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author | Guido van Rossum <guido@python.org> | 1994-05-15 18:14:33 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 1994-05-15 18:14:33 (GMT) |
commit | 1d28e1707ab537289b6923b9b08482cf21b1d269 (patch) | |
tree | ca036ecd58277b16dcaf76fbe157a9390498e3e3 /Tools/scripts/pindent.py | |
parent | bc9231a3f6d68c9017f2a8ed7a90c14870da343f (diff) | |
download | cpython-1d28e1707ab537289b6923b9b08482cf21b1d269.zip cpython-1d28e1707ab537289b6923b9b08482cf21b1d269.tar.gz cpython-1d28e1707ab537289b6923b9b08482cf21b1d269.tar.bz2 |
Initial revision
Diffstat (limited to 'Tools/scripts/pindent.py')
-rwxr-xr-x | Tools/scripts/pindent.py | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/Tools/scripts/pindent.py b/Tools/scripts/pindent.py new file mode 100755 index 0000000..dfc3024 --- /dev/null +++ b/Tools/scripts/pindent.py @@ -0,0 +1,314 @@ +#! /ufs/guido/bin/sgi/python +#! /usr/local/bin/python + +# This file contains a class and a main program that perform two +# related (though complimentary) formatting operations on Python +# programs. When called as "pindend -c", it takes a valid Python +# program as input and outputs a version augmented with block-closing +# comments. When called as "pindent -r" it assumes its input is a +# Python program with block-closing comments but with its indentation +# messed up, and outputs a properly indented version. + +# A "block-closing comment" is a comment of the form '# end <keyword>' +# where <keyword> is the keyword that opened the block. If the +# opening keyword is 'def' or 'class', the function or class name may +# be repeated in the block-closing comment as well. Here is an +# example of a program fully augmented with block-closing comments: + +# def foobar(a, b): +# if a == b: +# a = a+1 +# elif a < b: +# b = b-1 +# if b > a: a = a-1 +# # end if +# else: +# print 'oops!' +# # end if +# # end def foobar + +# Note that only the last part of an if...elif...else... block needs a +# block-closing comment; the same is true for other compound +# statements (e.g. try...except). Also note that "short-form" blocks +# like the second 'if' in the example must be closed as well; +# otherwise the 'else' in the example would be ambiguous (remember +# that indentation is not significant when interpreting block-closing +# comments). + +# Both operations are idempotent (i.e. applied to their own output +# they yield an identical result). Running first "pindent -c" and +# then "pindent -r" on a valid Python program produces a program that +# is semantically identical to the input (though its indentation may +# be different). + +# Other options: +# -s stepsize: set the indentation step size (default 8) +# -t tabsize : set the number of spaces a tab character is worth (default 8) +# file ... : input file(s) (default standard input) +# The results always go to standard output + +# Caveats: +# - comments ending in a backslash will be mistaken for continued lines +# - continuations using backslash are always left unchanged +# - continuations inside parentheses are not extra indented by -r +# but must be indented for -c to work correctly (this breaks +# idempotency!) +# - continued lines inside triple-quoted strings are totally garbled + +# Secret feature: +# - On input, a block may also be closed with an "end statement" -- +# this is a block-closing comment without the '#' sign. + +# Possible improvements: +# - check syntax based on transitions in 'next' table +# - better error reporting +# - better error recovery +# - check identifier after class/def + +# The following wishes need a more complete tokenization of the source: +# - Don't get fooled by comments ending in backslash +# - reindent continuation lines indicated by backslash +# - handle continuation lines inside parentheses/braces/brackets +# - handle triple quoted strings spanning lines +# - realign comments +# - optionally do much more thorough reformatting, a la C indent + +import os +import regex +import string +import sys + +next = {} +next['if'] = next['elif'] = 'elif', 'else', 'end' +next['while'] = next['for'] = 'else', 'end' +next['try'] = 'except', 'finally' +next['except'] = 'except', 'else', 'end' +next['else'] = next['finally'] = next['def'] = next['class'] = 'end' +next['end'] = () +start = 'if', 'while', 'for', 'try', 'def', 'class' + +class PythonIndenter: + + def __init__(self, fpi = sys.stdin, fpo = sys.stdout, + indentsize = 8, tabsize = 8): + self.fpi = fpi + self.fpo = fpo + self.indentsize = indentsize + self.tabsize = tabsize + self.lineno = 0 + self.write = fpo.write + self.kwprog = regex.symcomp( + '^[ \t]*\(<kw>[a-z]+\)' + '\([ \t]+\(<id>[a-zA-Z_][a-zA-Z0-9_]*\)\)?' + '[^a-zA-Z0-9_]') + self.endprog = regex.symcomp( + '^[ \t]*#?