dsl.py 21 KB
Newer Older
1
"""dsl.py - Support for domain specific notations for DHParser
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

Copyright 2016  by Eckhart Arnold (arnold@badw.de)
                Bavarian Academy of Sciences an Humanities (badw.de)

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.

Module ``DSLsupport`` contains various functions to support the
compilation of domain specific languages based on an EBNF-grammar.
"""

import os
23

24
25
26
27
try:
    import regex as re
except ImportError:
    import re
28
29
30
31
try:
    from typing import Any, cast, Tuple, Union
except ImportError:
    from .typing34 import Any, cast, Tuple, Union
32

33
from DHParser.ebnf import EBNFCompiler, grammar_changed, \
34
35
    get_ebnf_preprocessor, get_ebnf_grammar, get_ebnf_transformer, get_ebnf_compiler, \
    PreprocessorFactoryFunc, ParserFactoryFunc, TransformerFactoryFunc, CompilerFactoryFunc
36
from DHParser.toolkit import logging, load_if_file, is_python_code, compile_python_object
37
from DHParser.parser import Grammar, Compiler, compile_source, nil_preprocessor, PreprocessorFunc
38
from DHParser.syntaxtree import Node, TransformationFunc
39

40
__all__ = ('GrammarError',
Eckhart Arnold's avatar
Eckhart Arnold committed
41
42
43
           'CompilationError',
           'load_compiler_suite',
           'compileDSL',
Eckhart Arnold's avatar
Eckhart Arnold committed
44
           'raw_compileEBNF',
45
           'compileEBNF',
46
           'grammar_provider',
47
           'compile_on_disk')
Eckhart Arnold's avatar
Eckhart Arnold committed
48
49


50
51
52
53
54
55
56
57
58
SECTION_MARKER = """\n
#######################################################################
#
# {marker}
#
#######################################################################
\n"""

RX_SECTION_MARKER = re.compile(SECTION_MARKER.format(marker=r'.*?SECTION.*?'))
59
RX_WHITESPACE = re.compile('\s*')
60
61

SYMBOLS_SECTION = "SYMBOLS SECTION - Can be edited. Changes will be preserved."
62
PREPROCESSOR_SECTION = "PREPROCESSOR SECTION - Can be edited. Changes will be preserved."
63
64
65
PARSER_SECTION = "PARSER SECTION - Don't edit! CHANGES WILL BE OVERWRITTEN!"
AST_SECTION = "AST SECTION - Can be edited. Changes will be preserved."
COMPILER_SECTION = "COMPILER SECTION - Can be edited. Changes will be preserved."
di68kap's avatar
di68kap committed
66
END_SECTIONS_MARKER = "END OF DHPARSER-SECTIONS"
67
68


69
DHPARSER_IMPORTS = '''
di68kap's avatar
di68kap committed
70
from functools import partial
Eckhart Arnold's avatar
Eckhart Arnold committed
71
import os
72
import sys
di68kap's avatar
di68kap committed
73
74
75
76
try:
    import regex as re
except ImportError:
    import re
77
78
from DHParser import logging, is_filename, load_if_file, \\
    Grammar, Compiler, nil_preprocessor, \\
79
    Lookbehind, Lookahead, Alternative, Pop, Required, Token, Synonym, \\
80
    Optional, NegativeLookbehind, OneOrMore, RegExp, Retrieve, Series, RE, Capture, \\
81
    ZeroOrMore, Forward, NegativeLookahead, mixin_comment, compile_source, \\
82
    last_value, counterpart, accumulate, PreprocessorFunc, \\
83
    Node, TransformationFunc, TransformationDict, TRUE_CONDITION, \\
84
    traverse, remove_children_if, merge_children, is_anonymous, \\
85
    reduce_single_child, replace_by_single_child, replace_or_reduce, remove_whitespace, \\
86
    remove_expendables, remove_empty, remove_tokens, flatten, is_whitespace, \\
87
    is_empty, is_expendable, collapse, replace_content, WHITESPACE_PTYPE, TOKEN_PTYPE, \\
88
89
    remove_parser, remove_content, remove_brackets, replace_parser, \\
    keep_children, is_one_of, has_content, apply_if, remove_first, remove_last
90
'''
di68kap's avatar
di68kap committed
91

