test_ebnf.py 11.4 KB
Newer Older
1
2
#!/usr/bin/python3

3
"""test_ebnf.py - tests of the ebnf module of DHParser 
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
                             

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.
"""

23
from functools import partial
24
25
26
import os
import sys
sys.path.append(os.path.abspath('../../'))
27
from DHParser.parsers import full_compilation, Retrieve, WHITESPACE_KEYWORD, nil_scanner
28
from DHParser.ebnf import EBNFGrammar, EBNFTransform, EBNFCompiler
29
from DHParser.dsl import compileEBNF, compileDSL
30
31
32
33
34


WRITE_LOGS = True


35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
class TestDirectives:
    mini_language = """
        expression =  term  { ("+" | "-") term }
        term       =  factor  { ("*" | "/") factor }
        factor     =  constant | "("  expression  ")"
        constant   =  digit { digit } [ //~ ]
        digit      = /0/ | /1/ | /2/ | /3/ | /4/ | /5/ | /6/ | /7/ | /8/ | /9/ 
        """

    def test_whitespace_linefeed(self):
        lang = "@ whitespace = linefeed\n" + self.mini_language
        MinilangParser = compileEBNF(lang)
        parser = MinilangParser()
        assert parser
        syntax_tree = parser.parse("3 + 4 * 12")
50
        # parser.log_parsing_history("WSP")
51
52
        assert not syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n * 12")
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
        # parser.log_parsing_history("WSPLF")
        assert not syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n \n * 12")
        assert syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n\n * 12")
        assert syntax_tree.collect_errors()

    def test_whitespace_vertical(self):
        lang = "@ whitespace = vertical\n" + self.mini_language
        parser = compileEBNF(lang)()
        assert parser
        syntax_tree = parser.parse("3 + 4 * 12")
        assert not syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n * 12")
        assert not syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n \n * 12")
        assert not syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n\n * 12")
71
72
        assert not syntax_tree.collect_errors()

73
74
    def test_whitespace_horizontal(self):
        lang = "@ whitespace = horizontal\n" + self.mini_language
75
76
77
78
79
80
81
        parser = compileEBNF(lang)()
        assert parser
        syntax_tree = parser.parse("3 + 4 * 12")
        assert not syntax_tree.collect_errors()
        syntax_tree = parser.parse("3 + 4 \n * 12")
        assert syntax_tree.collect_errors()

82

83
class TestEBNFParser:
di68kap's avatar
di68kap committed
84
85
86
87
    test_json = [
""
]

88
89
90
91
92
93
94
95
96
97
98
99
100
101
    def setup(self):
        self.EBNF = EBNFGrammar()

    def test_literal(self):
        snippet = '"literal" '
        result = self.EBNF.parse(snippet, 'literal')
        assert not result.error_flag
        assert str(result) == snippet
        assert result.find(lambda node: str(node) == WHITESPACE_KEYWORD)

        result = self.EBNF.parse(' "literal"', 'literal')
        assert result.error_flag  # literals catch following, but not leading whitespace


di68kap's avatar
di68kap committed
102
103


104
105
106
107
class TestPopRetrieve:
    mini_language = """
        document       = { text | codeblock }
        codeblock      = delimiter { text | (!:delimiter delimiter_sign) } ::delimiter
108
        delimiter      = delimiter_sign  # never use delimiter between capture and retrieve!!!
109
110
111
        delimiter_sign = /`+/
        text           = /[^`]+/ 
        """
112
    mini_lang2 = """
113
        @retrieve_counterpart = braces
114
        document       = { text | codeblock }
115
116
117
        codeblock      = braces { text | opening_braces | (!:braces closing_braces) } ::braces
        braces         = opening_braces
        opening_braces = /\{+/
118
        closing_braces = /\}+/
119
        text           = /[^{}]+/
120
        """
121
122
123

    def setup(self):
        self.minilang_parser = compileEBNF(self.mini_language)()
124
        self.minilang_parser2 = compileEBNF(self.mini_lang2)()
125

126
127
128
129
130
131
132
133
    @staticmethod
    def opening_delimiter(node, name):
        return node.tag_name == name and not isinstance(node.parser, Retrieve)

    @staticmethod
    def closing_delimiter(node):
        return isinstance(node.parser, Retrieve)

134
135
    def test_compile_mini_language(self):
        assert self.minilang_parser
136
        assert self.minilang_parser2
137
138
139
140
141

    def test_single_line(self):
        teststr = "Anfang ```code block `` <- keine Ende-Zeichen ! ``` Ende"
        syntax_tree = self.minilang_parser.parse(teststr)
        assert not syntax_tree.collect_errors()
142
143
        delim = str(next(syntax_tree.find(partial(self.opening_delimiter, name="delimiter"))))
        pop = str(next(syntax_tree.find(self.closing_delimiter)))
144
        assert delim == pop
145
146
147
148
149
150
151
152
153
154
155
156
157
158
        if WRITE_LOGS:
            syntax_tree.log("test_PopRetrieve_single_line", '.cst')

