Fix Block Indentation TextMate Command

fix_block_indentation.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# TextMate command to correct block indentation for languages with 
# semantic whitespace (like Python or CoffeeScript).
# 
# Command settings:
#   input:      Selected Text or Document
#   output:     Replace Selected Text
#   activation: cmd+shift+R
#   scope:      source


from os import environ as ENV
import re

TM_SOFT_TABS = ENV.get('TM_SOFT_TABS', 'YES') == 'YES'
TM_TAB_SIZE  = int(ENV.get('TM_TAB_SIZE', 4))
TM_INDENT    = (TM_TAB_SIZE * ' ') if TM_SOFT_TABS else '\t'

INDENT_PAT = re.compile(r'^([ \t]*)(.+?\n)(\n+)(?=([ \t]+))', re.MULTILINE)
FORCE_INDENT_PAT = re.compile(r'^([ \t]*)(.+?\n)[ \t]*(\n+)(?=([ \t]+))', re.MULTILINE)
INC_INDENT_PAT = re.compile(r'[\'"]{3} |((class|def|elif|else|except|finally|for|if|try|with|while)\b.*:\s*$)')
DEC_INDENT_PAT = re.compile(r'(elif|else|except|finally)\b.*:')

def indenter(m):
    s = m.group(0)
    gs = (i1, line, gap, i2) = m.groups()
    
    # deal with indentation-change on preceeding line
    if INC_INDENT_PAT.match(line):
        i1 += TM_INDENT
    elif DEC_INDENT_PAT.match(line):
        i1 = il[0:-len(TM_INDENT)]
    
    indent = min(i1, i2)
    gap = gap.replace('\n', indent+'\n')
    return '{1}{2}{gap}'.format(s, *m.groups(), **locals())


def fix_block_indentation(txt, force_fix=False):
    PAT = FORCE_INDENT_PAT if force_fix else INDENT_PAT
    return PAT.subn(indenter, txt)[0]


if __name__ == '__main__':
    import sys, codecs, locale
    sys.stdin = codecs.open('/dev/stdin', 'rU', 'utf-8')
    sys.stdout = codecs.open('/dev/stdout', 'w', 'utf-8')
    
    force_fix = False
    if len(sys.argv) > 1 and sys.argv[1] == '-f':
        force_fix = True
    
    txt = sys.stdin.read()
    sys.stdout.write(fix_block_indentation(txt, force_fix=force_fix))