92

Eckhart Arnold's avatar
Eckhart Arnold committed
93
DHPARSER_MAIN = '''
94
def compile_src(source):
95
96
    """Compiles ``source`` and returns (result, errors, ast).
    """
Eckhart Arnold's avatar
Eckhart Arnold committed
97
    with logging("LOGS"):
98
        compiler = get_compiler()
Eckhart Arnold's avatar
Eckhart Arnold committed
99
100
101
        cname = compiler.__class__.__name__
        log_file_name = os.path.basename(os.path.splitext(source)[0]) \\
            if is_filename(source) < 0 else cname[:cname.find('.')] + '_out'    
102
        result = compile_source(source, get_preprocessor(), 
103
104
                                get_grammar(),
                                get_transformer(), compiler)
Eckhart Arnold's avatar
Eckhart Arnold committed
105
106
    return result

107
108
109

if __name__ == "__main__":
    if len(sys.argv) > 1:
110
        result, errors, ast = compile_src(sys.argv[1])
111
112
113
        if errors:
            for error in errors:
                print(error)
114
            sys.exit(1)
115
        else:
116
            print(result.as_xml() if isinstance(result, Node) else result)
117
    else:
118
        print("Usage: {NAME}Compiler.py [FILENAME]")
119
120
'''

121

122
class GrammarError(Exception):
123
124
    """
    Raised when (already) the grammar of a domain specific language (DSL)
125
126
127
128
129
130
131
132
133
    contains errors.
    """

    def __init__(self, error_messages, grammar_src):
        self.error_messages = error_messages
        self.grammar_src = grammar_src


class CompilationError(Exception):
134
135
    """
    Raised when a string or file in a domain specific language (DSL)
136
137
    contains errors.
    """
138
    def __init__(self, error_messages, dsl_text, dsl_grammar, AST, result):
139
140
141
142
        self.error_messages = error_messages
        self.dsl_text = dsl_text
        self.dsl_grammar = dsl_grammar
        self.AST = AST
143
        self.result = result
144
145
146
147
148

    def __str__(self):
        return '\n'.join(self.error_messages)


149
def grammar_instance(grammar_representation) -> Tuple[Grammar, str]:
150
151
    """
    Returns a grammar object and the source code of the grammar, from
152
    the given `grammar`-data which can be either a file name, ebnf-code,
153
    python-code, a Grammar-derived grammar class or an instance of
154
155
    such a class (i.e. a grammar object already).
    """
156
    if isinstance(grammar_representation, str):
157
        # read grammar
158
        grammar_src = load_if_file(grammar_representation)
159
        if is_python_code(grammar_src):
160
161
            parser_py, errors, AST = grammar_src, '', None
        else:
Eckhart Arnold's avatar
Eckhart Arnold committed
162
163
            with logging(False):
                parser_py, errors, AST = compile_source(grammar_src, None,
Eckhart Arnold's avatar
Eckhart Arnold committed
164
                    get_ebnf_grammar(), get_ebnf_transformer(), get_ebnf_compiler())
165
        if errors:
166
            raise GrammarError('\n\n'.join(errors), grammar_src)
167
        parser_root = compile_python_object(DHPARSER_IMPORTS + parser_py, '\w+Grammar$')()
168
169
170
    else:
        # assume that dsl_grammar is a ParserHQ-object or Grammar class
        grammar_src = ''
171
        if isinstance(grammar_representation, Grammar):
172
            parser_root = grammar_representation
173
        else:
Eckhart Arnold's avatar
Eckhart Arnold committed
174
            # assume ``grammar_representation`` is a grammar class and get the root object
175
            parser_root = grammar_representation()
176
177
178
    return parser_root, grammar_src


179
def compileDSL(text_or_file: str,
180
               preprocessor: PreprocessorFunc,
181
               dsl_grammar: Union[str, Grammar],
182
               ast_transformation: TransformationFunc,
183
               compiler: Compiler) -> Any:
184
185
    """
    Compiles a text in a domain specific language (DSL) with an
186
187
    EBNF-specified grammar. Returns the compiled text or raises a
    compilation error.
188
189
    
