FurIntegerLiteralExpression = collections.namedtuple(
'FurIntegerLiteralExpression',
[
- 'value',
+ 'integer',
],
)
FurStringLiteralExpression = collections.namedtuple(
'FurStringLiteralExpression',
[
- 'value',
+ 'string',
],
)
FurSymbolExpression = collections.namedtuple(
'FurSymbolExpression',
[
- 'value',
+ 'symbol',
],
)
],
)
-FurParenthesizedExpression = collections.namedtuple(
- 'FurParenthesizedExpression',
- [
- 'internal',
- ],
-)
-
FurInfixExpression = collections.namedtuple(
'FurInfixExpression',
[
value = int(tokens[index].match)
index += 1
- return True, index, FurIntegerLiteralExpression(value=value)
+ return True, index, FurIntegerLiteralExpression(integer=value)
def _string_literal_expression_parser(index, tokens):
if tokens[index].type == 'single_quoted_string_literal':
- return (True, index + 1, FurStringLiteralExpression(value=tokens[index].match[1:-1]))
+ return (True, index + 1, FurStringLiteralExpression(string=tokens[index].match[1:-1]))
return (False, index, None)
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(symbol=tokens[index].match))
return (False, index, None)
-def _parenthesized_expression_parser(index, tokens):
- failure = (False, index, None)
+def _parenthese_wrapped_parser(internal_parser):
+ def result_parser(index, tokens):
+ failure = (False, index, None)
- if tokens[index].type == 'open_parenthese':
- index += 1
- else:
- return failure
+ if tokens[index].type == 'open_parenthese':
+ index += 1
+ else:
+ return failure
- success, index, internal = _expression_parser(index, tokens)
- if not success:
- return failure
+ success, index, internal = internal_parser(index, tokens)
+ if not success:
+ return failure
- if tokens[index].type == 'close_parenthese':
- index += 1
- else:
- raise Exception('Expected ")" on line {}, found "{}"'.format(
- tokens[index].line,
- tokens[index].match,
- ))
+ if tokens[index].type == 'close_parenthese':
+ index += 1
+ else:
+ raise Exception('Expected ")" on line {}, found "{}"'.format(
+ tokens[index].line,
+ tokens[index].match,
+ ))
- return True, index, FurParenthesizedExpression(internal=internal)
+ return True, index, internal
+
+ return result_parser
+
+def _parenthesized_expression_parser(index, tokens):
+ return _parenthese_wrapped_parser(_expression_parser)(index, tokens)
def _negation_expression_parser(index, tokens):
failure = (False, index, None)
'or_level',
)(index, tokens)
-def _comma_separated_list_parser(index, tokens):
- failure = (False, index, None)
+def _comma_separated_list_parser(subparser):
+ def result_parser(index, tokens):
+ start_index = index
- expressions = []
+ items = []
- success, index, expression = _expression_parser(index, tokens)
+ success, index, item = subparser(index, tokens)
- if success:
- expressions.append(expression)
- else:
- return failure
+ if success:
+ items.append(item)
+ else:
+ return (True, start_index, ())
- while success and index < len(tokens) and tokens[index].type == 'comma':
- success = False
+ while success and index < len(tokens) and tokens[index].type == 'comma':
+ success = False
- if index + 1 < len(tokens):
- success, try_index, expression = _expression_parser(index + 1, tokens)
+ if index + 1 < len(tokens):
+ success, try_index, item = subparser(index + 1, tokens)
- if success:
- expressions.append(expression)
- index = try_index
+ if success:
+ items.append(item)
+ index = try_index
+
+ return True, index, tuple(items)
- return True, index, tuple(expressions)
+ return result_parser
+def _comma_separated_expression_list_parser(index, tokens):
+ return _comma_separated_list_parser(_expression_parser)(index, tokens)
FurFunctionCallExpression = collections.namedtuple(
'FurFunctionCallExpression',
],
)
+FurFunctionDefinitionStatement = collections.namedtuple(
+ 'FurFunctionDefinitionStatement',
+ [
+ 'name',
+ 'argument_name_list',
+ 'statement_list',
+ ],
+)
+
FurProgram = collections.namedtuple(
'FurProgram',
[
)
def _function_call_expression_parser(index, tokens):
- # TODO Use a FurSymbolExpression for the name
failure = (False, index, None)
- success, index, function = _symbol_expression_parser(index, tokens)
+ # We have to be careful what expressions we add here. Otherwise expressions
+ # like "a + b()" become ambiguous to the parser.
