test_parse.py 40.5 KB
Newer Older
1
#!/usr/bin/env python3
2

3
"""test_parse.py - tests of the parsers-module of DHParser
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

Author: Eckhart Arnold <arnold@badw.de>

Copyright 2017 Bavarian Academy of Sciences and Humanities

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""

22
import os
23
import sys
24
from functools import partial
25

26
27
scriptpath = os.path.dirname(__file__) or '.'
sys.path.append(os.path.abspath(os.path.join(scriptpath, '..')))
28

eckhart's avatar
eckhart committed
29
from DHParser.configuration import get_config_value, set_config_value
30
from DHParser.toolkit import compile_python_object, re
31
from DHParser.log import is_logging, log_ST, log_parsing_history
32
from DHParser.error import Error, is_error
33
from DHParser.parse import ParserError, Parser, Grammar, Forward, TKN, ZeroOrMore, RE, \
eckhart's avatar
eckhart committed
34
    RegExp, Lookbehind, NegativeLookahead, OneOrMore, Series, Alternative, AllOf, SomeOf, \
35
    Interleave, UnknownParserError, MetaParser, Token, EMPTY_NODE
36
from DHParser import compile_source
37
from DHParser.ebnf import get_ebnf_grammar, get_ebnf_transformer, get_ebnf_compiler, DHPARSER_IMPORTS
38
from DHParser.dsl import grammar_provider
39
from DHParser.syntaxtree import Node, parse_sxpr
40
from DHParser.stringview import StringView
41
from DHParser.trace import set_tracer, trace_history, resume_notices_on
42
43


44
45
46
47
48
49

class TestWhitespace:
    # TODO: add test cases here
    def test_whitespace_comment_mangling(self):
        pass

Eckhart Arnold's avatar
Eckhart Arnold committed
50
    def test_non_empty_derivation(self):
51
52
        pass

53

54
55
class TestParserError:
    def test_parser_error_str(self):
56
        pe = ParserError(Node('TAG', 'test').with_pos(0), StringView('Beispiel'), None, True)
57
58
        assert str(pe).find('Beispiel') >= 0 and str(pe).find('TAG') >= 0

59
60
61
62
63
64
65
66
    def test_false_lookahead_only_message(self):
        """Error.PARSER_LOOKAHEAD_*_ONLY errors must not be reported if there
        no lookahead parser in the history!"""
        lang = """
        word = letters { letters | `-` letters }
        letters = /[A-Za-z]+/
        """
        gr = grammar_provider(lang)()
67
68
        set_tracer(gr, trace_history)
        st = gr('hard-time')
69
        assert not st.errors
70
        st = gr('hard-')
71
72
        assert st.errors and not any(e.code == 1045 for e in st.errors)

eckhart's avatar
eckhart committed
73

eckhart's avatar
eckhart committed
74
75
76
77
78
79
80
81
82
83
class TestParserClass:
    def test_apply(self):
        minilang ="""
            expr = expr ("+"|"-") term | term
            term = term ("*"|"/") factor | factor
            factor = /[0-9]+/~
            """
        gr = grammar_provider(minilang)()
        l = []
        def visitor(p: Parser):
di68kap's avatar
di68kap committed
84
            l.append(p.pname + p.ptype)
eckhart's avatar
eckhart committed
85
86
87
88
89
90
91
92
93
94
95
        gr.root__.apply(visitor)
        s1 = ", ".join(l)
        l = []
        gr.root__.apply(visitor)
        s2 = ", ".join(l)
        l = []
        gr.root__.apply(visitor)
        s3 = ", ".join(l)
        assert s1 == s2 == s3


96
class TestInfiLoopsAndRecursion:
97
    def test_direct_left_recursion1(self):
eckhart's avatar
eckhart committed
98
        minilang = """
99
100
101
102
            expr = expr ("+"|"-") term | term
            term = term ("*"|"/") factor | factor
            factor = /[0-9]+/~
            """
103
        snippet = "9 + 8 + 7 + 6 + 5 + 3 * 4"
104
        parser = grammar_provider(minilang)()
105
        assert parser
Eckhart Arnold's avatar
Eckhart Arnold committed
106
        syntax_tree = parser(snippet)
107
108
        assert not is_error(syntax_tree.error_flag), str(syntax_tree.errors_sorted)
        assert snippet == syntax_tree.content, str(syntax_tree)
Eckhart Arnold's avatar
Eckhart Arnold committed
109
        if is_logging():
110
            log_ST(syntax_tree, "test_LeftRecursion_direct.cst")
111
            log_parsing_history(parser, "test_LeftRecursion_direct")
112

113
    def test_direct_left_recursion2(self):
114
115
116
117
118
119
        minilang = """
            expr = ex
            ex   = expr ("+"|"-") term | term
            term = term ("*"|"/") factor | factor
            factor = /[0-9]+/~
            """
120
        snippet = "9 + 8 + 7 + 6 + 5 + 3 * 4"
121
        parser = grammar_provider(minilang)()
122
        assert parser
123
        syntax_tree = parser(snippet)
124
125
        assert not is_error(syntax_tree.error_flag), syntax_tree.errors_sorted
        assert snippet == syntax_tree.content
126

