X-Git-Url: https://code.kerkeslager.com/?p=fur;a=blobdiff_plain;f=parsing.py;h=20ac3761252a577523034493d347383c4b9fcdd4;hp=a543819891217a1b6297669e48ec4289738ab236;hb=HEAD;hpb=777a46709a4353837a34df7fc0f7d9f3d47902a7 diff --git a/parsing.py b/parsing.py index a543819..20ac376 100644 --- a/parsing.py +++ b/parsing.py @@ -43,6 +43,14 @@ FurIntegerLiteralExpression = collections.namedtuple( ], ) +FurLambdaExpression = collections.namedtuple( + 'FurLambdaExpression', + ( + 'argument_name_list', + 'statement_list', + ), +) + FurStringLiteralExpression = collections.namedtuple( 'FurStringLiteralExpression', [ @@ -53,13 +61,15 @@ FurStringLiteralExpression = collections.namedtuple( FurSymbolExpression = collections.namedtuple( 'FurSymbolExpression', [ - 'value', + 'metadata', + 'symbol', ], ) FurNegationExpression = collections.namedtuple( 'FurNegationExpression', [ + 'metadata', 'value', ], ) @@ -67,6 +77,7 @@ FurNegationExpression = collections.namedtuple( FurInfixExpression = collections.namedtuple( 'FurInfixExpression', [ + 'metadata', 'order', 'operator', 'left', @@ -74,6 +85,37 @@ FurInfixExpression = collections.namedtuple( ], ) +FurListLiteralExpression = collections.namedtuple( + 'FurListLiteralExpression', + [ + 'item_expression_list', + ], +) + +FurIfExpression = collections.namedtuple( + 'FurIfExpression', + [ + 'condition_expression', + 'if_statement_list', + 'else_statement_list', + ], +) + +FurSymbolExpressionPair = collections.namedtuple( + 'FurSymbolExpressionPair', + [ + 'symbol', + 'expression', + ], +) + +FurStructureLiteralExpression = collections.namedtuple( + 'FurStructureLiteralExpression', + [ + 'fields', + ], +) + def _integer_literal_expression_parser(index, tokens): failure = (False, index, None) @@ -85,6 +127,9 @@ def _integer_literal_expression_parser(index, tokens): return True, index, FurIntegerLiteralExpression(integer=value) def _string_literal_expression_parser(index, tokens): + if tokens[index].type == 'double_quoted_string_literal': + return (True, index + 1, FurStringLiteralExpression(string=tokens[index].match[1:-1])) + if tokens[index].type == 'single_quoted_string_literal': return (True, index + 1, FurStringLiteralExpression(string=tokens[index].match[1:-1])) @@ -92,15 +137,22 @@ def _string_literal_expression_parser(index, tokens): def _symbol_expression_parser(index, tokens): if tokens[index].type == 'symbol': - return (True, index + 1, FurSymbolExpression(value=tokens[index].match)) + return ( + True, + index + 1, + FurSymbolExpression( + metadata=tokens[index].metadata, + symbol=tokens[index].match, + ), + ) return (False, index, None) -def _parenthese_wrapped_parser(internal_parser): +def _wrapped_parser(open_token, close_token, internal_parser): def result_parser(index, tokens): failure = (False, index, None) - if tokens[index].type == 'open_parenthese': + if tokens[index].type == open_token: index += 1 else: return failure @@ -109,10 +161,11 @@ def _parenthese_wrapped_parser(internal_parser): if not success: return failure - if tokens[index].type == 'close_parenthese': + if tokens[index].type == close_token: index += 1 else: - raise Exception('Expected ")" on line {}, found "{}"'.format( + # TODO Put the actual expected character in the error message + raise Exception('Expected closing token on line {}, found "{}"'.format( tokens[index].line, tokens[index].match, )) @@ -121,30 +174,154 @@ def _parenthese_wrapped_parser(internal_parser): return result_parser +def _bracket_wrapped_parser(internal_parser): + return _wrapped_parser('open_bracket', 'close_bracket', internal_parser) + +def _parenthese_wrapped_parser(internal_parser): + return _wrapped_parser('open_parenthese', 'close_parenthese', internal_parser) + def _parenthesized_expression_parser(index, tokens): return _parenthese_wrapped_parser(_expression_parser)(index, tokens) -def _negation_expression_parser(index, tokens): +def symbol_expression_pair_parser(index, tokens): failure = (False, index, None) - if tokens[index].match != '-': + if tokens[index].type == 'symbol': + symbol = tokens[index].match + index += 1 + else: return failure - success, index, value = _literal_level_expression_parser(index + 1, tokens) + if tokens[index].type == 'colon': + index += 1 + else: + return failure + + success, index, expression = _expression_parser(index, tokens) if not success: + raise Exception() + + return ( + True, + index, + FurSymbolExpressionPair( + symbol=symbol, + expression=expression, + ), + ) + +def _structure_literal_parser(index, tokens): + success, index, result = _parenthese_wrapped_parser(_comma_separated_list_parser(symbol_expression_pair_parser))(index, tokens) + return ( + success, + index, + FurStructureLiteralExpression( + fields=result, + ), + ) + +def _lambda_expression_parser(index, tokens): + failure = (False, index, None) + + if tokens[index].type == 'keyword' and tokens[index].match == 'lambda': + index += 1 + else: return failure - return (True, index, FurNegationExpression(value=value)) + if tokens[index].type == 'open_parenthese': + index += 1 + else: + raise Exception('Expected "(", found "{}" on line {}'.format( + tokens[index].match, + tokens[index].metadata.line, + )) + + success, index, argument_name_list = _comma_separated_list_parser(_symbol_expression_parser)( + index, + tokens, + ) + + if tokens[index].type == 'close_parenthese': + index += 1 + else: + raise Exception('Expected ")", found "{}" on line {}'.format( + tokens[index].match, + tokens[index].line, + )) + + if tokens[index].match == 'do': + index += 1 + else: + return failure + + success, index, statement_list = _zero_or_more_parser(tuple, _statement_parser)(index, tokens) + + _, index, _ = consume_newlines(index, tokens) + + if tokens[index].type == 'keyword' and tokens[index].match == 'end': + index += 1 + else: + return failure + + return True, index, FurLambdaExpression( + argument_name_list=tuple(an.symbol for an in argument_name_list), + statement_list=statement_list, + ) + + + +def _list_literal_expression_parser(index, tokens): + failure = (False, index, None) + + success, index, item_expression_list = _bracket_wrapped_parser(_comma_separated_expression_list_parser)(index, tokens) + + if success: + return success, index, FurListLiteralExpression( + item_expression_list=item_expression_list, + ) + else: + return failure def _literal_level_expression_parser(index, tokens): return _or_parser( - _negation_expression_parser, + _list_item_expression_parser, _function_call_expression_parser, _parenthesized_expression_parser, _integer_literal_expression_parser, _string_literal_expression_parser, + _list_literal_expression_parser, + _lambda_expression_parser, _symbol_expression_parser, + _structure_literal_parser, + )(index, tokens) + +def _dot_expression_parser(index, tokens): + return _left_recursive_infix_operator_parser( + lambda token: token.type == 'period', + _literal_level_expression_parser, + 'dot_level', + )(index, tokens) + +def _negation_expression_parser(index, tokens): + failure = (False, index, None) + + if tokens[index].match != '-': + return failure + + metadata = tokens[index].metadata + + success, index, value = _dot_expression_parser(index + 1, tokens) + + if not success: + return failure + + return (True, index, FurNegationExpression(metadata=metadata, value=value)) + +def _negation_level_expression_parser(index, tokens): + return _or_parser( + _dot_expression_parser, + _negation_expression_parser, )(index, tokens) def _left_recursive_infix_operator_parser(operator_token_matcher, operand_parser, order): @@ -164,6 +341,7 @@ def _left_recursive_infix_operator_parser(operator_token_matcher, operand_parser if success: result = FurInfixExpression( + metadata=tokens[index].metadata, order=order, operator=tokens[index].match, left=result, @@ -178,7 +356,7 @@ def _left_recursive_infix_operator_parser(operator_token_matcher, operand_parser def _multiplication_level_expression_parser(index, tokens): return _left_recursive_infix_operator_parser( lambda token: token.type == 'multiplication_level_operator', - _literal_level_expression_parser, + _negation_level_expression_parser, 'multiplication_level', )(index, tokens) @@ -216,6 +394,8 @@ def _comma_separated_list_parser(subparser): items = [] + _, index, _ = consume_newlines(index, tokens) + success, index, item = subparser(index, tokens) if success: @@ -224,10 +404,13 @@ def _comma_separated_list_parser(subparser): return (True, start_index, ()) while success and index < len(tokens) and tokens[index].type == 'comma': + index += 1 success = False - if index + 1 < len(tokens): - success, try_index, item = subparser(index + 1, tokens) + _, index, _ = consume_newlines(index, tokens) + + if index < len(tokens): + success, try_index, item = subparser(index, tokens) if success: items.append(item) @@ -240,9 +423,19 @@ def _comma_separated_list_parser(subparser): def _comma_separated_expression_list_parser(index, tokens): return _comma_separated_list_parser(_expression_parser)(index, tokens) +FurListItemExpression = collections.namedtuple( + 'FurListItemExpression', + [ + 'list_expression', + 