| from __future__ import absolute_import, print_function |
|
|
| import sys |
| from unittest import TestCase, main |
|
|
| from functools import partial |
| from lark.tree import Tree |
| from lark.tools import standalone |
|
|
| try: |
| from StringIO import StringIO |
| except ImportError: |
| from io import StringIO |
|
|
|
|
|
|
|
|
| class TestStandalone(TestCase): |
| def setUp(self): |
| pass |
|
|
| def _create_standalone(self, grammar): |
| code_buf = StringIO() |
| pr = partial(print, file=code_buf) |
| standalone.main(StringIO(grammar), 'start', print=pr) |
| code = code_buf.getvalue() |
|
|
| context = {'__doc__': None} |
| exec(code, context) |
| return context |
|
|
| def test_simple(self): |
| grammar = """ |
| start: NUMBER WORD |
| |
| %import common.NUMBER |
| %import common.WORD |
| %import common.WS |
| %ignore WS |
| |
| """ |
|
|
| context = self._create_standalone(grammar) |
|
|
| _Lark = context['Lark_StandAlone'] |
| l = _Lark() |
| x = l.parse('12 elephants') |
| self.assertEqual(x.children, ['12', 'elephants']) |
| x = l.parse('16 candles') |
| self.assertEqual(x.children, ['16', 'candles']) |
|
|
| self.assertRaises(context['UnexpectedToken'], l.parse, 'twelve monkeys') |
| self.assertRaises(context['UnexpectedToken'], l.parse, 'twelve') |
| self.assertRaises(context['UnexpectedCharacters'], l.parse, '$ talks') |
|
|
| def test_contextual(self): |
| grammar = """ |
| start: a b |
| a: "A" "B" |
| b: "AB" |
| """ |
|
|
| context = self._create_standalone(grammar) |
|
|
| _Lark = context['Lark_StandAlone'] |
| l = _Lark() |
| x = l.parse('ABAB') |
|
|
| class T(context['Transformer']): |
| def a(self, items): |
| return 'a' |
| def b(self, items): |
| return 'b' |
| start = list |
|
|
| x = T().transform(x) |
| self.assertEqual(x, ['a', 'b']) |
|
|
| l2 = _Lark(transformer=T()) |
| x = l2.parse('ABAB') |
| self.assertEqual(x, ['a', 'b']) |
|
|
| def test_postlex(self): |
| from lark.indenter import Indenter |
| class MyIndenter(Indenter): |
| NL_type = '_NEWLINE' |
| OPEN_PAREN_types = ['LPAR', 'LSQB', 'LBRACE'] |
| CLOSE_PAREN_types = ['RPAR', 'RSQB', 'RBRACE'] |
| INDENT_type = '_INDENT' |
| DEDENT_type = '_DEDENT' |
| tab_len = 8 |
|
|
| grammar = r""" |
| start: "(" ")" _NEWLINE |
| _NEWLINE: /\n/ |
| """ |
|
|
| context = self._create_standalone(grammar) |
| _Lark = context['Lark_StandAlone'] |
|
|
| l = _Lark(postlex=MyIndenter()) |
| x = l.parse('()\n') |
| self.assertEqual(x, Tree('start', [])) |
| l = _Lark(postlex=MyIndenter()) |
| x = l.parse('(\n)\n') |
| self.assertEqual(x, Tree('start', [])) |
|
|
| def test_transformer(self): |
| grammar = r""" |
| start: some_rule "(" SOME_TERMINAL ")" |
| some_rule: SOME_TERMINAL |
| SOME_TERMINAL: /[A-Za-z_][A-Za-z0-9_]*/ |
| """ |
| context = self._create_standalone(grammar) |
| _Lark = context["Lark_StandAlone"] |
|
|
| _Token = context["Token"] |
| _Tree = context["Tree"] |
|
|
| class MyTransformer(context["Transformer"]): |
| def SOME_TERMINAL(self, token): |
| return _Token("SOME_TERMINAL", "token is transformed") |
|
|
| def some_rule(self, children): |
| return _Tree("rule_is_transformed", []) |
|
|
| parser = _Lark(transformer=MyTransformer()) |
| self.assertEqual( |
| parser.parse("FOO(BAR)"), |
| _Tree("start", [ |
| _Tree("rule_is_transformed", []), |
| _Token("SOME_TERMINAL", "token is transformed") |
| ]) |
| ) |
|
|
|
|
| if __name__ == '__main__': |
| main() |
|
|