127
    def test_indirect_left_recursion1(self):
128
129
        minilang = """
            Expr    = //~ (Product | Sum | Value)
130
131
            Product = Expr { ('*' | '/') Expr }+
            Sum     = Expr { ('+' | '-') Expr }+
132
            Value   = /[0-9.]+/~ | '(' §Expr ')'
133
            """
134
        parser = grammar_provider(minilang)()
135
        assert parser
136
        snippet = "8 * 4"
137
        syntax_tree = parser(snippet)
138
        assert not is_error(syntax_tree.error_flag), syntax_tree.errors_sorted
139
140
        snippet = "7 + 8 * 4"
        syntax_tree = parser(snippet)
141
        assert not is_error(syntax_tree.error_flag), syntax_tree.errors_sorted
142
143
        snippet = "9 + 8 * (4 + 3)"
        syntax_tree = parser(snippet)
144
145
        assert not is_error(syntax_tree.error_flag), syntax_tree.errors_sorted
        assert snippet == syntax_tree.content
146
        if is_logging():
147
            log_ST(syntax_tree, "test_LeftRecursion_indirect.cst")
148
            log_parsing_history(parser, "test_LeftRecursion_indirect")
149

150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
    # # BEWARE: EXPERIMENTAL TEST can be long running
    # def test_indirect_left_recursion2(self):
    #     arithmetic_syntax = """
    #         expression     = addition | subtraction
    #         addition       = (expression | term) "+" (expression | term)
    #         subtraction    = (expression | term) "-" (expression | term)
    #         term           = multiplication | division
    #         multiplication = (term | factor) "*" (term | factor)
    #         division       = (term | factor) "/" (term | factor)
    #         factor         = [SIGN] ( NUMBER | VARIABLE | group ) { VARIABLE | group }
    #         group          = "(" expression ")"
    #         SIGN           = /[+-]/
    #         NUMBER         = /(?:0|(?:[1-9]\d*))(?:\.\d+)?/~
    #         VARIABLE       = /[A-Za-z]/~
    #         """
    #     arithmetic = grammar_provider(arithmetic_syntax)()
    #     arithmetic.left_recursion_depth__ = 2
    #     assert arithmetic
    #     syntax_tree = arithmetic("(a + b) * (a - b)")
    #     assert syntax_tree.errors
170

171
172
173
    def test_break_inifnite_loop_ZeroOrMore(self):
        forever = ZeroOrMore(RegExp(''))
        result = Grammar(forever)('')  # infinite loops will automatically be broken
174
        assert repr(result) == "Node(':EMPTY', '')", repr(result)
175
176
177
178

    def test_break_inifnite_loop_OneOrMore(self):
        forever = OneOrMore(RegExp(''))
        result = Grammar(forever)('')  # infinite loops will automatically be broken
179
        assert repr(result) == "Node(':EMPTY', '')", repr(result)
180

181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
    # def test_infinite_loops(self):
    #     minilang = """forever = { // } \n"""
    #     try:
    #         parser_class = grammar_provider(minilang)
    #     except CompilationError as error:
    #         assert all(e.code == Error.INFINITE_LOOP for e in error.errors)
    #     save = get_config_value('static_analysis')
    #     set_config_value('static_analysis', 'late')
    #     provider = grammar_provider(minilang)
    #     try:
    #         parser = provider()
    #     except GrammarError as error:
    #         assert error.errors[0][2].code == Error.INFINITE_LOOP
    #     set_config_value('static_analysis', 'none')
    #     parser = provider()
    #     snippet = " "
    #     syntax_tree = parser(snippet)
    #     assert any(e.code == Error.INFINITE_LOOP for e in syntax_tree.errors)
    #     res = parser.static_analysis()
    #     assert res and res[0][2].code == Error.INFINITE_LOOP
    #     minilang = """not_forever = { / / } \n"""
    #     parser = grammar_provider(minilang)()
    #     res = parser.static_analysis()
    #     assert not res
    #     set_config_value('static_analysis', save)
206

eckhart's avatar
eckhart committed
207

Eckhart Arnold's avatar
Eckhart Arnold committed
208
class TestFlowControl:
209
210
    def setup(self):
        self.t1 = """
eckhart's avatar
eckhart committed
211
        All work and no play
212
213
214
215
216
        makes Jack a dull boy
        END
        """
        self.t2 = "All word and not play makes Jack a dull boy END\n"

Eckhart Arnold's avatar
Eckhart Arnold committed
217
    def test_lookbehind(self):
218
        ws = RegExp(r'\s*')
Eckhart Arnold's avatar
Eckhart Arnold committed
219
        end = RegExp("END")
220
        doc_end = Lookbehind(RegExp('\\s*?\\n')) + end
221
        word = RegExp(r'\w+')
Eckhart Arnold's avatar
Eckhart Arnold committed
222
223
224
225
        sequence = OneOrMore(NegativeLookahead(end) + word + ws)
        document = ws + sequence + doc_end + ws

        parser = Grammar(document)
226
227
228
229
230
231
232
        cst = parser(self.t1)
        assert not cst.error_flag, cst.as_sxpr()
        cst = parser(self.t2)
        assert cst.error_flag, cst.as_sxpr()

    def test_lookbehind_indirect(self):
        class LookbehindTestGrammar(Grammar):
eckhart's avatar
eckhart committed
233
            parser_initialization__ = ["upon instantiation"]
234
            ws = RegExp(r'\s*')
235
            end = RegExp('END')
236
            SUCC_LB = RegExp('\\s*?\\n')
237
            doc_end = Series(Lookbehind(SUCC_LB), end)
238
            word = RegExp(r'\w+')
239
240
241
242
243
244
            sequence = OneOrMore(Series(NegativeLookahead(end), word, ws))
            document = Series(ws, sequence, doc_end, ws)
            root__ = document

        parser = LookbehindTestGrammar()
        cst = parser(self.t1)
Eckhart Arnold's avatar
Eckhart Arnold committed
245
        assert not cst.error_flag, cst.as_sxpr()
246
        cst = parser(self.t2)
Eckhart Arnold's avatar
Eckhart Arnold committed
247
248
249
        assert cst.error_flag, cst.as_sxpr()


