syntaxtree.py 21.4 KB
Newer Older
1
"""syntaxtree.py - syntax tree classes for DHParser
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

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.
"""

Eckhart Arnold's avatar
Eckhart Arnold committed
19
import collections.abc
20
import copy
21
import os
22
23
from functools import partial

24
25
26
27
try:
    import regex as re
except ImportError:
    import re
28
29
30
31
32
33
try:
    from typing import AbstractSet, Any, ByteString, Callable, cast, Container, Dict, \
        Iterator, List, NamedTuple, Sequence, Union, Text, Tuple
except ImportError:
    from .typing34 import AbstractSet, Any, ByteString, Callable, cast, Container, Dict, \
        Iterator, List, NamedTuple, Sequence, Union, Text, Tuple
34

35
from DHParser.toolkit import is_logging, log_dir, StringView, linebreaks, line_col, identity
36

37
__all__ = ('WHITESPACE_PTYPE',
38
           'MockParser',
39
           'TOKEN_PTYPE',
Eckhart Arnold's avatar
Eckhart Arnold committed
40
           'ZOMBIE_PARSER',
Eckhart Arnold's avatar
Eckhart Arnold committed
41
           'ParserBase',
Eckhart Arnold's avatar
Eckhart Arnold committed
42
43
           'Error',
           'Node',
44
45
           'mock_syntax_tree',
           'TransformationFunc')
Eckhart Arnold's avatar
Eckhart Arnold committed
46
47


Eckhart Arnold's avatar
Eckhart Arnold committed
48
49
50
51
52
53
54
55
56
57
class ParserBase:
    """
    ParserBase is the base class for all real and mock parser classes.
    It is defined here, because Node objects require a parser object
    for instantiation.
    """
    def __init__(self, name=''):  # , pbases=frozenset()):
        self.name = name  # type: str
        self._ptype = ':' + self.__class__.__name__  # type: str

58
59
60
    def __repr__(self):
        return self.name + self.ptype

Eckhart Arnold's avatar
Eckhart Arnold committed
61
    def __str__(self):
62
        return self.name + (' = ' if self.name else '') + repr(self)
Eckhart Arnold's avatar
Eckhart Arnold committed
63
64
65
66
67

    @property
    def ptype(self) -> str:
        return self._ptype

68
69
70
    @property
    def repr(self) -> str:
        return self.name if self.name else repr(self)
Eckhart Arnold's avatar
Eckhart Arnold committed
71

72

73
74
75
76
WHITESPACE_PTYPE = ':Whitespace'
TOKEN_PTYPE = ':Token'


Eckhart Arnold's avatar
Eckhart Arnold committed
77
class MockParser(ParserBase):
78
79
    """
    MockParser objects can be used to reconstruct syntax trees from a
Eckhart Arnold's avatar
Eckhart Arnold committed
80
81
    serialized form like S-expressions or XML. Mock objects can mimic
    different parser types by assigning them a ptype on initialization.
82
83
84
85
86
    
    Mock objects should not be used for anything other than 
    syntax tree (re-)construction. In all other cases where a parser
    object substitute is needed, chose the singleton ZOMBIE_PARSER.
    """
Eckhart Arnold's avatar
Eckhart Arnold committed
87
    def __init__(self, name='', ptype=''):  # , pbases=frozenset()):
88
        assert not ptype or ptype[0] == ':'
Eckhart Arnold's avatar
Eckhart Arnold committed
89
        super(MockParser, self).__init__(name)
90
        self.name = name
Eckhart Arnold's avatar
Eckhart Arnold committed
91
        self._ptype = ptype or ':' + self.__class__.__name__
92
93
94


class ZombieParser(MockParser):
95
96
97
98
99
100
101
102
103
104
105
106
    """
    Serves as a substitute for a Parser instance.

