source: python/trunk/Tools/scripts/pindent.py@ 391

Last change on this file since 391 was 391, checked in by dmik, 11 years ago

python: Merge vendor 2.7.6 to trunk.
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1#! /usr/bin/env python
2
3# This file contains a class and a main program that perform three
4# related (though complimentary) formatting operations on Python
5# programs. When called as "pindent -c", it takes a valid Python
6# program as input and outputs a version augmented with block-closing
7# comments. When called as "pindent -d", it assumes its input is a
8# Python program with block-closing comments and outputs a commentless
9# version. When called as "pindent -r" it assumes its input is a
10# Python program with block-closing comments but with its indentation
11# messed up, and outputs a properly indented version.
12
13# A "block-closing comment" is a comment of the form '# end <keyword>'
14# where <keyword> is the keyword that opened the block. If the
15# opening keyword is 'def' or 'class', the function or class name may
16# be repeated in the block-closing comment as well. Here is an
17# example of a program fully augmented with block-closing comments:
18
19# def foobar(a, b):
20# if a == b:
21# a = a+1
22# elif a < b:
23# b = b-1
24# if b > a: a = a-1
25# # end if
26# else:
27# print 'oops!'
28# # end if
29# # end def foobar
30
31# Note that only the last part of an if...elif...else... block needs a
32# block-closing comment; the same is true for other compound
33# statements (e.g. try...except). Also note that "short-form" blocks
34# like the second 'if' in the example must be closed as well;
35# otherwise the 'else' in the example would be ambiguous (remember
36# that indentation is not significant when interpreting block-closing
37# comments).
38
39# The operations are idempotent (i.e. applied to their own output
40# they yield an identical result). Running first "pindent -c" and
41# then "pindent -r" on a valid Python program produces a program that
42# is semantically identical to the input (though its indentation may
43# be different). Running "pindent -e" on that output produces a
44# program that only differs from the original in indentation.
45
46# Other options:
47# -s stepsize: set the indentation step size (default 8)
48# -t tabsize : set the number of spaces a tab character is worth (default 8)
49# -e : expand TABs into spaces
50# file ... : input file(s) (default standard input)
51# The results always go to standard output
52
53# Caveats:
54# - comments ending in a backslash will be mistaken for continued lines
55# - continuations using backslash are always left unchanged
56# - continuations inside parentheses are not extra indented by -r
57# but must be indented for -c to work correctly (this breaks
58# idempotency!)
59# - continued lines inside triple-quoted strings are totally garbled
60
61# Secret feature:
62# - On input, a block may also be closed with an "end statement" --
63# this is a block-closing comment without the '#' sign.
64
65# Possible improvements:
66# - check syntax based on transitions in 'next' table
67# - better error reporting
68# - better error recovery
69# - check identifier after class/def
70
71# The following wishes need a more complete tokenization of the source:
72# - Don't get fooled by comments ending in backslash
73# - reindent continuation lines indicated by backslash
74# - handle continuation lines inside parentheses/braces/brackets
75# - handle triple quoted strings spanning lines
76# - realign comments
77# - optionally do much more thorough reformatting, a la C indent
78
79from __future__ import print_function
80
81# Defaults
82STEPSIZE = 8
83TABSIZE = 8
84EXPANDTABS = False
85
86import io
87import re
88import sys
89
90next = {}
91next['if'] = next['elif'] = 'elif', 'else', 'end'
92next['while'] = next['for'] = 'else', 'end'
93next['try'] = 'except', 'finally'
94next['except'] = 'except', 'else', 'finally', 'end'
95next['else'] = next['finally'] = next['with'] = \
96 next['def'] = next['class'] = 'end'
97next['end'] = ()
98start = 'if', 'while', 'for', 'try', 'with', 'def', 'class'
99
100class PythonIndenter:
101
102 def __init__(self, fpi = sys.stdin, fpo = sys.stdout,
103 indentsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
104 self.fpi = fpi
105 self.fpo = fpo
106 self.indentsize = indentsize
107 self.tabsize = tabsize
108 self.lineno = 0
109 self.expandtabs = expandtabs
110 self._write = fpo.write
111 self.kwprog = re.compile(
112 r'^(?:\s|\\\n)*(?P<kw>[a-z]+)'
113 r'((?:\s|\\\n)+(?P<id>[a-zA-Z_]\w*))?'