250
251
252
253
254
255
256
class TestRegex:
    def test_multilineRegex(self):
        mlregex = r"""
        regex =  /\w+    # one or more alphabetical characters including the underscore
                  [+]    # followed by a plus sign
                  \w*    # possibly followed by more alpha chracters/
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
257
        result, messages, _ = compile_source(mlregex, None, get_ebnf_grammar(),
Eckhart Arnold's avatar
Eckhart Arnold committed
258
                        get_ebnf_transformer(), get_ebnf_compiler('MultilineRegexTest'))
259
        assert result
260
        assert not messages, str(messages)
261
        parser = compile_python_object(DHPARSER_IMPORTS + result, r'\w+Grammar$')()
eckhart's avatar
eckhart committed
262
263
        node = parser('abc+def', parser.regex)
        assert not node.error_flag
264
        assert node.tag_name == "regex"
265
266
        assert str(node) == 'abc+def'

267
268
    def test_multilineRegex_wo_Comments(self):
        mlregex = r"""
eckhart's avatar
eckhart committed
269
270
        regex =  /\w+
                  [+]
271
272
                  \w* /
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
273
        result, messages, _ = compile_source(mlregex, None, get_ebnf_grammar(),
274
275
276
                        get_ebnf_transformer(), get_ebnf_compiler('MultilineRegexTest'))
        assert result
        assert not messages, str(messages)
277
        parser = compile_python_object(DHPARSER_IMPORTS + result, r'\w+Grammar$')()
278
279
        node = parser('abc+def', parser.regex)
        assert not node.error_flag
280
        assert node.tag_name == "regex"
281
282
        assert str(node) == 'abc+def'

283
284
285
286
287
    def text_ignore_case(self):
        mlregex = r"""
        @ ignorecase = True
        regex = /alpha/
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
288
        result, messages, _ = compile_source(mlregex, None, get_ebnf_grammar(),
289
290
291
                        get_ebnf_transformer(), get_ebnf_compiler('MultilineRegexTest'))
        assert result
        assert not messages
292
        parser = compile_python_object(DHPARSER_IMPORTS + result, r'\w+Grammar$')()
293
294
295
296
        node, rest = parser.regex('Alpha')
        assert node
        assert not node.error_flag
        assert rest == ''
297
        assert node.tag_name == "regex"
298
299
300
301
302
303
        assert str(node) == 'Alpha'

        mlregex = r"""
        @ ignorecase = False
        regex = /alpha/
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
304
        result, messages, _ = compile_source(mlregex, None, get_ebnf_grammar(),
305
306
307
                        get_ebnf_transformer(), get_ebnf_compiler('MultilineRegexTest'))
        assert result
        assert not messages
308
        parser = compile_python_object(DHPARSER_IMPORTS + result, r'\w+Grammar$')()
309
310
311
312
        node, rest = parser.regex('Alpha')
        assert node.error_flag


313
314
315
316
317
318
319
320
321
322
323
324
    def test_token(self):
        tokenlang = r"""
            @whitespace = linefeed
            lang        = "" begin_token {/\w+/ ""} end_token
            begin_token = "\begin{document}"
            end_token   = "\end{document}"
            """
        testdoc = r"""
            \begin{document}
            test
            \end{document}
            """
Eckhart Arnold's avatar
Eckhart Arnold committed
325
        result, messages, _ = compile_source(
eckhart's avatar
eckhart committed
326
327
            tokenlang, None, get_ebnf_grammar(), get_ebnf_transformer(),
            get_ebnf_compiler("TokenTest"))
328
        assert result
eckhart's avatar
eckhart committed
329
        assert not messages, str(messages)
330
        parser = compile_python_object(DHPARSER_IMPORTS + result, r'\w+Grammar$')()
Eckhart Arnold's avatar
Eckhart Arnold committed
331
        result = parser(testdoc)
332
        # log_parsing_history(parser, "test.log")
333
334
        assert not result.error_flag

335

336
class TestGrammar:
337
    def setup(self):
338
339
340
341
342
343
        grammar = r"""@whitespace = horizontal
        haupt        = textzeile LEERZEILE
        textzeile    = { WORT }+
        WORT         = /[^ \t]+/~
        LEERZEILE    = /\n[ \t]*(?=\n)/~
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
344
345
        self.pyparser, messages, _ = compile_source(grammar, None, get_ebnf_grammar(),
                                    get_ebnf_transformer(), get_ebnf_compiler("PosTest"))
346
        assert self.pyparser
347
        assert not messages
348
349
350
351

    def test_pos_values_initialized(self):
        # checks whether pos values in the parsing result and in the
        # history record have been initialized
352
353
        grammar = compile_python_object(DHPARSER_IMPORTS + self.pyparser, r'\w+Grammar$')()
        grammar("no_file_name*")
354
        for record in grammar.history__:
355
356
            assert not record.node or record.node.pos >= 0

357
    def test_select_parsing(self):
358
        grammar = compile_python_object(DHPARSER_IMPORTS + self.pyparser, r'\w+Grammar$')()
359
360
361
362
        grammar("wort", "WORT")
        grammar("eine Zeile", "textzeile")
        grammar("kein Haupt", "haupt")
        grammar("so ist es richtig", "haupt")
363

di68kap's avatar
di68kap committed
364
365
    def test_grammar_subclassing(self):
        class Arithmetic(Grammar):
366
            r'''
di68kap's avatar
di68kap committed
367
368
369
370
371
372
            expression =  term  { ("+" | "-") term }
            term       =  factor  { ("*" | "/") factor }
            factor     =  INTEGER | "("  expression  ")"
            INTEGER    =  /\d+/~
            '''
            expression = Forward()
373
374
375
376
            INTEGER = RE('\\d+')
            factor = INTEGER | TKN("(") + expression + TKN(")")
            term = factor + ZeroOrMore((TKN("*") | TKN("/")) + factor)
            expression.set(term + ZeroOrMore((TKN("+") | TKN("-")) + term))
di68kap's avatar
di68kap committed
377
378
379
380
381
382
            root__ = expression

        grammar = Arithmetic()
        CST = grammar('3+4')
        assert not CST.error_flag, CST.as_sxpr()

