File size: 3,773 Bytes
dee9fba | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 | 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()
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