summaryrefslogtreecommitdiffstats
path: root/Demo/parser/unparse.py
blob: bfb8a095eec81c053b8275f973bae93bc4745dec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
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
151
152
153
154
155
156
157
158
159
160
161
162
163
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
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
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
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
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
"Usage: unparse.py <path to source file>"
import sys
import _ast
import cStringIO
import os

def interleave(inter, f, seq):
    """Call f on each item in seq, calling inter() in between.
    """
    seq = iter(seq)
    try:
        f(seq.next())
    except StopIteration:
        pass
    else:
        for x in seq:
            inter()
            f(x)

class Unparser:
    """Methods in this class recursively traverse an AST and
    output source code for the abstract syntax; original formatting
    is disregarged. """

    def __init__(self, tree, file = sys.stdout):
        """Unparser(tree, file=sys.stdout) -> None.
         Print the source for tree to file."""
        self.f = file
        self._indent = 0
        self.dispatch(tree)
        print >>self.f,""
        self.f.flush()

    def fill(self, text = ""):
        "Indent a piece of text, according to the current indentation level"
        self.f.write("\n"+"    "*self._indent + text)

    def write(self, text):
        "Append a piece of text to the current line."
        self.f.write(text)

    def enter(self):
        "Print ':', and increase the indentation."
        self.write(":")
        self._indent += 1

    def leave(self):
        "Decrease the indentation level."
        self._indent -= 1

    def dispatch(self, tree):
        "Dispatcher function, dispatching tree type T to method _T."
        if isinstance(tree, list):
            for t in tree:
                self.dispatch(t)
            return
        meth = getattr(self, "_"+tree.__class__.__name__)
        meth(tree)


    ############### Unparsing methods ######################
    # There should be one method per concrete grammar type #
    # Constructors should be grouped by sum type. Ideally, #
    # this would follow the order in the grammar, but      #
    # currently doesn't.                                   #
    ########################################################

    def _Module(self, tree):
        for stmt in tree.body:
            self.dispatch(stmt)

    # stmt
    def _Expr(self, tree):
        self.fill()
        self.dispatch(tree.value)

    def _Import(self, t):
        self.fill("import ")
        interleave(lambda: self.write(", "), self.dispatch, t.names)

    def _ImportFrom(self, t):
        self.fill("from ")
        self.write(t.module)
        self.write(" import ")
        interleave(lambda: self.write(", "), self.dispatch, t.names)
        # XXX(jpe) what is level for?

    def _Assign(self, t):
        self.fill()
        for target in t.targets:
            self.dispatch(target)
            self.write(" = ")
        self.dispatch(t.value)

    def _AugAssign(self, t):
        self.fill()
        self.dispatch(t.target)
        self.write(" "+self.binop[t.op.__class__.__name__]+"= ")
        self.dispatch(t.value)

    def _Return(self, t):
        self.fill("return")
        if t.value:
            self.write(" ")
            self.dispatch(t.value)

    def _Pass(self, t):
        self.fill("pass")

    def _Break(self, t):
        self.fill("break")

    def _Continue(self, t):
        self.fill("continue")

    def _Delete(self, t):
        self.fill("del ")
        self.dispatch(t.targets)

    def _Assert(self, t):
        self.fill("assert ")
        self.dispatch(t.test)
        if t.msg:
            self.write(", ")
            self.dispatch(t.msg)

    def _Exec(self, t):
        self.fill("exec ")
        self.dispatch(t.body)
        if t.globals:
            self.write(" in ")
            self.dispatch(t.globals)
        if t.locals:
            self.write(", ")
            self.dispatch(t.locals)

    def _Print(self, t):
        self.fill("print ")
        do_comma = False
        if t.dest:
            self.write(">>")
            self.dispatch(t.dest)
            do_comma = True
        for e in t.values:
            if do_comma:self.write(", ")
            else:do_comma=True
            self.dispatch(e)
        if not t.nl:
            self.write(",")

    def _Global(self, t):
        self.fill("global ")
        interleave(lambda: self.write(", "), self.write, t.names)

    def _Yield(self, t):
        self.write("(")
        self.write("yield")
        if t.value:
            self.write(" ")
            self.dispatch(t.value)
        self.write(")")

    def _Raise(self, t):
        self.fill('raise ')
        if t.type:
            self.dispatch(t.type)
        if t.inst:
            self.write(", ")
            self.dispatch(t.inst)
        if t.tback:
            self.write(", ")
            self.dispatch(t.tback)

    def _TryExcept(self, t):
        self.fill("try")
        self.enter()
        self.dispatch(t.body)
        self.leave()