    ``ZombieParser`` is the class of the singelton object
    ``ZOMBIE_PARSER``. The  ``ZOMBIE_PARSER`` has a name and can be
    called, but it never matches. It serves as a substitute where only
    these (or one of these properties) is needed, but no real Parser-
    object is instantiated.
    """
    alive = False

    def __init__(self):
107
        super(ZombieParser, self).__init__("__ZOMBIE__")
108
109
110
111
        assert not self.__class__.alive, "There can be only one!"
        assert self.__class__ == ZombieParser, "No derivatives, please!"
        self.__class__.alive = True

Eckhart Arnold's avatar
Eckhart Arnold committed
112
113
114
115
116
117
    def __copy__(self):
        return self

    def __deepcopy__(self, memo):
        return self

118
119
120
121
    def __call__(self, text):
        """Better call Saul ;-)"""
        return None, text

122
123
124
125

ZOMBIE_PARSER = ZombieParser()


126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
class Error:
    __slots__ = ['message', 'category', 'code', 'pos', 'line', 'column']

    ERROR = "error"
    WARNING = "warning"

    def __init__(self, message: str, category: str='', code: str=''):
        self.message = message
        self.category = category or Error.ERROR
        self.code = code
        self.pos = -1
        self.line = -1
        self.column = -1

    def __str__(self):
        return ("line: %3i, column: %2i" % (self.line, self.column)
                + ", %s: %s" % (self.category, self.message))

    @staticmethod
    def from_template(template: str, category: str='', content: Union[tuple, dict]=()):
        if isinstance(content, tuple):
            return Error(template % content, category, template)
        else:
            return Error(template.format(**content), category, template)

151

152
ChildrenType = Tuple['Node', ...]
153
154
StrictResultType = Union[ChildrenType, StringView, str]
ResultType = Union[ChildrenType, 'Node', StringView, str, None]
155
156


Eckhart Arnold's avatar
Eckhart Arnold committed
157
158
def flatten_sxpr(sxpr: str) -> str:
    """Returns S-expression `sxpr` as a one-liner without unnecessary
Eckhart Arnold's avatar
Eckhart Arnold committed
159
160
161
    whitespace.

    Example:
Eckhart Arnold's avatar
Eckhart Arnold committed
162
    >>> flatten_sxpr('(a\\n    (b\\n        c\\n    )\\n)\\n')
Eckhart Arnold's avatar
Eckhart Arnold committed
163
164
165
166
167
    '(a (b c))'
    """
    return re.sub('\s(?=\))', '', re.sub('\s+', ' ', sxpr)).strip()


Eckhart Arnold's avatar
Eckhart Arnold committed
168
class Node(collections.abc.Sized):
169
170
171
172
173
174
175
176
177
178
179
    """
    Represents a node in the concrete or abstract syntax tree.

    Attributes:
        tag_name (str):  The name of the node, which is either its
            parser's name or, if that is empty, the parser's class name
        result (str or tuple):  The result of the parser which
            generated this node, which can be either a string or a
            tuple of child nodes.
        children (tuple):  The tuple of child nodes or an empty tuple
            if there are no child nodes. READ ONLY!
180
181
182
183
184
185
        parser (Parser):  The parser which generated this node. 
            WARNING: In case you use mock syntax trees for testing or
            parser replacement during the AST-transformation: DO NOT
            rely on this being a real parser object in any phase after 
            parsing (i.e. AST-transformation and compiling), for 
            example by calling ``isinstance(node.parer, ...)``.
186
187
        errors (list):  A list of parser- or compiler-errors:
            tuple(position, string) attached to this node
Eckhart Arnold's avatar
Eckhart Arnold committed
188
189
        error_flag (bool):  True, if either the node or any of its
            descendants has errors.
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
        len (int):  The full length of the node's string result if the
            node is a leaf node or, otherwise, the concatenated string
            result's of its descendants. The figure always represents
            the length before AST-transformation ans will never change
            through AST-transformation. READ ONLY!
        pos (int):  the position of the node within the parsed text.

            The value of ``pos`` is -1 meaning invalid by default. 
            Setting this value will set the positions of all child
            nodes relative to this value.  

            To set the pos values of all nodes in a syntax tree, the
            pos value of the root node should be set to 0 right 
            after parsing.