114 r'[^\w]')
115 self.endprog = re.compile(
116 r'^(?:\s|\\\n)*#?\s*end\s+(?P<kw>[a-z]+)'
117 r'(\s+(?P<id>[a-zA-Z_]\w*))?'
118 r'[^\w]')
119 self.wsprog = re.compile(r'^[ \t]*')
120 # end def __init__
121
122 def write(self, line):
123 if self.expandtabs:
124 self._write(line.expandtabs(self.tabsize))
125 else:
126 self._write(line)
127 # end if
128 # end def write
129
130 def readline(self):
131 line = self.fpi.readline()
132 if line: self.lineno += 1
133 # end if
134 return line
135 # end def readline
136
137 def error(self, fmt, *args):
138 if args: fmt = fmt % args
139 # end if
140 sys.stderr.write('Error at line %d: %s\n' % (self.lineno, fmt))
141 self.write('### %s ###\n' % fmt)
142 # end def error
143
144 def getline(self):
145 line = self.readline()
146 while line[-2:] == '\\\n':
147 line2 = self.readline()
148 if not line2: break
149 # end if
150 line += line2
151 # end while
152 return line
153 # end def getline
154
155 def putline(self, line, indent):
156 tabs, spaces = divmod(indent*self.indentsize, self.tabsize)
157 i = self.wsprog.match(line).end()
158 line = line[i:]
159 if line[:1] not in ('\n', '\r', ''):
160 line = '\t'*tabs + ' '*spaces + line
161 # end if
162 self.write(line)
163 # end def putline
164
165 def reformat(self):
166 stack = []
167 while True:
168 line = self.getline()
169 if not line: break # EOF
170 # end if
171 m = self.endprog.match(line)
172 if m:
173 kw = 'end'
174 kw2 = m.group('kw')
175 if not stack:
176 self.error('unexpected end')
177 elif stack.pop()[0] != kw2:
178 self.error('unmatched end')
179 # end if
180 self.putline(line, len(stack))
181 continue
182 # end if
183 m = self.kwprog.match(line)
184 if m:
185 kw = m.group('kw')
186 if kw in start:
187 self.putline(line, len(stack))
188 stack.append((kw, kw))
189 continue
190 # end if
191 if next.has_key(kw) and stack:
192 self.putline(line, len(stack)-1)
193 kwa, kwb = stack[-1]
194 stack[-1] = kwa, kw
195 continue
196 # end if
197 # end if
198 self.putline(line, len(stack))
199 # end while
200 if stack:
201 self.error('unterminated keywords')
202 for kwa, kwb in stack:
203 self.write('\t%s\n' % kwa)
204 # end for
205 # end if
206 # end def reformat
207
208 def delete(self):
209 begin_counter = 0
210 end_counter = 0
211 while True:
212 line = self.getline()
213 if not line: break # EOF
214 # end if
215 m = self.endprog.match(line)
216 if m:
217 end_counter += 1
218 continue
219 # end if
220 m = self.kwprog.match(line)
221 if m:
222 kw = m.group('kw')
223 if kw in start:
224 begin_counter += 1
225 # end if
226 # end if
227 self.write(line)
228 # end while
229 if begin_counter - end_counter < 0:
230 sys.stderr.write('Warning: input contained more end tags than expected\n')
231 elif begin_counter - end_counter > 0:
232 sys.stderr.write('Warning: input contained less end tags than expected\n')
233 # end if
234 # end def delete
235
236 def complete(self):
237 stack = []
238 todo = []
239 currentws = thisid = firstkw = lastkw = topid = ''
240 while True:
241 line = self.getline()
242 i = self.wsprog.match(line).end()
243 m = self.endprog.match(line)
244 if m:
245 thiskw = 'end'
246 endkw = m.group('kw')
247 thisid = m.group('id')
248 else:
249 m = self.kwprog.match(line)
250 if m:
251 thiskw = m.group('kw')
252 if not next.has_key(thiskw):
253 thiskw = ''
254 # end if
255 if thiskw in ('def', 'class'):
256 thisid = m.group('id')
257 else:
258 thisid = ''
259 # end if
260 elif line[i:i+1] in ('\n', '#'):
261 todo.append(line)
262 continue
263 else:
264 thiskw = ''
265 # end if