        for ex in t.handlers:
            self.dispatch(ex)
        if t.orelse:
            self.fill("else")
            self.enter()
            self.dispatch(t.orelse)
            self.leave()

    def _TryFinally(self, t):
        self.fill("try")
        self.enter()
        self.dispatch(t.body)
        self.leave()

        self.fill("finally")
        self.enter()
        self.dispatch(t.finalbody)
        self.leave()

    def _ExceptHandler(self, t):
        self.fill("except")
        if t.type:
            self.write(" ")
            self.dispatch(t.type)
        if t.name:
            self.write(", ")
            self.dispatch(t.name)
        self.enter()
        self.dispatch(t.body)
        self.leave()

    def _ClassDef(self, t):
        self.write("\n")
        self.fill("class "+t.name)
        if t.bases:
            self.write("(")
            for a in t.bases:
                self.dispatch(a)
                self.write(", ")
            self.write(")")
        self.enter()
        self.dispatch(t.body)
        self.leave()

    def _FunctionDef(self, t):
        self.write("\n")
        for deco in t.decorator_list:
            self.fill("@")
            self.dispatch(deco)
        self.fill("def "+t.name + "(")
        self.dispatch(t.args)
        self.write(")")
        self.enter()
        self.dispatch(t.body)
        self.leave()

    def _For(self, t):
        self.fill("for ")
        self.dispatch(t.target)
        self.write(" in ")
        self.dispatch(t.iter)
        self.enter()
        self.dispatch(t.body)
        self.leave()
        if t.orelse:
            self.fill("else")
            self.enter()
            self.dispatch(t.orelse)
            self.leave

    def _If(self, t):
        self.fill("if ")
        self.dispatch(t.test)
        self.enter()
        # XXX elif?
        self.dispatch(t.body)
        self.leave()
        if t.orelse:
            self.fill("else")
            self.enter()
            self.dispatch(t.orelse)
            self.leave()

    def _While(self, t):
        self.fill("while ")
        self.dispatch(t.test)
        self.enter()
        self.dispatch(t.body)
        self.leave()
        if t.orelse:
            self.fill("else")
            self.enter()
            self.dispatch(t.orelse)
            self.leave

    def _With(self, t):
        self.fill("with ")
        self.dispatch(t.context_expr)
        if t.optional_vars:
            self.write(" as ")
            self.dispatch(t.optional_vars)
        self.enter()
        self.dispatch(t.body)
        self.leave()

    # expr
    def _Str(self, tree):
        self.write(repr(tree.s))

    def _Name(self, t):
        self.write(t.id)

    def _Repr(self, t):
        self.write("`")
        self.dispatch(t.value)
        self.write("`")

    def _Num(self, t):
        self.write(repr(t.n))

    def _List(self, t):
        self.write("[")
        interleave(lambda: self.write(", "), self.dispatch, t.elts)
        self.write("]")

    def _ListComp(self, t):
        self.write("[")
        self.dispatch(t.elt)
        for gen in t.generators:
            self.dispatch(gen)
        self.write("]")

    def _GeneratorExp(self, t):
        self.write("(")
        self.dispatch(t.elt)
        for gen in t.generators:
            self.dispatch(gen)
        self.write(")")

    def _comprehension(self, t):
        self.write(" for ")
        self.dispatch(t.target)
        self.write(" in ")
        self.dispatch(t.iter)
        for if_clause in t.ifs:
            self.write(" if ")
            self.dispatch(if_clause)

    def _IfExp(self, t):
        self.write("(")
        self.dispatch(t.body)
        self.write(" if ")
        self.dispatch(t.test)
        self.write(" else ")
        self.dispatch(t.orelse)
        self.write(")")

    def _Dict(self, t):
        self.write("{")
        def writem((k, v)):
            self.dispatch(k)
            self.write(": ")
            self.dispatch(v)
        interleave(lambda: self.write(", "), writem, zip(t.keys, t.values))
        self.write("}")

    def _Tuple(self, t):
        self.write("(")
        if len(t.elts) == 1:
            (elt,) = t.elts
            self.dispatch(elt)
            self.write(",")
        else:
            interleave(lambda: self.write(", "), self.dispatch, t.elts)
        self.write(")")

    unop = {"Invert":"~", "Not": "not", "UAdd":"+", "USub":"-"}
    def _UnaryOp(self, t):
        self.write(self.unop[t.op.__class__.__name__])
        self.write("(")
        self.dispatch(t.operand)
        self.write(")")