    Raises:
190
        CompilationError if any errors occurred during compilation
191
192
    """
    assert isinstance(text_or_file, str)
193
    assert isinstance(compiler, Compiler)
Eckhart Arnold's avatar
Eckhart Arnold committed
194

195
    parser, grammar_src = grammar_instance(dsl_grammar)
196
    result, errors, AST = compile_source(text_or_file, preprocessor, parser,
Eckhart Arnold's avatar
Eckhart Arnold committed
197
198
199
                                         ast_transformation, compiler)
    if errors:
        src = load_if_file(text_or_file)
200
        raise CompilationError(errors, src, grammar_src, AST, result)
201
202
203
    return result


204
def raw_compileEBNF(ebnf_src: str, branding="DSL") -> EBNFCompiler:
205
206
    """
    Compiles an EBNF grammar file and returns the compiler object
Eckhart Arnold's avatar
Eckhart Arnold committed
207
    that was used and which can now be queried for the result as well
208
    as skeleton code for preprocessor, transformer and compiler objects.
Eckhart Arnold's avatar
Eckhart Arnold committed
209
210
211
212
213
214
215
216
217
218
219
220
221
    
    Args:
        ebnf_src(str):  Either the file name of an EBNF grammar or
            the EBNF grammar itself as a string.
        branding (str):  Branding name for the compiler suite source
            code. 
    Returns:
        An instance of class ``ebnf.EBNFCompiler``
    Raises:
        CompilationError if any errors occurred during compilation      
    """
    grammar = get_ebnf_grammar()
    compiler = get_ebnf_compiler(branding , ebnf_src)
222
223
    transformer = get_ebnf_transformer()
    compileDSL(ebnf_src, nil_preprocessor, grammar, transformer, compiler)
Eckhart Arnold's avatar
Eckhart Arnold committed
224
225
226
    return compiler


227
def compileEBNF(ebnf_src: str, branding="DSL") -> str:
228
229
    """
    Compiles an EBNF source file and returns the source code of a
230
    compiler suite with skeletons for preprocessor, transformer and
Eckhart Arnold's avatar
Eckhart Arnold committed
231
    compiler.
232
233
234
235

    Args:
        ebnf_src(str):  Either the file name of an EBNF grammar or
            the EBNF grammar itself as a string.
236
237
        branding (str):  Branding name for the compiler suite source
            code. 
238
    Returns:
239
        The complete compiler suite skeleton as Python source code.
240
241
    Raises:
        CompilationError if any errors occurred during compilation        
242
    """
Eckhart Arnold's avatar
Eckhart Arnold committed
243
    compiler = raw_compileEBNF(ebnf_src, branding)
244
245
    src = ["#/usr/bin/python\n",
           SECTION_MARKER.format(marker=SYMBOLS_SECTION), DHPARSER_IMPORTS,
246
           SECTION_MARKER.format(marker=PREPROCESSOR_SECTION), compiler.gen_preprocessor_skeleton(),
Eckhart Arnold's avatar
Eckhart Arnold committed
247
           SECTION_MARKER.format(marker=PARSER_SECTION), compiler.result,
248
249
250
           SECTION_MARKER.format(marker=AST_SECTION), compiler.gen_transformer_skeleton(),
           SECTION_MARKER.format(marker=COMPILER_SECTION), compiler.gen_compiler_skeleton(),
           SECTION_MARKER.format(marker=SYMBOLS_SECTION), DHPARSER_MAIN.format(NAME=branding)]
251
252
253
    return '\n'.join(src)


254
def grammar_provider(ebnf_src: str, branding="DSL") -> Grammar:
255
    """
256
    Compiles an EBNF grammar and returns a grammar-parser provider
257
258
259
260
261
262
263
264
265
    function for that grammar.

    Args:
        ebnf_src(str):  Either the file name of an EBNF grammar or
            the EBNF grammar itself as a string.
        branding (str or bool):  Branding name for the compiler
            suite source code. 
    