            Other than that, this value should be considered READ ONLY. 
            At any rate, it should only be reassigned only during
            parsing stage and never during or after the
            AST-transformation.
    """
210

211
212
    __slots__ = ['_result', 'children', '_errors', '_len', '_pos', 'parser', 'error_flag']

213

Eckhart Arnold's avatar
Eckhart Arnold committed
214
    def __init__(self, parser, result: ResultType) -> None:
215
216
217
        """Initializes the ``Node``-object with the ``Parser``-Instance
        that generated the node and the parser's result.
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
218
        # self._result = ''  # type: StrictResultType
219
        # self.children = ()  # type: ChildrenType
220
        # self.error_flag = False  # type: bool
221
        self._errors = []  # type: List[Error]
222
        self.result = result
Eckhart Arnold's avatar
Eckhart Arnold committed
223
        self._len = len(self._result) if not self.children else \
224
            sum(child._len for child in self.children)  # type: int
Eckhart Arnold's avatar
Eckhart Arnold committed
225
        # self.pos: int  = 0  # continuous updating of pos values wastes a lot of time
226
        self._pos = -1  # type: int
227
228
        self.parser = parser or ZOMBIE_PARSER

Eckhart Arnold's avatar
Eckhart Arnold committed
229

230
231
    def __str__(self):
        if self.children:
232
            return "".join(str(child) for child in self.children)
233
234
        return str(self.result)

Eckhart Arnold's avatar
Eckhart Arnold committed
235

236
237
238
239
240
241
    def __repr__(self):
        mpargs = {'name': self.parser.name, 'ptype': self.parser.ptype}
        parg = "MockParser({name}, {ptype})".format(**mpargs)
        rarg = str(self) if not self.children else \
               "(" + ", ".join(repr(child) for child in self.children) + ")"
        return "Node(%s, %s)" % (parg, rarg)
242

Eckhart Arnold's avatar
Eckhart Arnold committed
243

244
245
246
247
248
249
250
251
252
    def __len__(self):
        return self._len


    def __bool__(self):
        # A node that is not None is always True, even if it's empty
        return True


253
    def __eq__(self, other):
254
255
        # return str(self.parser) == str(other.parser) and self.result == other.result
        return self.tag_name == other.tag_name and self.result == other.result
256

Eckhart Arnold's avatar
Eckhart Arnold committed
257

258
    def __hash__(self):
259
        return hash(self.tag_name)
260

Eckhart Arnold's avatar
Eckhart Arnold committed
261

262
263
264
265
266
267
    def __deepcopy__(self, memodict={}):
        result = copy.deepcopy(self.result)
        other = Node(self.parser, result)
        other._pos = self._pos
        return other

Eckhart Arnold's avatar
Eckhart Arnold committed
268

269
    @property   # this needs to be a (dynamic) property, in case sef.parser gets updated
270
    def tag_name(self) -> str:
271
        return self.parser.name or self.parser.ptype
272

Eckhart Arnold's avatar
Eckhart Arnold committed
273

274
    @property
Eckhart Arnold's avatar
Eckhart Arnold committed
275
    def result(self) -> StrictResultType:
276
277
278
        return self._result

    @result.setter
Eckhart Arnold's avatar
Eckhart Arnold committed
279
    def result(self, result: ResultType):
Eckhart Arnold's avatar
Eckhart Arnold committed
280
        # # made obsolete by static type checking with mypy
281
282
283
        # assert ((isinstance(result, tuple) and all(isinstance(child, Node) for child in result))
        #         or isinstance(result, Node)
        #         or isinstance(result, str)), str(result)
Eckhart Arnold's avatar
Eckhart Arnold committed
284
285
        # Possible optimization: Do not allow single nodes as argument:
        # assert not isinstance(result, Node)
286
        self._result = (result,) if isinstance(result, Node) else str(result) \
287
            if isinstance(result, StringView) else result or ''  # type: StrictResultType
288
        self.children = cast(ChildrenType, self._result) \
Eckhart Arnold's avatar
Eckhart Arnold committed
289
            if isinstance(self._result, tuple) else cast(ChildrenType, ())  # type: ChildrenType
290
        self.error_flag = any(r.error_flag for r in self.children)  # type: bool
291
292

    @property
293
    def pos(self) -> int:
294
295
296
297
        assert self._pos >= 0, "position value not initialized!"
        return self._pos