383
384
385
386
387
388
389
390
391
392
393
    def test_incomplete_matching(self):
        """Tests whether the flag `complete_match` works as expected when
        calling a grammar object in order to parse a document."""
        gr = grammar_provider('word = ~/\\w+/\n')()
        st = gr('eins')
        assert not st.errors
        st = gr('eins zwei')
        assert st.errors[0].code == Error.PARSER_STOPPED_BEFORE_END
        st = gr('eins zwei', complete_match=False)
        assert not st.errors

394
    def test_synonym(self):
di68kap's avatar
di68kap committed
395
        lang = r"""
396
397
398
399
400
401
402
403
404
405
406
407
408
            doc  = { word | number }
            word = /\w+/ S
            number = [VZ] /\d+/ S 
            S    = ~        # let S by a synonym for anonymous whitespace
            VZ   = "-"
        """
        gr = grammar_provider(lang)()
        st = gr('eins 1 zwei2drei 3')
        # set_config_value('compiled_EBNF_log', 'grammar.log')
        gr = grammar_provider("@drop = whitespace, token" + lang)()
        st = gr('eins 1 zwei2drei 3')
        st = gr('-3')

409

410
411
412
413
414
415
416
class TestSeries:
    def test_non_mandatory(self):
        lang = """
        document = series | /.*/
        series = "A" "B" "C" "D"
        """
        parser = grammar_provider(lang)()
Eckhart Arnold's avatar
Eckhart Arnold committed
417
        st = parser("ABCD")
418
        assert not st.error_flag
Eckhart Arnold's avatar
Eckhart Arnold committed
419
        st = parser("A_CD")
420
        assert not st.error_flag
Eckhart Arnold's avatar
Eckhart Arnold committed
421
        st = parser("AB_D")
422
423
424
425
426
427
428
429
430
431
432
        assert not st.error_flag

    def test_mandatory(self):
        """Test for the §-operator. The Series-parser should raise an
        error for any non-match that occurs after the mandatory-operator.
        """
        lang = """
        document = series | /.*/
        series = "A" "B" §"C" "D"
        """
        parser = grammar_provider(lang)()
433
434
435
        st = parser("ABCD");  assert not st.error_flag
        st = parser("A_CD");  assert not st.error_flag
        st = parser("AB_D");  assert st.error_flag
436
        assert st.errors_sorted[0].code == Error.MANDATORY_CONTINUATION
437
        # transitivity of mandatory-operator
438
        st = parser("ABC_");  assert st.error_flag
439
        assert st.errors_sorted[0].code == Error.MANDATORY_CONTINUATION
440
441

    def test_series_composition(self):
442
        TA, TB, TC, TD, TE = (TKN(b) for b in "ABCDE")
443
444
445
446
447
        s1 = Series(TA, TB, TC, mandatory=2)
        s2 = Series(TD, TE)

        combined = Alternative(s1 + s2, RegExp('.*'))
        parser = Grammar(combined)
448
449
450
        st = parser("ABCDE");  assert not st.error_flag
        st = parser("A_CDE");  assert not st.error_flag
        st = parser("AB_DE");  assert st.error_flag
451
        assert st.errors_sorted[0].code == Error.MANDATORY_CONTINUATION
452
        st = parser("ABC_E");  assert st.error_flag
453
        assert st.errors_sorted[0].code == Error.MANDATORY_CONTINUATION
454
455
456

        combined = Alternative(s2 + s1, RegExp('.*'))
        parser = Grammar(combined)
457
458
459
460
461
462
        st = parser("DEABC");  assert not st.error_flag
        st = parser("_EABC");  assert not st.error_flag
        st = parser("D_ABC");  assert not st.error_flag
        st = parser("DE_BC");  assert not st.error_flag
        st = parser("DEA_C");  assert not st.error_flag
        st = parser("DEAB_");  assert st.error_flag
463
        assert st.errors_sorted[0].code == Error.MANDATORY_CONTINUATION
464

eckhart's avatar
eckhart committed
465
466
467
468
469
470
471
472
473
474
    # def test_boundary_cases(self):
    #     lang = """
    #     document = series | §!single | /.*/
    #     series = "A" "B" §"C" "D"
    #     single = "E"
    #     """
    #     parser_class = grammar_provider(lang)
    #     parser = parser_class()
    #     print(parser.python_src__)
    #     print(parser_class.python_src__)
eckhart's avatar
eckhart committed
475

476
477
    def test_ebnf_serialization(self):
        ebnf_grammar = get_ebnf_grammar()
eckhart's avatar
eckhart committed
478
        # TODO: Add test here
479
        ebnf = ebnf_grammar.as_ebnf()
480
        # print(ebnf)
481
482


