],
)
+FurSymbolExpression = collections.namedtuple(
+ 'FurSymbolExpression',
+ [
+ 'value',
+ ],
+)
+
+FurNegationExpression = collections.namedtuple(
+ 'FurNegationExpression',
+ [
+ 'value',
+ ],
+)
+
FurAdditionExpression = collections.namedtuple(
'FurAdditionExpression',
[
return True, index, FurIntegerLiteralExpression(value=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 (False, index, None)
+
+def _symbol_expression_parser(index, tokens):
+ if tokens[index].type == 'symbol':
+ return (True, index + 1, FurSymbolExpression(value=tokens[index].match))
+
+ return (False, index, None)
+
+def _negation_expression_parser(index, tokens):
failure = (False, index, None)
- if tokens[index].type != 'single_quoted_string_literal':
+ if tokens[index].match != '-':
return failure
- value = tokens[index].match[1:-1]
- index += 1
- return True, index, FurStringLiteralExpression(value=value)
+ success, index, value = _literal_level_expression_parser(index + 1, tokens)
+
+ if not success:
+ return failure
+
+ return (True, index, FurNegationExpression(value=value))
def _literal_level_expression_parser(index, tokens):
return _or_parser(
+ _negation_expression_parser,
+ _function_call_expression_parser,
_integer_literal_expression_parser,
_string_literal_expression_parser,
+ _symbol_expression_parser,
)(index, tokens)
def _multiplication_level_expression_parser(index, tokens):
return True, index, result
-FunctionCall = collections.namedtuple(
- 'FunctionCall',
+def _comma_separated_list_parser(index, tokens):
+ failure = (False, index, None)
+
+ expressions = []
+
+ success, index, expression = _addition_level_expression_parser(index, tokens)
+
+ if success:
+ expressions.append(expression)
+ else:
+ return failure
+
+ while success and index < len(tokens) and tokens[index].type == 'comma':
+ success = False
+
+ if index + 1 < len(tokens):
+ success, try_index, expression = _addition_level_expression_parser(index + 1, tokens)
+
+ if success:
+ expressions.append(expression)
+ index = try_index
+
+ return True, index, tuple(expressions)
+
+
+FurFunctionCallExpression = collections.namedtuple(
+ 'FurFunctionCallExpression',
[
- 'name',
+ 'function',
'arguments',
],
)
+FurAssignmentStatement = collections.namedtuple(
+ 'FurAssignmentStatement',
+ [
+ 'target',
+ 'expression',
+ ],
+)
+
FurProgram = collections.namedtuple(
'FurProgram',
[
],
)
-def _function_call_parser(index, tokens):
+def _function_call_expression_parser(index, tokens):
+ # TODO Use a FurSymbolExpression for the name
failure = (False, index, None)
- if tokens[index].type != 'symbol':
+ success, index, function = _symbol_expression_parser(index, tokens)
+
+ if not success:
return failure
- name = tokens[index].match
- index += 1
if tokens[index].type != 'open_parenthese':
return failure
index += 1
- success, index, argument = _addition_level_expression_parser(index, tokens)
+ success, index, arguments = _comma_separated_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
+
+ return True, index, FurFunctionCallExpression(function=function, arguments=arguments)
+
+_expression_parser = _multiplication_level_expression_parser
+
+def _assignment_statement_parser(index, tokens):
+ # TODO Use a FurSymbolExpression for the target
+ failure = (False, index, None)
+
+ if tokens[index].type != 'symbol':
return failure
+ target = tokens[index].match
index += 1
- return True, index, FunctionCall(name=name, arguments=(argument,))
+ if tokens[index].type != 'assignment_operator':
+ return failure
+ assignment_operator_index = index
+
+ success, index, expression = _expression_parser(index + 1, tokens)
+
+ if not success:
+ raise Exception(
+ 'Expected expression after assignment operator on line {}'.format(
+ tokens[assignment_operator_index].line
+ )
+ )
+
+ return True, index, FurAssignmentStatement(target=target, expression=expression)
+
+def _statement_parser(index, tokens):
+ return _or_parser(
+ _assignment_statement_parser,
+ _expression_parser,
+ )(index, tokens)
def _program_formatter(statement_list):
return FurProgram(statement_list=statement_list)
-_program_parser = _zero_or_more_parser(_program_formatter, _function_call_parser)
+_program_parser = _zero_or_more_parser(_program_formatter, _statement_parser)
def _parse(parser, tokens):
success, index, result = parser(0, tokens)
raise Exception('Unable to parse')
-
def parse(tokens):
return _parse(_program_parser, tokens)
),
)
- class FunctionCallParserTests(unittest.TestCase):
+ class FurFunctionCallExpressionParserTests(unittest.TestCase):
def test_parses_function_with_string_literal_argument(self):
self.assertEqual(
- _function_call_parser(0, tokenization.tokenize("print('Hello, world')")),
+ _function_call_expression_parser(0, tokenization.tokenize("print('Hello, world')")),
(
True,
4,
- FunctionCall(
+ FurFunctionCallExpression(
name='print',
arguments=(FurStringLiteralExpression(value='Hello, world'),),
),