    @pos.setter
298
    def pos(self, pos: int):
299
300
        self._pos = pos
        offset = 0
301
        # recursively adjust pos-values of all children
302
303
        for child in self.children:
            child.pos = pos + offset
304
            offset += len(child)
305
306
307
        # add pos-values to Error-objects
        for err in self._errors:
            err.pos = pos
308

Eckhart Arnold's avatar
Eckhart Arnold committed
309

310
    @property
311
    def errors(self) -> List[Error]:
312
313
        return self._errors.copy()

314

315
316
317
318
319
    # def add_error(self, error_str: str) -> 'Node':
    #     assert isinstance(error_str, str)
    #     self._errors.append(error_str)
    #     self.error_flag = True
    #     return self
Eckhart Arnold's avatar
Eckhart Arnold committed
320

321
322
323
324
325
326
327
328
329
330

    def add_error(self: 'Node',
                  template: Union[str, Error],
                  category: str='',
                  content: Union[tuple, dict]=()) -> 'Node':
        if isinstance(template, Error):
            assert not (bool(category) or bool(content))
            self._errors.append(template)
        else:
            self._errors.append(Error.from_template(template, category, content))
Eckhart Arnold's avatar
Eckhart Arnold committed
331
332
333
        self.error_flag = True
        return self

Eckhart Arnold's avatar
Eckhart Arnold committed
334

335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
    def _finalize_errors(self, lbreaks: List[int]):
        if self.error_flag:
            for err in self._errors:
                assert err.pos >= 0
                err.line, err.column = line_col(lbreaks, err.pos)
            for child in self.children:
                child._finalize_errors(lbreaks)


    def finalize_errors(self, source_text: Union[StringView, str]):
        """Recursively adds line- and column-numbers to all error objects.
        """
        if self.error_flag:
            lbreaks = linebreaks(source_text)
            self._finalize_errors(lbreaks)


Eckhart Arnold's avatar
Eckhart Arnold committed
352
353
354
355
356
357
358
359
360
361
362
363
364
365
    def collect_errors(self, clear_errors=False) -> List[Error]:
        """
        Returns all errors of this node or any child node in the form
        of a set of tuples (position, error_message), where position
        is always relative to this node.
        """
        errors = self.errors
        if clear_errors:
            self._errors = []
            self.error_flag = False
        if self.children:
            for child in self.children:
                errors.extend(child.collect_errors(clear_errors))
        return errors
366

Eckhart Arnold's avatar
Eckhart Arnold committed
367

368
    def _tree_repr(self, tab, openF, closeF, dataF=identity, density=0) -> str:
369
370
371
372
373
374
375
376
        """
        Generates a tree representation of this node and its children
        in string from.

        The kind ot tree-representation that is determined by several
        function parameters. This could be an XML-representation or a
        lisp-like S-expression.

377
        Args:
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
            tab (str):  The indentation string, e.g. '\t' or '    '
            openF:  (Node->str) A function that returns an opening
                string (e.g. an XML-tag_name) for a given node
            closeF:  (Node->str) A function that returns a closeF
                string (e.g. an XML-tag_name) for a given node.
            dataF:  (str->str) A function that filters the data string
                before printing, e.g. to add quotation marks

        Returns (str):
            A string that contains a (serialized) tree representation
            of the node and its children.
        """
        head = openF(self)
        tail = closeF(self)

        if not self.result:
394
            return head.rstrip() + tail.lstrip()
395

396
        D = None if density & 2 else ''
397
398
399

        if self.children:
            content = []
400
            for child in self.children:
401
                subtree = child._tree_repr(tab, openF, closeF, dataF, density).split('\n')
402
                content.append('\n'.join((tab + s) for s in subtree))
403
            return head + '\n'.join(content) + tail.lstrip(D)
404

405
        res = cast(str, self.result)  # safe, because if there are no children, result is a string
406
407
408
409
        if density & 1 and res.find('\n') < 0:  # and head[0] == "<":
            # except for XML, add a gap between opening statement and content
            gap = ' ' if head.rstrip()[-1] != '>' else ''
            return head.rstrip() + gap + dataF(self.result) + tail.lstrip()
410
        else:
411
            return head + '\n'.join([tab + dataF(s) for s in res.split('\n')]) + tail.lstrip(D)
412

Eckhart Arnold's avatar
Eckhart Arnold committed
413

414
    def as_sxpr(self, src: str=None, compact: bool=False) -> str:
415
416
417
        """
        Returns content as S-expression, i.e. in lisp-like form.