    Returns:
266
        A provider function for a grammar object for texts in the
267
268
        language defined by ``ebnf_src``.
    """
269
    grammar_src = compileDSL(ebnf_src, nil_preprocessor, get_ebnf_grammar(),
270
                             get_ebnf_transformer(), get_ebnf_compiler(branding))
271
    return compile_python_object(DHPARSER_IMPORTS + grammar_src, 'get_(?:\w+_)?grammar$')
272
273


274
def load_compiler_suite(compiler_suite: str) -> \
275
        Tuple[PreprocessorFactoryFunc, ParserFactoryFunc, TransformerFactoryFunc, CompilerFactoryFunc]:
276
277
    """
    Extracts a compiler suite from file or string ``compiler suite``
278
    and returns it as a tuple (preprocessor, parser, ast, compiler).
Eckhart Arnold's avatar
Eckhart Arnold committed
279
280
    
    Returns:
281
        4-tuple (preprocessor function, parser class, ast transformer function, compiler class)
282
283
284
285
286
287
    """
    global RX_SECTION_MARKER
    assert isinstance(compiler_suite, str)
    source = load_if_file(compiler_suite)
    if is_python_code(compiler_suite):
        try:
288
            intro, imports, preprocessor_py, parser_py, ast_py, compiler_py, outro = \
289
290
291
292
                RX_SECTION_MARKER.split(source)
        except ValueError as error:
            raise AssertionError('File "' + compiler_suite + '" seems to be corrupted. '
                                 'Please delete or repair file manually.')
293
        # TODO: Compile in one step and pick parts from namespace later ?
294
        preprocessor = compile_python_object(imports + preprocessor_py, 'get_(?:\w+_)?preprocessor$')
295
296
        parser = compile_python_object(imports + parser_py, 'get_(?:\w+_)?grammar$')
        ast = compile_python_object(imports + ast_py, 'get_(?:\w+_)?transformer$')
297
    else:
298
        # assume source is an ebnf grammar. Is there really any reasonable application case for this?
Eckhart Arnold's avatar
Eckhart Arnold committed
299
        with logging(False):
300
            compile_py, errors, AST = compile_source(source, None,
Eckhart Arnold's avatar
Eckhart Arnold committed
301
                get_ebnf_grammar(), get_ebnf_transformer(), get_ebnf_compiler())
302
303
        if errors:
            raise GrammarError('\n\n'.join(errors), source)
304
        preprocessor = get_ebnf_preprocessor
305
        parser = get_ebnf_grammar
306
        ast = get_ebnf_transformer
307
    compiler = compile_python_object(imports + compiler_py, 'get_(?:\w+_)?compiler$')
308

309
    return preprocessor, parser, ast, compiler
310
311


312
def is_outdated(compiler_suite: str, grammar_source: str) -> bool:
313
314
    """
    Returns ``True``  if the ``compile_suite`` needs to be updated.
315
316
317
318
319
320
321
     
    An update is needed, if either the grammar in the compieler suite 
    does not reflect the latest changes of ``grammar_source`` or if 
    sections from the compiler suite have diligently been overwritten
    with whitespace order to trigger their recreation. Note: Do not
    delete or overwrite the section marker itself. 

322
    Args:
323
324
325
326
327
328
329
330
331
        compiler_suite:  the parser class representing the grammar
            or the file name of a compiler suite containing the grammar
        grammar_source:  File name or string representation of the
            EBNF code of the grammar

    Returns (bool):
        True, if ``compiler_suite`` seems to be out of date.
    """
    try:
332
        preprocessor, grammar, ast, compiler = load_compiler_suite(compiler_suite)
333
        return grammar_changed(grammar(), grammar_source)
334
335
336
337
    except ValueError:
        return True


338
def run_compiler(text_or_file: str, compiler_suite: str) -> Any:
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
    """Compiles a source with a given compiler suite.

    Args:
        text_or_file (str):  Either the file name of the source code or
            the source code directly. (Which is determined by 
            heuristics. If ``text_or_file`` contains at least on
            linefeed then it is always assumed to be a source text and
            not a file name.)
        compiler_suite(str):  File name of the compiler suite to be
            used.
        