266 # end if
267 indentws = line[:i]
268 indent = len(indentws.expandtabs(self.tabsize))
269 current = len(currentws.expandtabs(self.tabsize))
270 while indent < current:
271 if firstkw:
272 if topid:
273 s = '# end %s %s\n' % (
274 firstkw, topid)
275 else:
276 s = '# end %s\n' % firstkw
277 # end if
278 self.write(currentws + s)
279 firstkw = lastkw = ''
280 # end if
281 currentws, firstkw, lastkw, topid = stack.pop()
282 current = len(currentws.expandtabs(self.tabsize))
283 # end while
284 if indent == current and firstkw:
285 if thiskw == 'end':
286 if endkw != firstkw:
287 self.error('mismatched end')
288 # end if
289 firstkw = lastkw = ''
290 elif not thiskw or thiskw in start:
291 if topid:
292 s = '# end %s %s\n' % (
293 firstkw, topid)
294 else:
295 s = '# end %s\n' % firstkw
296 # end if
297 self.write(currentws + s)
298 firstkw = lastkw = topid = ''
299 # end if
300 # end if
301 if indent > current:
302 stack.append((currentws, firstkw, lastkw, topid))
303 if thiskw and thiskw not in start:
304 # error
305 thiskw = ''
306 # end if
307 currentws, firstkw, lastkw, topid = \
308 indentws, thiskw, thiskw, thisid
309 # end if
310 if thiskw:
311 if thiskw in start:
312 firstkw = lastkw = thiskw
313 topid = thisid
314 else:
315 lastkw = thiskw
316 # end if
317 # end if
318 for l in todo: self.write(l)
319 # end for
320 todo = []
321 if not line: break
322 # end if
323 self.write(line)
324 # end while
325 # end def complete
326# end class PythonIndenter
327
328# Simplified user interface
329# - xxx_filter(input, output): read and write file objects
330# - xxx_string(s): take and return string object
331# - xxx_file(filename): process file in place, return true iff changed
332
333def complete_filter(input = sys.stdin, output = sys.stdout,
334 stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
335 pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)
336 pi.complete()
337# end def complete_filter
338
339def delete_filter(input= sys.stdin, output = sys.stdout,
340 stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
341 pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)
342 pi.delete()
343# end def delete_filter
344
345def reformat_filter(input = sys.stdin, output = sys.stdout,
346 stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
347 pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)
348 pi.reformat()
349# end def reformat_filter
350
351def complete_string(source, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
352 input = io.BytesIO(source)
353 output = io.BytesIO()
354 pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)
355 pi.complete()
356 return output.getvalue()
357# end def complete_string
358
359def delete_string(source, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
360 input = io.BytesIO(source)
361 output = io.BytesIO()
362 pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)
363 pi.delete()
364 return output.getvalue()
365# end def delete_string
366
367def reformat_string(source, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
368 input = io.BytesIO(source)
369 output = io.BytesIO()
370 pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)
371 pi.reformat()
372 return output.getvalue()
373# end def reformat_string
374
375def make_backup(filename):
376 import os, os.path
377 backup = filename + '~'
378 if os.path.lexists(backup):
379 try:
380 os.remove(backup)
381 except os.error:
382 print("Can't remove backup %r" % (backup,), file=sys.stderr)
383 # end try
384 # end if
385 try:
386 os.rename(filename, backup)