    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.parse(teststr)
        assert not syntax_tree.collect_errors()
159
160
        delim = str(next(syntax_tree.find(partial(self.opening_delimiter, name="delimiter"))))
        pop = str(next(syntax_tree.find(self.closing_delimiter)))
161
        assert delim == pop
162
163
        if WRITE_LOGS:
            syntax_tree.log("test_PopRetrieve_multi_line", '.cst')
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190

    def test_single_line_complement(self):
        teststr = "Anfang {{{code block }} <- keine Ende-Zeichen ! }}} Ende"
        syntax_tree = self.minilang_parser2.parse(teststr)
        assert not syntax_tree.collect_errors()
        delim = str(next(syntax_tree.find(partial(self.opening_delimiter, name="braces"))))
        pop = str(next(syntax_tree.find(self.closing_delimiter)))
        assert len(delim) == len(pop) and delim != pop
        if WRITE_LOGS:
            syntax_tree.log("test_PopRetrieve_single_line", '.cst')

    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.parse(teststr)
        assert not syntax_tree.collect_errors()
        delim = str(next(syntax_tree.find(partial(self.opening_delimiter, name="braces"))))
        pop = str(next(syntax_tree.find(self.closing_delimiter)))
        assert len(delim) == len(pop) and delim != pop
        if WRITE_LOGS:
            syntax_tree.log("test_PopRetrieve_multi_line", '.cst')
191
192


193
194
195
196
197
class TestSemanticValidation:
    def check(self, minilang, bool_filter=lambda x: x):
        grammar = EBNFGrammar()
        st = grammar.parse(minilang)
        assert not st.collect_errors()
198
        EBNFTransform(st)
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
        assert bool_filter(st.collect_errors())

    def test_illegal_nesting(self):
        self.check('impossible = { [ "an optional requirement" ] }')

    def test_illegal_nesting_option_required(self):
        self.check('impossible = [ §"an optional requirement" ]')

    def test_illegal_nesting_oneormore_option(self):
        self.check('impossible = { [ "no use"] }+')

    def test_legal_nesting(self):
        self.check('possible = { [ "+" ] "1" }', lambda x: not x)


class TestCompilerErrors:
    def test_error_propagation(self):
216
        ebnf = "@ literalws = wrongvalue  # testing error propagation\n"
217
        result, messages, st = full_compilation(ebnf, None, EBNFGrammar(), EBNFTransform,
218
219
220
221
                                                EBNFCompiler('ErrorPropagationTest'))
        assert messages


222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
class TestSelfHosting:
    def test_self(self):
        grammar = r"""
            # EBNF-Grammar in EBNF
            
            @ comment    =  /#.*(?:\n|$)/                    # comments start with '#' and eat all chars up to and including '\n'
            @ whitespace =  /\s*/                            # whitespace includes linefeed
            @ literalws  =  right                            # trailing whitespace of literals will be ignored tacitly
            
            syntax     =  [~//] { definition | directive } §EOF
            definition =  symbol §"=" expression
            directive  =  "@" §symbol §"=" ( regexp | literal | list_ )
            
            expression =  term { "|" term }
            term       =  { factor }+
            factor     =  [flowmarker] [retrieveop] symbol !"="   # negative lookahead to be sure it's not a definition
                        | [flowmarker] literal
                        | [flowmarker] regexp
                        | [flowmarker] group
                        | [flowmarker] regexchain
                        | [flowmarker] oneormore
                        | repetition
                        | option
            
            flowmarker =  "!"  | "&"  | "§" |                # '!' negative lookahead, '&' positive lookahead, '§' required
                          "-!" | "-&"                        # '-' negative lookbehind, '-&' positive lookbehind
            retrieveop =  "::" | ":"                         # '::' pop, ':' retrieve
            
            group      =  "(" expression §")"
            regexchain =  ">" expression §"<"                # compiles "expression" into a singular regular expression
            oneormore  =  "{" expression "}+"
            repetition =  "{" expression §"}"
            option     =  "[" expression §"]"
            
            link       = regexp | symbol | literal           # semantic restriction: symbol must evaluate to a regexp or chain
            
            symbol     =  /(?!\d)\w+/~                       # e.g. expression, factor, parameter_list
            literal    =  /"(?:[^"]|\\")*?"/~                # e.g. "(", '+', 'while'
                        | /'(?:[^']|\\')*?'/~                # whitespace following literals will be ignored tacitly.
            regexp     =  /~?\/(?:[^\/]|(?<=\\)\/)*\/~?/~    # e.g. /\w+/, ~/#.*(?:\n|$)/~
                                                             # '~' is a whitespace-marker, if present leading or trailing
                                                             # whitespace of a regular expression will be ignored tacitly.
            list_      =  /\w+/~ { "," /\w+/~ }              # comma separated list of symbols, e.g. BEGIN_LIST, END_LIST,
                                                             # BEGIN_QUOTE, END_QUOTE ; see CommonMark/markdown.py for an exmaple
            EOF =  !/./        
            """
        compiler_name = "EBNF"
        compiler = EBNFCompiler(compiler_name, grammar)
        parser = EBNFGrammar()
        result, errors, syntax_tree = full_compilation(grammar, None, parser,
                                                       EBNFTransform, compiler)
        assert not errors, str(errors)
        # compile the grammar again using the result of the previous
        # compilation as parser
        compileDSL(grammar, nil_scanner, result, EBNFTransform, compiler)



280
if __name__ == "__main__":
281
    from run import runner
282
    runner("", globals())