    Returns:
        The result of the compilation, the form and type of which 
        depends entirely on the compiler.
        
    Raises:
        CompilerError
    """
357
358
    preprocessor, parser, ast, compiler = load_compiler_suite(compiler_suite)
    return compileDSL(text_or_file, preprocessor(), parser(), ast(), compiler())
359
360


361
def compile_on_disk(source_file: str, compiler_suite="", extension=".xml"):
362
363
    """
    Compiles the a source file with a given compiler and writes the
364
365
    result to a file.

Eckhart Arnold's avatar
Eckhart Arnold committed
366
367
368
    If no ``compiler_suite`` is given it is assumed that the source
    file is an EBNF grammar. In this case the result will be a Python
    script containing a parser for that grammar as well as the
369
    skeletons for a preprocessor, AST transformation table, and compiler.
Eckhart Arnold's avatar
Eckhart Arnold committed
370
371
    If the Python script already exists only the parser name in the
    script will be updated. (For this to work, the different names
372
    need to be delimited section marker blocks.). `compile_on_disk()`
Eckhart Arnold's avatar
Eckhart Arnold committed
373
374
    returns a list of error messages or an empty list if no errors
    occurred.
375
376
377
378
379
    
    Parameters:
        source_file(str):  The file name of the source text to be
            compiled.
        compiler_suite(str):  The file name of the compiler suite
380
            (usually ending with 'Compiler.py'), with which the source
381
382
383
384
385
386
387
388
389
390
391
            file shall be compiled. If this is left empty, the source
            file is assumed to be an EBNF-Grammar that will be compiled
            with the internal EBNF-Compiler.
        extension(str):  The result of the compilation (if successful)
            is written to a file with the same name but a different
            extension than the source file. This parameter sets the
            extension.
            
    Returns:
        A list of error messages or an empty list if there were no 
        errors. 
Eckhart Arnold's avatar
Eckhart Arnold committed
392
    """
393
    filepath = os.path.normpath(source_file)
394
395
    # with open(source_file, encoding="utf-8") as f:
    #     source = f.read()
396
    rootname = os.path.splitext(filepath)[0]
397
    compiler_name = os.path.basename(rootname)
398
    if compiler_suite:
399
        sfactory, pfactory, tfactory, cfactory = load_compiler_suite(compiler_suite)
400
    else:
401
        sfactory = get_ebnf_preprocessor
402
403
        pfactory = get_ebnf_grammar
        tfactory = get_ebnf_transformer
404
        cfactory = get_ebnf_compiler
405
406
407
    compiler1 = cfactory()
    compiler1.set_grammar_name(compiler_name, source_file)
    result, errors, ast = compile_source(source_file, sfactory(), pfactory(), tfactory(), compiler1)
408
409
410
    if errors:
        return errors

411
    elif cfactory == get_ebnf_compiler:  # trans == get_ebnf_transformer or trans == EBNFTransformer:  # either an EBNF- or no compiler suite given
412
        ebnf_compiler = cast(EBNFCompiler, compiler1)
413
        global SECTION_MARKER, RX_SECTION_MARKER, PREPROCESSOR_SECTION, PARSER_SECTION, \
Eckhart Arnold's avatar
Eckhart Arnold committed
414
415
            AST_SECTION, COMPILER_SECTION, END_SECTIONS_MARKER, RX_WHITESPACE, \
            DHPARSER_MAIN, DHPARSER_IMPORTS
416
        f = None
417
        try:
418
            f = open(rootname + 'Compiler.py', 'r', encoding="utf-8")
419
            source = f.read()
420
            sections = RX_SECTION_MARKER.split(source)
421
            intro, imports, preprocessor, parser, ast, compiler, outro = sections
422
        except (PermissionError, FileNotFoundError, IOError) as error:
423
            intro, imports, preprocessor, parser, ast, compiler, outro = '', '', '', '', '', '', ''
424
        except ValueError as error:
425
426
427
            name = '"' + rootname + 'Compiler.py"'
            raise ValueError('Could not identify all required sections in ' + name +
                             '. Please delete or repair ' + name + ' manually!')
428
        finally:
429
430
431
            if f:
                f.close()
                f = None
432