387 except os.error:
388 print("Can't rename %r to %r" % (filename, backup), file=sys.stderr)
389 # end try
390# end def make_backup
391
392def complete_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
393 with open(filename, 'r') as f:
394 source = f.read()
395 # end with
396 result = complete_string(source, stepsize, tabsize, expandtabs)
397 if source == result: return 0
398 # end if
399 make_backup(filename)
400 with open(filename, 'w') as f:
401 f.write(result)
402 # end with
403 return 1
404# end def complete_file
405
406def delete_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
407 with open(filename, 'r') as f:
408 source = f.read()
409 # end with
410 result = delete_string(source, stepsize, tabsize, expandtabs)
411 if source == result: return 0
412 # end if
413 make_backup(filename)
414 with open(filename, 'w') as f:
415 f.write(result)
416 # end with
417 return 1
418# end def delete_file
419
420def reformat_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):
421 with open(filename, 'r') as f:
422 source = f.read()
423 # end with
424 result = reformat_string(source, stepsize, tabsize, expandtabs)
425 if source == result: return 0
426 # end if
427 make_backup(filename)
428 with open(filename, 'w') as f:
429 f.write(result)
430 # end with
431 return 1
432# end def reformat_file
433
434# Test program when called as a script
435
436usage = """
437usage: pindent (-c|-d|-r) [-s stepsize] [-t tabsize] [-e] [file] ...
438-c : complete a correctly indented program (add #end directives)
439-d : delete #end directives
440-r : reformat a completed program (use #end directives)
441-s stepsize: indentation step (default %(STEPSIZE)d)
442-t tabsize : the worth in spaces of a tab (default %(TABSIZE)d)
443-e : expand TABs into spaces (default OFF)
444[file] ... : files are changed in place, with backups in file~
445If no files are specified or a single - is given,
446the program acts as a filter (reads stdin, writes stdout).
447""" % vars()
448
449def error_both(op1, op2):
450 sys.stderr.write('Error: You can not specify both '+op1+' and -'+op2[0]+' at the same time\n')
451 sys.stderr.write(usage)
452 sys.exit(2)
453# end def error_both
454
455def test():
456 import getopt
457 try:
458 opts, args = getopt.getopt(sys.argv[1:], 'cdrs:t:e')
459 except getopt.error, msg:
460 sys.stderr.write('Error: %s\n' % msg)
461 sys.stderr.write(usage)
462 sys.exit(2)
463 # end try
464 action = None
465 stepsize = STEPSIZE
466 tabsize = TABSIZE
467 expandtabs = EXPANDTABS
468 for o, a in opts:
469 if o == '-c':
470 if action: error_both(o, action)
471 # end if
472 action = 'complete'
473 elif o == '-d':
474 if action: error_both(o, action)
475 # end if
476 action = 'delete'
477 elif o == '-r':
478 if action: error_both(o, action)
479 # end if
480 action = 'reformat'
481 elif o == '-s':
482 stepsize = int(a)
483 elif o == '-t':
484 tabsize = int(a)
485 elif o == '-e':
486 expandtabs = True
487 # end if
488 # end for
489 if not action:
490 sys.stderr.write(
491 'You must specify -c(omplete), -d(elete) or -r(eformat)\n')
492 sys.stderr.write(usage)
493 sys.exit(2)
494 # end if
495 if not args or args == ['-']:
496 action = eval(action + '_filter')
497 action(sys.stdin, sys.stdout, stepsize, tabsize, expandtabs)
498 else:
499 action = eval(action + '_file')
500 for filename in args:
501 action(filename, stepsize, tabsize, expandtabs)
502 # end for
503 # end if
504# end def test
505
506if __name__ == '__main__':
507 test()
508# end if
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