+ success, index, function = _or_parser(
+ _symbol_expression_parser,
+ _parenthesized_expression_parser,
+ )(index, tokens)
if not success:
return failure
- if tokens[index].type != 'open_parenthese':
- return failure
- index += 1
-
- success, index, arguments = _comma_separated_list_parser(index, tokens)
+ success, index, arguments = _parenthese_wrapped_parser(_comma_separated_expression_list_parser)(
+ index,
+ tokens,
+ )
if not success:
return failure
- if tokens[index].type != 'close_parenthese':
- raise Exception('Expected ")", found "{}" on line {}'.format(
- tokens[index].match,
- tokens[index].line,
- ))
- index += 1
+ while success and index < len(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(
+ function=function,
+ arguments=arguments,
+ )
- return True, index, FurFunctionCallExpression(function=function, arguments=arguments)
+ success, index, arguments = _parenthese_wrapped_parser(_comma_separated_expression_list_parser)(
+ index,
+ tokens,
+ )
+
+ return True, index, function
_expression_parser = _or_level_expression_parser
return (True, index, FurExpressionStatement(expression=expression))
+BUILTINS = {'print', 'pow'}
+
def _assignment_statement_parser(index, tokens):
- # TODO Use a FurSymbolExpression for the target? Maybe this is actually not a good idea
failure = (False, index, None)
- if tokens[index].type != 'symbol':
+ if tokens[index].type == 'symbol':
+ target = tokens[index].match
+ target_assignment_line = tokens[index].line
+
+ index += 1
+ else:
return failure
- target = tokens[index].match
- index += 1
- if tokens[index].type != 'assignment_operator':
+
+ if tokens[index].type == 'assignment_operator':
+ if target in BUILTINS:
+ raise Exception(
+ 'Trying to assign to builtin "{}" on line {}'.format(target, target_assignment_line),
+ )
+ assignment_operator_index = index
+ else:
return failure
- assignment_operator_index = index
success, index, expression = _expression_parser(index + 1, tokens)
return True, index, FurAssignmentStatement(target=target, expression=expression)
+def _function_definition_statement_parser(index, tokens):
+ failure = (False, index, None)
+
+ if tokens[index].type == 'keyword' and tokens[index].match == 'def':
+ index += 1
+ else:
+ return failure
+
+ if tokens[index].type == 'symbol':
+ name = tokens[index].match
+ index += 1
+ else:
+ raise Exception('Expected function name, found "{}" on line {}'.format(
+ tokens[index].match,
+ tokens[index].line,
+ ))
+
+ if tokens[index].type == 'open_parenthese':
+ index += 1
+ else:
+ raise Exception('Expected "(", found "{}" on line {}'.format(
+ tokens[index].match,
+ tokens[index].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].type == 'symbol' and 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, FurFunctionDefinitionStatement(
+ name=name,
+ argument_name_list=tuple(an.symbol for an in argument_name_list),
+ statement_list=statement_list,
+ )
+
def _statement_parser(index, tokens):
_, index, _ = consume_newlines(index, tokens)
return _or_parser(
_assignment_statement_parser,
_expression_statement_parser,
+ _function_definition_statement_parser,
)(index, tokens)
def _program_formatter(statement_list):
(
True,
1,
- FurStringLiteralExpression(value='Hello, world'),
+ FurStringLiteralExpression(string='Hello, world'),
),
)
4,
FurFunctionCallExpression(
name='print',
- arguments=(FurStringLiteralExpression(value='Hello, world'),),
+ arguments=(FurStringLiteralExpression(string='Hello, world'),),
),
),
)
projects / fur / blobdiff