    binop = { "Add":"+", "Sub":"-", "Mult":"*", "Div":"/", "Mod":"%",
                    "LShift":">>", "RShift":"<<", "BitOr":"|", "BitXor":"^", "BitAnd":"&",
                    "FloorDiv":"//", "Pow": "**"}
    def _BinOp(self, t):
        self.write("(")
        self.dispatch(t.left)
        self.write(" " + self.binop[t.op.__class__.__name__] + " ")
        self.dispatch(t.right)
        self.write(")")

    cmpops = {"Eq":"==", "NotEq":"!=", "Lt":"<", "LtE":"<=", "Gt":">", "GtE":">=",
                        "Is":"is", "IsNot":"is not", "In":"in", "NotIn":"not in"}
    def _Compare(self, t):
        self.write("(")
        self.dispatch(t.left)
        for o, e in zip(t.ops, t.comparators):
            self.write(" " + self.cmpops[o.__class__.__name__] + " ")
            self.dispatch(e)
            self.write(")")

    boolops = {_ast.And: 'and', _ast.Or: 'or'}
    def _BoolOp(self, t):
        self.write("(")
        s = " %s " % self.boolops[t.op.__class__]
        interleave(lambda: self.write(s), self.dispatch, t.values)
        self.write(")")

    def _Attribute(self,t):
        self.dispatch(t.value)
        self.write(".")
        self.write(t.attr)

    def _Call(self, t):
        self.dispatch(t.func)
        self.write("(")
        comma = False
        for e in t.args:
            if comma: self.write(", ")
            else: comma = True
            self.dispatch(e)
        for e in t.keywords:
            if comma: self.write(", ")
            else: comma = True
            self.dispatch(e)
        if t.starargs:
            if comma: self.write(", ")
            else: comma = True
            self.write("*")
            self.dispatch(t.starargs)
        if t.kwargs:
            if comma: self.write(", ")
            else: comma = True
            self.write("**")
            self.dispatch(t.kwargs)
        self.write(")")

    def _Subscript(self, t):
        self.dispatch(t.value)
        self.write("[")
        self.dispatch(t.slice)
        self.write("]")

    # slice
    def _Ellipsis(self, t):
        self.write("...")

    def _Index(self, t):
        self.dispatch(t.value)

    def _Slice(self, t):
        if t.lower:
            self.dispatch(t.lower)
        self.write(":")
        if t.upper:
            self.dispatch(t.upper)
        if t.step:
            self.write(":")
            self.dispatch(t.step)

    def _ExtSlice(self, t):
        interleave(lambda: self.write(', '), self.dispatch, t.dims)

    # others
    def _arguments(self, t):
        first = True
        nonDef = len(t.args)-len(t.defaults)
        for a in t.args[0:nonDef]:
            if first:first = False
            else: self.write(", ")
            self.dispatch(a)
        for a,d in zip(t.args[nonDef:], t.defaults):
            if first:first = False
            else: self.write(", ")
            self.dispatch(a),
            self.write("=")
            self.dispatch(d)
        if t.vararg:
            if first:first = False
            else: self.write(", ")
            self.write("*"+t.vararg)
        if t.kwarg:
            if first:first = False
            else: self.write(", ")
            self.write("**"+t.kwarg)

    def _keyword(self, t):
        self.write(t.arg)
        self.write("=")
        self.dispatch(t.value)

    def _Lambda(self, t):
        self.write("lambda ")
        self.dispatch(t.args)
        self.write(": ")
        self.dispatch(t.body)

    def _alias(self, t):
        self.write(t.name)
        if t.asname:
            self.write(" as "+t.asname)

def roundtrip(filename, output=sys.stdout):
    source = open(filename).read()
    tree = compile(source, filename, "exec", _ast.PyCF_ONLY_AST)
    Unparser(tree, output)



def testdir(a):
    try:
        names = [n for n in os.listdir(a) if n.endswith('.py')]
    except OSError:
        print >> sys.stderr, "Directory not readable: %s" % a
    else:
        for n in names:
            fullname = os.path.join(a, n)
            if os.path.isfile(fullname):
                output = cStringIO.StringIO()
                print 'Testing %s' % fullname
                try:
                    roundtrip(fullname, output)
                except Exception, e:
                    print '  Failed to compile, exception is %s' % repr(e)
            elif os.path.isdir(fullname):
                testdir(fullname)

def main(args):
    if args[0] == '--testdir':
        for a in args[1:]:
            testdir(a)
    else:
        for a in args:
            roundtrip(a)

if __name__=='__main__':
    main(sys.argv[1:])