'metadata', + 'index_expression', + ], +) + FurFunctionCallExpression = collections.namedtuple( 'FurFunctionCallExpression', [ + 'metadata', 'function', 'arguments', ], @@ -279,6 +472,47 @@ FurProgram = collections.namedtuple( ], ) +def _list_item_expression_parser(index, tokens): + failure = (False, index, None) + + # We have to be careful what expressions we add here. Otherwise expressions + # like "a + b[0]" become ambiguous to the parser. + success, index, list_expression = _or_parser( + _symbol_expression_parser, + _parenthesized_expression_parser, + )(index, tokens) + + if not success: + return failure + + metadata = tokens[index].metadata + + success, index, index_expression = _bracket_wrapped_parser(_expression_parser)( + index, + tokens, + ) + + if not success: + return failure + + while success and index < len(tokens): + # "list_expression" is actually the full list item expression if the next parse attempt doesn't succeed + # We can't give this a better name without a bunch of checks, however. + list_expression = FurListItemExpression( + list_expression=list_expression, + metadata=metadata, + index_expression=index_expression, + ) + + metadata = tokens[index].metadata + + success, index, index_expression = _bracket_wrapped_parser(_expression_parser)( + index, + tokens, + ) + + return True, index, list_expression + def _function_call_expression_parser(index, tokens): failure = (False, index, None) @@ -292,6 +526,8 @@ def _function_call_expression_parser(index, tokens): if not success: return failure + metadata = tokens[index].metadata + success, index, arguments = _parenthese_wrapped_parser(_comma_separated_expression_list_parser)( index, tokens, @@ -304,10 +540,13 @@ def _function_call_expression_parser(index, tokens): # "function" is actually the full function call if the next parse attempt doesn't succeed # We can't give this a better name without a bunch of checks, however. function = FurFunctionCallExpression( + metadata=metadata, function=function, arguments=arguments, ) + metadata = tokens[index].metadata + success, index, arguments = _parenthese_wrapped_parser(_comma_separated_expression_list_parser)( index, tokens, @@ -315,7 +554,54 @@ def _function_call_expression_parser(index, tokens): return True, index, function -_expression_parser = _or_level_expression_parser +def _if_expression_parser(index, tokens): + failure = (False, index, None) + + if tokens[index].match == 'if': + index += 1 + else: + return failure + + success, index, condition_expression = _or_level_expression_parser(index, tokens) + + if not success: + raise Exception('Expected condition after "if" on line {}'.format(tokens[index].line)) + + if tokens[index].match == 'do': + index += 1 + else: + raise Exception('Expected "do" after "if" on line {}'.format(tokens[index].line)) + + + success, index, if_statement_list = _zero_or_more_parser(tuple, _statement_parser)(index, tokens) + _, index, _ = consume_newlines(index, tokens) + + if tokens[index].match == 'else': + index += 1 + success, index, else_statement_list = _zero_or_more_parser(tuple, _statement_parser)(index, tokens) + _, index, _ = consume_newlines(index, tokens) + else: + else_statement_list = () + + if tokens[index].match == 'end': + index += 1 + else: + raise Exception('Expected "end" after "if" on line {}'.format(tokens[index].line)) + + return ( + True, + index, + FurIfExpression( + condition_expression=condition_expression, + if_statement_list=if_statement_list, + else_statement_list=else_statement_list, + ), + ) + +_expression_parser = _or_parser( + _or_level_expression_parser, + _if_expression_parser, # This should always be at the top level +) def _expression_statement_parser(index, tokens): failure = (False, index, None) @@ -334,7 +620,7 @@ def _assignment_statement_parser(index, tokens): if tokens[index].type == 'symbol': target = tokens[index].match - target_assignment_line = tokens[index].line + target_assignment_line = tokens[index].metadata.line index += 1 else: @@ -399,7 +685,7 @@ def _function_definition_statement_parser(index, tokens): tokens[index].line, )) - if tokens[index].type == 'symbol' and tokens[index].match == 'do': + if tokens[index].match == 'do': index += 1 else: return failure @@ -415,7 +701,7 @@ def _function_definition_statement_parser(index, tokens): return True, index, FurFunctionDefinitionStatement( name=name, - argument_name_list=tuple(an.value for an in argument_name_list), + argument_name_list=tuple(an.symbol for an in argument_name_list), statement_list=statement_list, )