418
        Args:
419
420
421
422
423
            src:  The source text or `None`. In case the source text is
                given the position of the element in the text will be
                reported as line and column.
        """

424
425
        lB, rB, D = ('', '', 1) if compact else ('(', '\n)', 0)

426
        def opening(node) -> str:
427
            s = lB + node.tag_name
428
429
            # s += " '(pos %i)" % node.pos
            if src:
Eckhart Arnold's avatar
Eckhart Arnold committed
430
                s += " '(pos %i " % node.pos + " %i %i)" % line_col(src, node.pos)
431
432
433
            if node.errors:
                s += " '(err '(%s))" % ' '.join(str(err).replace('"', r'\"')
                                                for err in node.errors)
434
            return s + '\n'
435
436
437
438
439
440

        def pretty(s):
            return '"%s"' % s if s.find('"') < 0 \
                else "'%s'" % s if s.find("'") < 0 \
                else '"%s"' % s.replace('"', r'\"')

441
        return self._tree_repr('    ', opening, lambda node: rB, pretty, density=D)
442

Eckhart Arnold's avatar
Eckhart Arnold committed
443

444
    def as_xml(self, src: str=None) -> str:
445
446
447
        """
        Returns content as XML-tree.

448
        Args:
449
450
451
452
453
            src:  The source text or `None`. In case the source text is
                given the position will also be reported as line and
                column.
        """

454
        def opening(node) -> str:
455
456
457
458
459
460
            s = '<' + node.tag_name
            # s += ' pos="%i"' % node.pos
            if src:
                s += ' line="%i" col="%i"' % line_col(src, node.pos)
            if node.errors:
                s += ' err="%s"' % ''.join(str(err).replace('"', r'\"') for err in node.errors)
461
            return s + ">\n"
462
463

        def closing(node):
464
            return '\n</' + node.tag_name + '>'
465

466
        return self._tree_repr('    ', opening, closing, density=1)
467

Eckhart Arnold's avatar
Eckhart Arnold committed
468

Eckhart Arnold's avatar
Eckhart Arnold committed
469
470
471
    def structure(self) -> str:
        """Return structure (and content) as S-expression on a single line
        without any line breaks."""
Eckhart Arnold's avatar
Eckhart Arnold committed
472
473
        return flatten_sxpr(self.as_sxpr())

474

Eckhart Arnold's avatar
Eckhart Arnold committed
475
    def content(self) -> str:
476
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
477
478
        Returns content as string, inserting error messages where
        errors occurred.
479
        """
Eckhart Arnold's avatar
Eckhart Arnold committed
480
481
482
483
        s = "".join(child.content() for child in self.children) if self.children \
            else str(self.result)
        return (
        ' <<< Error on "%s" | %s >>> ' % (s, '; '.join(self._errors))) if self._errors else s
484

Eckhart Arnold's avatar
Eckhart Arnold committed
485

486
    def find(self, match_function: Callable) -> Iterator['Node']:
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
        """Finds nodes in the tree that match a specific criterion.
        
        ``find`` is a generator that yields all nodes for which the
        given ``match_function`` evaluates to True. The tree is 
        traversed pre-order.
        
        Args:
            match_function (function): A function  that takes as Node
                object as argument and returns True or False
        Yields:
            Node: all nodes of the tree for which 
            ``match_function(node)`` returns True
        """
        if match_function(self):
            yield self
        else:
            for child in self.children:
                for nd in child.find(match_function):
                    yield nd

Eckhart Arnold's avatar
Eckhart Arnold committed
507

508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
    # def range(self, match_first, match_last):
    #     """Iterates over the range of nodes, starting from the first
    #     node for which ``match_first`` becomes True until the first node
    #     after this one for which ``match_last`` becomes true or until
    #     the end if it never does.
    #
    #     Args:
    #         match_first (function): A function  that takes as Node
    #             object as argument and returns True or False
    #         match_last (function): A function  that takes as Node
    #             object as argument and returns True or False
    #     Yields:
    #         Node: all nodes of the tree for which
    #         ``match_function(node)`` returns True
    #     """