483
484
485
class TestAllOfSomeOf:
    def test_allOf_order(self):
        """Test that parsers of an AllOf-List can match in arbitrary order."""
486
        prefixes = AllOf(TKN("A"), TKN("B"))
487
488
        assert Grammar(prefixes)('A B').content == 'A B'
        assert Grammar(prefixes)('B A').content == 'B A'
489
490
491
492

    def test_allOf_completeness(self):
        """Test that an error is raised if not  all parsers of an AllOf-List
        match."""
493
        prefixes = AllOf(TKN("A"), TKN("B"))
494
495
496
497
498
        assert Grammar(prefixes)('B').error_flag

    def test_allOf_redundance(self):
        """Test that one and the same parser may be listed several times
        and must be matched several times accordingly."""
499
        prefixes = AllOf(TKN("A"), TKN("B"), TKN("A"))
500
501
502
        assert Grammar(prefixes)('A A B').content == 'A A B'
        assert Grammar(prefixes)('A B A').content == 'A B A'
        assert Grammar(prefixes)('B A A').content == 'B A A'
503
504
505
506
        assert Grammar(prefixes)('A B B').error_flag

    def test_someOf_order(self):
        """Test that parsers of an AllOf-List can match in arbitrary order."""
507
        prefixes = SomeOf(TKN("A"), TKN("B"))
508
509
        assert Grammar(prefixes)('A B').content == 'A B'
        assert Grammar(prefixes)('B A').content == 'B A'
510
        prefixes = SomeOf(TKN("B"), TKN("A"))
511
512
        assert Grammar(prefixes)('A B').content == 'A B'
        assert Grammar(prefixes)('B').content == 'B'
513
514
515
516

    def test_someOf_redundance(self):
        """Test that one and the same parser may be listed several times
        and must be matched several times accordingly."""
517
        prefixes = SomeOf(TKN("A"), TKN("B"), TKN("A"))
518
519
520
        assert Grammar(prefixes)('A A B').content == 'A A B'
        assert Grammar(prefixes)('A B A').content == 'A B A'
        assert Grammar(prefixes)('B A A').content == 'B A A'
521
522
523
        assert Grammar(prefixes)('A B B').error_flag


524
525
526
527
528
class TestInterleave:
    def test_interleave_most_simple(self):
        letterset = Interleave(Token("A"), Token("B"), Token("C"))
        gr = Grammar(letterset)
        st = gr('ABC')
529
        assert not st.errors, str(st.errors)
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
        assert st.content == "ABC"
        st = gr('BCA')
        assert not st.errors
        assert st.content == "BCA"
        st = gr('BCBA')
        assert st.errors
        st = gr('AB')
        assert st.errors

    def test_interleave(self):
        letterset = Interleave(Token("A"), Token("B"), Token("C"),
                               repetitions=[(1, 1000), (0, 1), (1, 1)])
        gr = Grammar(letterset)
        st = gr('AABC')
        assert not st.errors
545
546
547
548
549
550
551
552
553
554
555
556
        st = gr('BACAAA')
        assert not st.errors
        st = gr('ABCC')
        assert st.errors
        st = gr('AAACAAA')
        assert not st.errors
        st = gr('AAABAAA')
        assert st.errors




557
558


559
560
561
562
class TestErrorRecovery:
    def test_series_skip(self):
        lang = """
        document = series | /.*/
563
        @series_skip = /(?=[A-Z])/
564
565
566
567
568
        series = "A" "B" §"C" "D"
        """
        parser = grammar_provider(lang)()
        st = parser('AB_D')
        assert len(st.errors) == 1  # no additional "stopped before end"-error!
569
        resume_notices_on(parser)
570
571
        st = parser('AB_D')
        assert len(st.errors) == 2 and any(err.code == Error.RESUME_NOTICE for err in st.errors)
eckhart's avatar
eckhart committed
572
        assert 'Skipping' in str(st.errors_sorted[1])
573

574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599

    def test_AllOf_skip(self):
        lang = """
        document = allof | /.*/
        @allof_skip = /[A-Z]/
        allof = < "A" §"B" "C" "D" >
        """
        parser = grammar_provider(lang)()
        st = parser('CADB')
        assert 'allof' in st and st['allof'].content == "CADB"
        st = parser('_BCD')
        assert st.equals(parse_sxpr('(document "_BCD")'))
        st = parser('_ABC')
        assert st.equals(parse_sxpr('(document "_ABC")'))
        st = parser('A_CD')
        assert st['allof'].content == "A_CD"
        st = parser('AB_D')
        assert st['allof'].content == "AB_D"
        st = parser('A__D')
        assert st['allof'].content == "A__D"
        st = parser('CA_D')
        assert st['allof'].content == "CA_D"
        st = parser('BC_A')
        assert st['allof'].content == "BC_A"


600
class TestPopRetrieve:
601
    mini_language = r"""
602
603
        document       = { text | codeblock }
        codeblock      = delimiter { text | (!:delimiter delimiter_sign) } ::delimiter
604
        delimiter      = delimiter_sign  # never use delimiter between capture and pop except for retrival!
605
        delimiter_sign = /`+/
eckhart's avatar
eckhart committed
606
        text           = /[^`]+/
607
        """
608
    mini_lang2 = r"""
609
610
611
612
613
614
615
616
        @braces_filter=counterpart
        document       = { text | codeblock }
        codeblock      = braces { text | opening_braces | (!:braces closing_braces) } ::braces
        braces         = opening_braces
        opening_braces = /\{+/
        closing_braces = /\}+/
        text           = /[^{}]+/
        """
617
    mini_lang3 = r"""
618
619
620
621
        document       = { text | env }
        env            = (specialtag | opentag) text [closespecial | closetag]
        opentag        = "<" name ">"
        specialtag     = "<" /ABC/ !name ">"
eckhart's avatar
eckhart committed
622
        closetag       = close_slash | close_star
623
624
625
626
627
628
629
630
        close_slash    = "<" ::name "/>"
        close_star     = "<" ::name "*>"
        closespecial   = "<" /ABC/~ ">"
        name           = /\w+/~
        text           = /[^<>]+/
        """

    def setup(self):
631
632
633
        self.minilang_parser = grammar_provider(self.mini_language)()
        self.minilang_parser2 = grammar_provider(self.mini_lang2)()
        self.minilang_parser3 = grammar_provider(self.mini_lang3)()
634
635
636

