging.debug("Found Type name construct")
@@ -299,6 +314,19 @@ def _ensure_correct_do_while_structure_part_2(tokens: List[Token]):
if tokens[-2].type != Token_type.RIGTH_PAREN:
raise JavaSyntaxError(f"{tokens[-2].location}: Illegal token after do-while condition! Expected RIGHT_PAREN, got {str(tokens[-2].type)}")
def _ensure_correct_for_structure(tokens: List[Token]):
#for structure: for(...?;...?;...?) {
if len(tokens) < 6:
raise JavaSyntaxError(f"{tokens[0].location}: Illf-formed for loop construct! Expected at least 6 tokens, got {len(tokens)}")
if tokens[-1].type != Token_type.LEFT_CURLY:
raise JavaSyntaxError(f"{tokens[-1].location}: Ill-formed for loop construct! Expected last token to be LEFT_CURLY, got {str(tokens[-1].type)}")
if tokens[1].type != Token_type.LEFT_PAREN:
raise JavaSyntaxError(f"{tokens[1].location}: Illegal token after for token! Expected LEFT_PAREN, got {str(tokens[1].type)}")
if tokens[-2].type != Token_type.RIGTH_PAREN:
raise JavaSyntaxError(f"{tokens[-2].location}: Illegal token after for loop increment! Expected RIGHT_PAREN, got {str(tokens[-2].type)}")
if ( semicolon_count := tokens.count(Token(Token_type.SEMICOLON)) ) != 2:
raise JavaSyntaxError(f"Ill-formed for loop construct! Expected exactly 2 SEMICOLON tokens, got {semicolon_count}")
def _get_function_argument_list_from_tokens(tokens: List[Token]) -> List[str]:
@@ -328,4 +356,38 @@ def _get_seperated_token_list(tokens: List[Token], seperator_types: List[Token_t
token_segments.append(tokens_in_segment)
return token_segments
return token_segments
def _get_for_arguments_from_tokens(tokens: List[Token]) -> Tuple[List[Token], List[Token], List[Token]]:
variable_tokens = []
condition_tokens = []
increment_tokens = []
token_index = 0
while True:
token = tokens[token_index]
token_index += 1
variable_tokens.append(token)
if token.type == Token_type.SEMICOLON:
break
while True:
token = tokens[token_index]
token_index += 1
if token.type == Token_type.SEMICOLON:
break
condition_tokens.append(token)
while True:
token = tokens[token_index]
token_index += 1
if token.type == Token_type.LEFT_CURLY:
break
increment_tokens.append(token)
return variable_tokens, condition_tokens, increment_tokens[:-2]