525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
    # def navigate(self, path):
    #     """Yields the results of all descendant elements matched by
    #     ``path``, e.g.
    #     'd/s' yields 'l' from (d (s l)(e (r x1) (r x2))
    #     'e/r' yields 'x1', then 'x2'
    #     'e'   yields (r x1)(r x2)
    #
    #     Args:
    #         path (str):  The path of the object, e.g. 'a/b/c'. The
    #             components of ``path`` can be regular expressions
    #
    #     Returns:
    #         The object at the path, either a string or a Node or
    #         ``None``, if the path did not match.
    #     """
    #     def nav(node, pl):
    #         if pl:
    #             return itertools.chain(nav(child, pl[1:]) for child in node.children
    #                                    if re.match(pl[0], child.tag_name))
    #         else:
    #             return self.result,
    #     return nav(path.split('/'))
547

Eckhart Arnold's avatar
Eckhart Arnold committed
548

549
550
551
552
553
    def tree_size(self) -> int:
        """Recursively counts the number of nodes in the tree including the root node."""
        return sum(child.tree_size() for child in self.children) + 1


Eckhart Arnold's avatar
Eckhart Arnold committed
554
    def log(self, log_file_name):
555
        if is_logging():
Eckhart Arnold's avatar
Eckhart Arnold committed
556
557
558
559
            path = os.path.join(log_dir(), log_file_name)
            if os.path.exists(path):
                print('WARNING: Log-file "%s" already exists and will be overwritten!' % path)
            with open(path, "w", encoding="utf-8") as f:
560
                f.write(self.as_sxpr())
Eckhart Arnold's avatar
Eckhart Arnold committed
561

562

563
def mock_syntax_tree(sxpr):
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
    """
    Generates a tree of nodes from an S-expression.

    Example:
    >>> mock_syntax_tree("(a (b c))").as_sxpr()
    '(a\\n    (b\\n        "c"\\n    )\\n)'
    """

    def next_block(s):
        s = s.strip()
        while s[0] != ')':
            if s[0] != '(': raise ValueError('"(" expected, not ' + s[:10])
            # assert s[0] == '(', s
            level = 1
            i = 1
            while level > 0:
                if s[i] == '(':
                    level += 1
                elif s[i] == ')':
                    level -= 1
                i += 1
            yield s[:i]
            s = s[i:].strip()

588
589
590
591
592
593
594
595
596
    sxpr = sxpr.strip()
    if sxpr[0] != '(': raise ValueError('"(" expected, not ' + sxpr[:10])
    # assert sxpr[0] == '(', sxpr
    sxpr = sxpr[1:].strip()
    m = re.match('[\w:]+', sxpr)
    name, class_name = (sxpr[:m.end()].split(':') + [''])[:2]
    sxpr = sxpr[m.end():].strip()
    if sxpr[0] == '(':
        result = tuple(mock_syntax_tree(block) for block in next_block(sxpr))
597
598
    else:
        lines = []
599
        while sxpr and sxpr[0] != ')':
600
            for qm in ['"""', "'''", '"', "'"]:
601
                m = re.match(qm + r'.*?' + qm, sxpr, re.DOTALL)
602
603
                if m:
                    i = len(qm)
604
605
                    lines.append(sxpr[i:m.end() - i])
                    sxpr = sxpr[m.end():].strip()
606
607
                    break
            else:
608
609
610
                m = re.match(r'(?:(?!\)).)*', sxpr, re.DOTALL)
                lines.append(sxpr[:m.end()])
                sxpr = sxpr[m.end():]
611
612
613
614
        result = "\n".join(lines)
    return Node(MockParser(name, ':' + class_name), result)


615
TransformationFunc = Union[Callable[[Node], Any], partial]
616

617
618
619
620
621

# if __name__ == "__main__":
#     st = mock_syntax_tree("(alpha (beta (gamma i\nj\nk) (delta y)) (epsilon z))")
#     print(st.as_sxpr())
#     print(st.as_xml())