    @staticmethod
    def opening_delimiter(node, name):
637
        return node.tag_name == name # and not isinstance(node.parser, Retrieve)
638
639
640

    @staticmethod
    def closing_delimiter(node):
641
642
        return node.tag_name in {':Pop', ':Retrieve'}
        # return isinstance(node.parser, Retrieve)
643
644
645
646
647
648
649
650
651

    def test_compile_mini_language(self):
        assert self.minilang_parser
        assert self.minilang_parser2
        assert self.minilang_parser3

    def test_stackhandling(self):
        ambigous_opening = "<ABCnormal> normal tag <ABCnormal*>"
        syntax_tree = self.minilang_parser3(ambigous_opening)
652
        assert not syntax_tree.error_flag, str(syntax_tree.errors_sorted)
653
654
655

        ambigous_opening = "<ABCnormal> normal tag <ABCnormal/>"
        syntax_tree = self.minilang_parser3(ambigous_opening)
656
        assert not syntax_tree.error_flag, str(syntax_tree.errors_sorted)
657
658
659

        forgot_closing_tag = "<em> where is the closing tag?"
        syntax_tree = self.minilang_parser3(forgot_closing_tag)
660
        assert syntax_tree.error_flag, str(syntax_tree.errors_sorted)
661
662
663

        proper = "<em> has closing tag <em/>"
        syntax_tree = self.minilang_parser3(proper)
664
        assert not syntax_tree.error_flag, str(syntax_tree.errors_sorted)
665
666
667

        proper = "<em> has closing tag <em*>"
        syntax_tree = self.minilang_parser3(proper)
668
        assert not syntax_tree.error_flag, str(syntax_tree.errors_sorted)
669

670
    def test_cache_neutrality(self):
671
672
        """Test that packrat-caching does not interfere with the variable-
        changing parsers: Capture and Retrieve."""
673
        lang = r"""
674
675
676
677
678
679
680
681
682
            text = opening closing
            opening = (unmarked_package | marked_package)
            closing = ::variable
            unmarked_package = package "."
            marked_package = package "*" "."
            package = "(" variable ")"
            variable = /\w+/~
            """
        case = "(secret)*. secret"
683
        gr = grammar_provider(lang)()
684
        st = gr(case)
685
        assert not st.error_flag, str(st.errors_sorted)
686
687
688
689

    def test_single_line(self):
        teststr = "Anfang ```code block `` <- keine Ende-Zeichen ! ``` Ende"
        syntax_tree = self.minilang_parser(teststr)
690
        assert not syntax_tree.errors_sorted
691
692
        delim = str(next(syntax_tree.select_if(partial(self.opening_delimiter, name="delimiter"))))
        pop = str(next(syntax_tree.select_if(self.closing_delimiter)))
693
694
        assert delim == pop
        if is_logging():
695
            log_ST(syntax_tree, "test_PopRetrieve_single_line.cst")
696
697
698
699
700
701
702
703
704
705
706

    def test_multi_line(self):
        teststr = """
            Anfang ```code block `` <- keine Ende-Zeichen ! ``` Ebde

            Absatz ohne ``` codeblock, aber
            das stellt sich erst am Ende herause...

            Mehrzeliger ```code block
            """
        syntax_tree = self.minilang_parser(teststr)
707
        assert not syntax_tree.errors_sorted
708
709
        delim = str(next(syntax_tree.select_if(partial(self.opening_delimiter, name="delimiter"))))
        pop = str(next(syntax_tree.select_if(self.closing_delimiter)))
710
711
        assert delim == pop
        if is_logging():
712
            log_ST(syntax_tree, "test_PopRetrieve_multi_line.cst")
713
714
715
716

    def test_single_line_complement(self):
        teststr = "Anfang {{{code block }} <- keine Ende-Zeichen ! }}} Ende"
        syntax_tree = self.minilang_parser2(teststr)
717
        assert not syntax_tree.errors_sorted
718
719
        delim = str(next(syntax_tree.select_if(partial(self.opening_delimiter, name="braces"))))
        pop = str(next(syntax_tree.select_if(self.closing_delimiter)))
720
721
        assert len(delim) == len(pop) and delim != pop
        if is_logging():
722
            log_ST(syntax_tree, "test_PopRetrieve_single_line.cst")
723
724
725
726
727
728
729
730
731
732
733

    def test_multi_line_complement(self):
        teststr = """
            Anfang {{{code block {{ <- keine Ende-Zeichen ! }}} Ende

            Absatz ohne {{{ codeblock, aber
            das stellt sich erst am Ende heraus...

            Mehrzeliger }}}code block
            """
        syntax_tree = self.minilang_parser2(teststr)
734
        assert not syntax_tree.errors_sorted
735
736
        delim = str(next(syntax_tree.select_if(partial(self.opening_delimiter, name="braces"))))
        pop = str(next(syntax_tree.select_if(self.closing_delimiter)))
737
738
        assert len(delim) == len(pop) and delim != pop
        if is_logging():
739
            log_ST(syntax_tree, "test_PopRetrieve_multi_line.cst")
740
741


