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# Copyright (c) 2017-2026 Juancarlo Añez (apalala@gmail.com)
# SPDX-License-Identifier: BSD-4-Clause
from __future__ import annotations
import json
import tempfile
import unittest
from pathlib import Path
import tatsu
from tatsu.parser import TatSuBuffer
from tatsu.util import asjson, eval_escapes, trim
class MockIncludeBuffer(TatSuBuffer):
def get_include(self, source, filename):
return f'\nINCLUDED "{filename}"\n', filename
class ParsingTests(unittest.TestCase):
def test_include(self):
text = """\
first
#include :: "something"
last\
"""
buf = MockIncludeBuffer(trim(text))
self.assertEqual('first\n\nINCLUDED "something"\nlast', buf.text)
def test_multiple_include(self):
text = """\
first
#include :: "something"
#include :: "anotherthing"
last\
"""
buf = MockIncludeBuffer(trim(text))
self.assertEqual(
'first\n\nINCLUDED "something"\n\nINCLUDED "anotherthing"\nlast',
buf.text,
)
def test_real_include(self):
_, include_a = tempfile.mkstemp(suffix='.tatsu', prefix='include_')
_, include_b = tempfile.mkstemp(suffix='.tatsu', prefix='include_')
grammar = """\
#include :: "{include_a}"
#include :: "{include_b}"
start = a b;"""
Path(include_a).write_text("a = 'inclusion';")
Path(include_b).write_text("b = 'works';")
grammar = grammar.format(include_a=include_a, include_b=include_b)
print(grammar)
model = tatsu.compile(grammar=grammar)
assert model is not None
def test_escape_sequences(self):
self.assertEqual('\n', eval_escapes(r'\n'))
self.assertEqual('this \xeds a test', eval_escapes(r'this \xeds a test'))
self.assertEqual('this ís a test', eval_escapes(r'this \xeds a test'))
self.assertEqual('\nañez', eval_escapes(r'\na\xf1ez'))
self.assertEqual('\nañez', eval_escapes(r'\nañez'))
def test_start(self):
grammar = """
@@grammar :: Test
true = "test" @:`True` $;
false = "test" @:`False` $;
"""
model = tatsu.compile(grammar=grammar)
self.assertEqual('Test', model.directives.get('grammar'))
self.assertEqual('Test', model.name)
# By default, parsing starts from the first rule in the grammar.
ast = model.parse('test')
self.assertEqual(ast, True)
# The start rule can be passed explicitly.
ast = model.parse('test', start='true')
self.assertEqual(ast, True)
# Backward compatibility argument name.
ast = model.parse('test', start='true')
self.assertEqual(ast, True)
# The default rule can be overwritten.
ast = tatsu.parse(grammar, 'test', start='false')
self.assertEqual(ast, False)
# Backward compatibility argument name.
ast = tatsu.parse(grammar, 'test', start='false')
self.assertEqual(ast, False)
def test_rule_capitalization(self):
grammar = """
start = ['test' {rulename}] ;
{rulename} = /[a-zA-Z0-9]+/ ;
"""
test_string = 'test 12'
lowercase_rule_names = ['nocaps', 'camelCase', 'tEST']
uppercase_rule_names = ['Capitalized', 'CamelCase', 'TEST']
ref_lowercase_result = tatsu.parse(
grammar.format(rulename='reflowercase'),
test_string,
)
ref_uppercase_result = tatsu.parse(
grammar.format(rulename='Refuppercase'),
test_string,
)
for rulename in lowercase_rule_names:
result = tatsu.parse(grammar.format(rulename=rulename), test_string)
self.assertEqual(result, ref_lowercase_result)
for rulename in uppercase_rule_names:
result = tatsu.parse(grammar.format(rulename=rulename), test_string)
self.assertEqual(result, ref_uppercase_result)
def test_startrule_issue62(self):
grammar = """
@@grammar::TEST
file_input = expr $ ;
expr = number '+' number ;
number = /[0-9]/ ;
"""
model = tatsu.compile(grammar=grammar)
model.parse('4 + 5')
def test_skip_whitespace(self):
grammar = """
statement = 'FOO' subject $ ;
subject = name:id ;
id = /[a-z]+/ ;
"""
model = tatsu.compile(grammar=grammar)
ast = model.parse('FOO' + ' ' * 3 + 'bar', parseinfo=True)
print(json.dumps(asjson(ast), indent=2))
subject = ast[1]
assert subject['name'] == 'bar'
parseinfo = subject['parseinfo']
assert parseinfo.pos == parseinfo.tokenizer.text.index('bar')
def test_cut_scope(self):
grammar = '''
start =
| one
| two
;
one =
| ~ !() # cut fail
| 'abc';
two = `something` ; # result is the quoted text
'''
ast = tatsu.parse(grammar, 'abc')
assert ast == 'something'
def test_node_parseinfo(self):
grammar = """
@@grammar :: Test
start::Test = true | false ;
true = "test" @:`True` $;
false = "test" @:`False` $;
"""
text = 'test'
node = tatsu.parse(grammar, text, asmodel=True, parseinfo=True)
assert type(node).__name__ == 'Test'
assert node.ast is True
assert node.parseinfo is not None
assert node.parseinfo.pos == 0
assert node.parseinfo.endpos == len(text)
node = tatsu.parse(grammar, text, asmodel=True)
assert type(node).__name__ == 'Test'
assert node.parseinfo is None
|
