import collections
-IntegerLiteral = collections.namedtuple(
- 'IntegerLiteral',
+def _or_parser(*parsers):
+ def result_parser(index, tokens):
+ failure = (False, index, None)
+
+ for parser in parsers:
+ success, index, value = parser(index, tokens)
+
+ if success:
+ return (success, index, value)
+
+ return failure
+
+ return result_parser
+
+def _zero_or_more_parser(formatter, parser):
+ def result_parser(index, tokens):
+ values = []
+
+ while index < len(tokens):
+ success, index, value = parser(index, tokens)
+
+ if success:
+ values.append(value)
+ else:
+ break
+
+ return (True, index, formatter(values))
+
+ return result_parser
+
+FurIntegerLiteralExpression = collections.namedtuple(
+ 'FurIntegerLiteralExpression',
[
'value',
],
)
-StringLiteral = collections.namedtuple(
- 'StringLiteral',
+FurStringLiteralExpression = collections.namedtuple(
+ 'FurStringLiteralExpression',
[
'value',
],
)
-def _integer_literal_parser(index, tokens):
+FurAdditionExpression = collections.namedtuple(
+ 'FurAdditionExpression',
+ [
+ 'left',
+ 'right',
+ ],
+)
+
+FurSubtractionExpression = collections.namedtuple(
+ 'FurSubtractionExpression',
+ [
+ 'left',
+ 'right',
+ ],
+)
+
+FurMultiplicationExpression = collections.namedtuple(
+ 'FurMultiplicationExpression',
+ [
+ 'left',
+ 'right',
+ ],
+)
+
+FurIntegerDivisionExpression = collections.namedtuple(
+ 'FurIntegerDivisionExpression',
+ [
+ 'left',
+ 'right',
+ ],
+)
+
+FurModularDivisionExpression = collections.namedtuple(
+ 'FurModularDivisionExpression',
+ [
+ 'left',
+ 'right',
+ ],
+)
+
+def _integer_literal_expression_parser(index, tokens):
failure = (False, index, None)
if tokens[index].type != 'integer_literal':
value = int(tokens[index].match)
index += 1
- return True, index, IntegerLiteral(value=value)
+ return True, index, FurIntegerLiteralExpression(value=value)
-def _string_literal_parser(index, tokens):
+def _string_literal_expression_parser(index, tokens):
failure = (False, index, None)
if tokens[index].type != 'single_quoted_string_literal':
value = tokens[index].match[1:-1]
index += 1
- return True, index, StringLiteral(value=value)
+ return True, index, FurStringLiteralExpression(value=value)
+
+def _literal_level_expression_parser(index, tokens):
+ return _or_parser(
+ _function_call_expression_parser,
+ _integer_literal_expression_parser,
+ _string_literal_expression_parser,
+ )(index, tokens)
+
+def _multiplication_level_expression_parser(index, tokens):
+ failure = (False, index, None)
+
+ success, index, result = _literal_level_expression_parser(index, tokens)
-def _argument_parser(index, tokens):
+ if not success:
+ return failure
+
+ while success and index < len(tokens) and tokens[index].type == 'multiplication_level_operator':
+ success = False
+
+ if index + 1 < len(tokens):
+ success, try_index, value = _literal_level_expression_parser(index + 1, tokens)
+
+ if success:
+ result = {
+ '*': FurMultiplicationExpression,
+ '//': FurIntegerDivisionExpression,
+ '%': FurModularDivisionExpression,
+ }[tokens[index].match](left=result, right=value)
+ index = try_index
+
+ return True, index, result
+
+def _addition_level_expression_parser(index, tokens):
failure = (False, index, None)
- for parser in [_integer_literal_parser, _string_literal_parser]:
- success, index, value = parser(index, tokens)
+ success, index, result = _multiplication_level_expression_parser(index, tokens)
+
+ if not success:
+ return failure
+
+ while success and index < len(tokens) and tokens[index].type == 'addition_level_operator':
+ success = False
+
+ if index + 1 < len(tokens):
+ success, try_index, value = _multiplication_level_expression_parser(index + 1, tokens)
if success:
- return (success, index, value)
+ result = {
+ '+': FurAdditionExpression,
+ '-': FurSubtractionExpression,
+ }[tokens[index].match](left=result, right=value)
+ index = try_index
- return failure
+ return True, index, result
+def _comma_separated_list_parser(index, tokens):
+ failure = (False, index, None)
-FunctionCall = collections.namedtuple(
- 'FunctionCall',
+ 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',
'arguments',
],
)
-def _function_call_parser(index, tokens):
+FurProgram = collections.namedtuple(
+ 'FurProgram',
+ [
+ 'statement_list',
+ ],
+)
+
+def _function_call_expression_parser(index, tokens):
failure = (False, index, None)
if tokens[index].type != 'symbol':
return failure
index += 1
- success, index, argument = _argument_parser(index, tokens)
+ success, index, arguments = _comma_separated_list_parser(index, tokens)
if not success:
return failure
if tokens[index].type != 'close_parenthese':
- return failure
+ raise Exception('Expected ")", found "{}" on line {}'.format(
+ tokens[index].match,
+ tokens[index].line,
+ ))
index += 1
-
- return True, index, FunctionCall(name=name, arguments=(argument,))
+
+ return True, index, FurFunctionCallExpression(name=name, arguments=arguments)
+
+def _program_formatter(statement_list):
+ return FurProgram(statement_list=statement_list)
+
+_program_parser = _zero_or_more_parser(_program_formatter, _function_call_expression_parser)
def _parse(parser, tokens):
success, index, result = parser(0, tokens)
+ if index < len(tokens):
+ raise Exception('Unable to parse token {}'.format(tokens[index]))
+
if success:
return result
raise Exception('Unable to parse')
-
def parse(tokens):
- return _parse(_function_call_parser, tokens)
+ return _parse(_program_parser, tokens)
if __name__ == '__main__':
import unittest
import tokenization
- class StringLiteralParserTests(unittest.TestCase):
+ class FurStringLiteralExpressionParserTests(unittest.TestCase):
def test_parses_single_quoted_string_literal(self):
self.assertEqual(
- _string_literal_parser(0, tokenization.tokenize("'Hello, world'")),
+ _string_literal_expression_parser(0, tokenization.tokenize("'Hello, world'")),
(
True,
1,
- StringLiteral(value='Hello, world'),
+ FurStringLiteralExpression(value='Hello, world'),
),
)
- 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=(StringLiteral(value='Hello, world'),),
+ arguments=(FurStringLiteralExpression(value='Hello, world'),),
),
),
)