742
class TestWhitespaceHandling:
Eckhart Arnold's avatar
Eckhart Arnold committed
743
    minilang = """
744
745
746
747
748
749
750
751
752
        doc = A B
        A = "A"
        B = "B"
        Rdoc = ar br
        ar = /A/
        br = /B/
        """

    def setup(self):
753
        self.gr = grammar_provider(self.minilang)()
754
755
756
757
758
759
760
761
762
763
764
765

    def test_token_whitespace(self):
        st = self.gr("AB", 'doc')
        assert not st.error_flag
        st = self.gr("A B", 'doc')
        assert not st.error_flag

    def test_regexp_whitespace(self):
        st = self.gr("AB", 'Rdoc')
        assert not st.error_flag
        st = self.gr("A B", 'Rdoc')
        assert st.error_flag
di68kap's avatar
di68kap committed
766
767
768
769
770


class TestErrorReporting:
    grammar = """
        root      = series alpha | anything
eckhart's avatar
eckhart committed
771
        series    = subseries &alpha
di68kap's avatar
di68kap committed
772
773
774
775
776
777
778
779
780
781
782
783
784
785
        subseries = alpha §beta
        alpha     = /[a-z]+/
        beta      = /[A-Z]+/
        anything  = /.*/
        """

    def setup(self):
        self.parser = grammar_provider(self.grammar)()

    def test_error_propagation(self):
        testcode1 = "halloB"
        testcode2 = "XYZ"
        testcode3 = "hallo "
        cst = self.parser(testcode1)
786
        assert not cst.error_flag, str(cst.errors_sorted)
di68kap's avatar
di68kap committed
787
788
789
790
        cst = self.parser(testcode2)
        assert not cst.error_flag
        cst = self.parser(testcode3)
        assert cst.error_flag
791
792


di68kap's avatar
di68kap committed
793
794
class TestBorderlineCases:
    def test_not_matching(self):
795
        minilang = """parser = /X/\n"""
di68kap's avatar
di68kap committed
796
797
798
799
        gr = grammar_provider(minilang)()
        cst = gr('X', 'parser')
        assert not cst.error_flag
        cst = gr(' ', 'parser')
800
        assert cst.error_flag and cst.errors_sorted[0].code == Error.PARSER_DID_NOT_MATCH
di68kap's avatar
di68kap committed
801
        cst = gr('', 'parser')
802
        assert cst.error_flag and cst.errors_sorted[0].code == Error.PARSER_DID_NOT_MATCH
di68kap's avatar
di68kap committed
803
804
805
806
807
808
809

    def test_matching(self):
        minilang = """parser = /.?/"""
        gr = grammar_provider(minilang)()
        cst = gr(' ', 'parser')
        assert not cst.error_flag
        cst = gr('  ', 'parser')
810
        assert cst.error_flag and cst.errors_sorted[0].code == Error.PARSER_STOPPED_BEFORE_END
di68kap's avatar
di68kap committed
811
812
813
814
        cst = gr('', 'parser')
        assert not cst.error_flag


Eckhart Arnold's avatar
Eckhart Arnold committed
815
class TestReentryAfterError:
816
    def setup(self):
Eckhart Arnold's avatar
Eckhart Arnold committed
817
818
819
820
821
        lang = """
        document = alpha [beta] gamma "."
          alpha = "ALPHA" abc
            abc = §"a" "b" "c"
          beta = "BETA" (bac | bca)
822
823
            bac = "b" "a" §"c"
            bca = "b" "c" §"a"
Eckhart Arnold's avatar
Eckhart Arnold committed
824
825
826
827
          gamma = "GAMMA" §(cab | cba)
            cab = "c" "a" §"b"
            cba = "c" "b" §"a"
        """
828
        self.gr = grammar_provider(lang)()
829

830
831
    def test_no_resume_rules(self):
        gr = self.gr;  gr.resume_rules = dict()
832
833
        content = 'ALPHA acb BETA bac GAMMA cab .'
        cst = gr(content)
834
835
836
837
        assert cst.error_flag
        assert cst.content == content
        assert cst.pick('alpha').content.startswith('ALPHA')

eckhart's avatar
eckhart committed
838
839
840
841
842
843
844
845
    def test_no_resume_rules_partial_parsing(self):
        gr = self.gr;  gr.resume_rules = dict()
        content = 'ALPHA acb'
        cst = gr(content, 'alpha')
        assert cst.error_flag
        assert cst.content == content
        assert cst.pick('alpha').content.startswith('ALPHA')

846
847
    def test_simple_resume_rule(self):
        gr = self.gr;  gr.resume_rules = dict()
848
        gr.resume_rules__['alpha'] = [re.compile(r'(?=BETA)')]
849
        content = 'ALPHA acb BETA bac GAMMA cab .'
850
851
852
853
        cst = gr(content)
        assert cst.error_flag
        assert cst.content == content
        assert cst.pick('alpha').content.startswith('ALPHA')
854
        # because of resuming, there should be only one error message
Eckhart Arnold's avatar
Eckhart Arnold committed
855
        assert len([err for err in cst.errors_sorted if err.code >= 1000]) == 1
856

857
858
    def test_failing_resume_rule(self):
        gr = self.gr;  gr.resume_rules = dict()
859
        gr.resume_rules__['alpha'] = [re.compile(r'(?=XXX)')]
860
        content = 'ALPHA acb BETA bac GAMMA cab .'
861
862
863
864
865
        cst = gr(content)
        assert cst.error_flag
        assert cst.content == content
        # assert cst.pick('alpha').content.startswith('ALPHA')

eckhart's avatar
eckhart committed
866
    def test_several_reentry_points(self):
867
        gr = self.gr;  gr.resume_rules = dict()
868
        gr.resume_rules__['alpha'] = [re.compile(r'(?=BETA)'), re.compile(r'(?=GAMMA)')]
869
        content = 'ALPHA acb BETA bac GAMMA cab .'
870
871
872
873
        cst = gr(content)
        assert cst.error_flag
        assert cst.content == content
        assert cst.pick('alpha').content.startswith('ALPHA')
874
        # because of resuming, there should be only one error message
Eckhart Arnold's avatar
Eckhart Arnold committed
875
        assert len([err for err in cst.errors_sorted if err.code >= 1000]) == 1
876