433
434
435
        if RX_WHITESPACE.fullmatch(intro):
            intro = '#!/usr/bin/python'
        if RX_WHITESPACE.fullmatch(outro):
Eckhart Arnold's avatar
Eckhart Arnold committed
436
            outro = DHPARSER_MAIN.format(NAME=compiler_name)
437
438
        if RX_WHITESPACE.fullmatch(imports):
            imports = DHPARSER_IMPORTS
439
440
        if RX_WHITESPACE.fullmatch(preprocessor):
            preprocessor = ebnf_compiler.gen_preprocessor_skeleton()
441
        if RX_WHITESPACE.fullmatch(ast):
442
            ast = ebnf_compiler.gen_transformer_skeleton()
443
        if RX_WHITESPACE.fullmatch(compiler):
444
            compiler = ebnf_compiler.gen_compiler_skeleton()
445

446
        try:
447
            f = open(rootname + 'Compiler.py', 'w', encoding="utf-8")
448
449
            f.write(intro)
            f.write(SECTION_MARKER.format(marker=SYMBOLS_SECTION))
450
            f.write(imports)
451
452
            f.write(SECTION_MARKER.format(marker=PREPROCESSOR_SECTION))
            f.write(preprocessor)
453
            f.write(SECTION_MARKER.format(marker=PARSER_SECTION))
454
            f.write(result)
455
456
457
458
459
460
461
            f.write(SECTION_MARKER.format(marker=AST_SECTION))
            f.write(ast)
            f.write(SECTION_MARKER.format(marker=COMPILER_SECTION))
            f.write(compiler)
            f.write(SECTION_MARKER.format(marker=END_SECTIONS_MARKER))
            f.write(outro)
        except (PermissionError, FileNotFoundError, IOError) as error:
462
            print('# Could not write file "' + rootname + 'Compiler.py" because of: '
463
464
465
466
467
468
                  + "\n# ".join(str(error).split('\n)')))
            print(result)
        finally:
            if f:  f.close()

    else:
469
        f = None
470
471
472
        try:
            f = open(rootname + extension, 'w', encoding="utf-8")
            if isinstance(result, Node):
473
474
475
476
                if extension.lower() == '.xml':
                    f.write(result.as_xml())
                else:
                    f.write(result.as_sxpr())
477
478
479
480
481
482
483
484
485
486
            else:
                f.write(result)
        except (PermissionError, FileNotFoundError, IOError) as error:
            print('# Could not write file "' + rootname + '.py" because of: '
                  + "\n# ".join(str(error).split('\n)')))
            print(result)
        finally:
            if f:  f.close()

    return []
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528


def recompile_grammar(ebnf_filename, force=False) -> bool:
    """
    Recompiles an ebnf-grammar if necessary, that is, if either no
    corresponding 'XXXXCompiler.py'-file exists or if that file is
    outdated.

    Parameters:
        ebnf_filename(str):  The filename of the ebnf-source of the
            grammar. In case this is a directory and not a file, all
            files within this directory ending with .ebnf will be
            compiled.
        force(bool):  If False (default), the grammar will only be
            recompiled if it has been changed.
    """
    if os.path.isdir(ebnf_filename):
        success = True
        for entry in os.listdir(ebnf_filename):
            if entry.lower().endswith('.ebnf') and os.path.isfile(entry):
                success = success and recompile_grammar(entry, force)
        return success

    base, ext = os.path.splitext(ebnf_filename)
    compiler_name = base + 'Compiler.py'
    error_file_name = base + '_ebnf_ERRORS.txt'
    errors = []
    if (not os.path.exists(compiler_name) or force or
            grammar_changed(compiler_name, ebnf_filename)):
        # print("recompiling parser for: " + ebnf_filename)
        errors = compile_on_disk(ebnf_filename)
        if errors:
            # print("Errors while compiling: " + ebnf_filename + '!')
            with open(error_file_name, 'w') as f:
                for e in errors:
                    f.write(e)
                    f.write('\n')
            return False

    if not errors and os.path.exists(error_file_name):
        os.remove(error_file_name)
    return True