[ \t]*end[ \t]+\(<kw>[a-z]+\)' + '\([ \t]+\(<id>[a-zA-Z_][a-zA-Z0-9_]*\)\)?' + '[^a-zA-Z0-9_]') + self.wsprog = regex.compile('^[ \t]*') + # end def __init__ + + def readline(self): + line = self.fpi.readline() + if line: self.lineno = self.lineno + 1 + # end if + return line + # end def readline + + def error(self, fmt, *args): + if args: fmt = fmt % args + # end if + sys.stderr.write('Error at line %d: %s\n' % (self.lineno, fmt)) + self.write('### %s ###\n' % fmt) + # end def error + + def getline(self): + line = self.readline() + while line[-2:] == '\\\n': + line2 = self.readline() + if not line2: break + # end if + line = line + line2 + # end while + return line + # end def getline + + def putline(self, line, indent = None): + if indent is None: + self.write(line) + return + # end if + tabs, spaces = divmod(indent*self.indentsize, self.tabsize) + i = max(0, self.wsprog.match(line)) + self.write('\t'*tabs + ' '*spaces + line[i:]) + # end def putline + + def reformat(self): + stack = [] + while 1: + line = self.getline() + if not line: break # EOF + # end if + if self.endprog.match(line) >= 0: + kw = 'end' + kw2 = self.endprog.group('kw') + if not stack: + self.error('unexpected end') + elif stack[-1][0] != kw2: + self.error('unmatched end') + # end if + del stack[-1:] + self.putline(line, len(stack)) + continue + # end if + if self.kwprog.match(line) >= 0: + kw = self.kwprog.group('kw') + if kw in start: + self.putline(line, len(stack)) + stack.append((kw, kw)) + continue + # end if + if next.has_key(kw) and stack: + self.putline(line, len(stack)-1) + kwa, kwb = stack[-1] + stack[-1] = kwa, kw + continue + # end if + # end if + self.putline(line, len(stack)) + # end while + if stack: + self.error('unterminated keywords') + for kwa, kwb in stack: + self.write('\t%s\n' % kwa) + # end for + # end if + # end def reformat + + def complete(self): + self.indentsize = 1 + stack = [] + todo = [] + current, firstkw, lastkw, topid = 0, '', '', '' + while 1: + line = self.getline() + i = max(0, self.wsprog.match(line)) + if self.endprog.match(line) >= 0: + thiskw = 'end' + endkw = self.endprog.group('kw') + thisid = self.endprog.group('id') + elif self.kwprog.match(line) >= 0: + thiskw = self.kwprog.group('kw') + if not next.has_key(thiskw): + thiskw = '' + # end if + if thiskw in ('def', 'class'): + thisid = self.kwprog.group('id') + else: + thisid = '' + # end if + elif line[i:i+1] in ('\n', '#'): + todo.append(line) + continue + else: + thiskw = '' + # end if + indent = len(string.expandtabs(line[:i], self.tabsize)) + while indent < current: + if firstkw: + if topid: + s = '# end %s %s\n' % ( + firstkw, topid) + else: + s = '# end %s\n' % firstkw + # end if + self.putline(s, current) + firstkw = lastkw = '' + # end if + current, firstkw, lastkw, topid = stack[-1] + del stack[-1] + # end while + if indent == current and firstkw: + if thiskw == 'end': + if endkw != firstkw: + self.error('mismatched end') + # end if + firstkw = lastkw = '' + elif not thiskw or thiskw in start: + if topid: + s = '# end %s %s\n' % ( + firstkw, topid) + else: + s = '# end %s\n' % firstkw + # end if + self.putline(s, current) + firstkw = lastkw = topid = '' + # end if + # end if + if indent > current: + stack.append(current, firstkw, lastkw, topid) + if thiskw and thiskw not in start: + # error + thiskw = '' + # end if + current, firstkw, lastkw, topid = \ + indent, thiskw, thiskw, thisid + # end if + if thiskw: + if thiskw in start: + firstkw = lastkw = thiskw + topid = thisid + else: + lastkw = thiskw + # end if + # end if + for l in todo: self.write(l) + # end for + todo = [] + if not line: break + # end if + self.write(line) + # end while + # end def complete + +# end class PythonIndenter + +def test(): + import getopt + opts, args = getopt.getopt(sys.argv[1:], 'crs:t:') + action = None + stepsize = 8 + tabsize = 8 + for o, a in opts: + if o == '-c': + action = PythonIndenter.complete + elif o == '-r': + action = PythonIndenter.reformat + elif p == '-s': + stepsize = string.atoi(a) + elif p == '-t': + tabsize = string.atoi(a) + # end if + # end for + if not action: + print 'You must specify -c(omplete) or -r(eformat)' + sys.exit(2) + # end if + if not args: args = ['-'] + # end if + for file in args: + if file == '-': + fp = sys.stdin + else: + fp = open(file, 'r') + # end if + pi = PythonIndenter(fp, sys.stdout, stepsize, tabsize) + action(pi) + if fp != sys.stdin: fp.close() + # end if + # end for +# end def test + +if __name__ == '__main__': + test() +# end if |