877
878
    def test_several_reentry_points_second_point_matching(self):
        gr = self.gr;  gr.resume_rules = dict()
879
        gr.resume_rules__['alpha'] = [re.compile(r'(?=BETA)'), re.compile(r'(?=GAMMA)')]
880
881
        content = 'ALPHA acb GAMMA cab .'
        cst = gr(content)
Eckhart Arnold's avatar
Eckhart Arnold committed
882
        assert cst.error_flag
883
        assert cst.content == content
884
        assert cst.pick('alpha').content.startswith('ALPHA')
885
        # because of resuming, there should be only one error message
886
        assert len(cst.errors_sorted) == 1
887
888
        resume_notices_on(gr)
        cst = gr(content)
889
        assert len(cst.errors) == 2 and any(err.code == Error.RESUME_NOTICE for err in cst.errors)
890

891
892
    def test_several_resume_rules_innermost_rule_matching(self):
        gr = self.gr;  gr.resume_rules = dict()
893
894
895
        gr.resume_rules__['alpha'] = [re.compile(r'(?=BETA)'), re.compile(r'(?=GAMMA)')]
        gr.resume_rules__['beta'] = [re.compile(r'(?=GAMMA)')]
        gr.resume_rules__['bac'] = [re.compile(r'(?=GAMMA)')]
896
897
898
899
900
        content = 'ALPHA abc BETA bad GAMMA cab .'
        cst = gr(content)
        assert cst.error_flag
        assert cst.content == content
        assert cst.pick('alpha').content.startswith('ALPHA')
901
        # because of resuming, there should be only one error message
Eckhart Arnold's avatar
Eckhart Arnold committed
902
        assert len([err for err in cst.errors_sorted if err.code >= 1000]) == 1
903
904
905
906
907
908
        # multiple failures
        content = 'ALPHA acb BETA bad GAMMA cab .'
        cst = gr(content)
        assert cst.error_flag
        assert cst.content == content
        assert cst.pick('alpha').content.startswith('ALPHA')
909
        # there should be only two error messages
Eckhart Arnold's avatar
Eckhart Arnold committed
910
        assert len([err for err in cst.errors_sorted if err.code >= 1000]) == 2
911

912
    def test_skip_comment_on_resume(self):
913
914
        lang = r"""
            @ comment =  /(?:\/\/.*)|(?:\/\*(?:.|\n)*?\*\/)/  # Kommentare im C++-Stil
915
            document = block_A block_B
916
            @ block_A_resume = /(?=x)/
917
918
            block_A = "a" §"b" "c"
            block_B = "x" "y" "z"
919
        """
920
921
922
923
924
925
926
927
928
929
930
931
        def mini_suite(grammar):
            tree = grammar('abc/*x*/xyz')
            assert not tree.errors
            tree = grammar('abDxyz')
            mandatory_cont = (Error.MANDATORY_CONTINUATION, Error.MANDATORY_CONTINUATION_AT_EOF)
            assert len(tree.errors) == 1 and tree.errors[0].code in mandatory_cont
            tree = grammar('abD/*x*/xyz')
            assert len(tree.errors) == 1 and tree.errors[0].code in mandatory_cont
            tree = grammar('aD /*x*/ c /* a */ /*x*/xyz')
            assert len(tree.errors) == 1 and tree.errors[0].code in mandatory_cont

        # test regex-defined resume rule
932
        grammar = grammar_provider(lang)()
933
        mini_suite(grammar)
934

935

936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
    def test_unambiguous_error_location(self):
        lang = r"""
            @ drop        = whitespace, token  # drop tokens and whitespace early
           
            @object_resume = /(?<=\})/
           
            json       = ~ value EOF
            value      = object | string 
            object     = "{" [member { "," §member }] "}"
            member     = string §":" value
            string     = `"` CHARACTERS `"` ~

            CHARACTERS = { /[^"\\]+/ }                  
            EOF      =  !/./        # no more characters ahead, end of file reached
            """
        test_case = """{
                "missing member": "abcdef",
            }"""
        gr = grammar_provider(lang)()
        cst = gr(test_case)
        assert any(err.code == Error.MANDATORY_CONTINUATION for err in cst.errors)


959
class TestConfiguredErrorMessages:
960
    def test_configured_error_message(self):
961
962
963
        lang = """
            document = series | /.*/
            @series_error = "a badly configured error message {5}"
964
            series = /X/ | head §"C" "D"
965
966
967
968
            head = "A" "B"
            """
        parser = grammar_provider(lang)()
        st = parser("AB_D");  assert st.error_flag
969
970
        assert st.errors_sorted[0].code == Error.MALFORMED_ERROR_STRING
        assert st.errors_sorted[1].code == Error.MANDATORY_CONTINUATION
971
972


973
974
975
976
977
978
979
980
981
982
class TestUnknownParserError:
    def test_unknown_parser_error(self):
        gr = Grammar()
        try:
            gr("", "NonExistantParser")
            assert False, "UnknownParserError expected!"
        except UnknownParserError:
            pass


983
984
class TestEarlyTokenWhitespaceDrop:
    def setup(self):
985
        self.lang = r"""
986
987
988
            @ drop = token, whitespace
            expression = term  { ("+" | "-") term}
            term       = factor  { ("*"|"/") factor}
eckhart's avatar
eckhart committed
989
            factor     = number | variable | "("  expression  ")"
990
                       | constant | fixed
991
            variable   = /[a-z]/~
992
993
            number     = /\d+/~
            constant   = "A" | "B"
eckhart's avatar
eckhart committed
994
            fixed      = "X"
995
996
997
            """
        self.gr = grammar_provider(self.lang)()

998
    def test_drop(self):
999
1000
        cst = self.gr('4 + 3 * 5')
        assert not cst.pick(':Token')