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""" Indentation utilities for Cog.
http://nedbatchelder.com/code/cog
Copyright 2004-2009, Ned Batchelder.
"""
import re
def whitePrefix(strings):
""" Determine the whitespace prefix common to all non-blank lines
in the argument list.
"""
# Remove all blank lines from the list
strings = [s for s in strings if s.strip() != '']
if not strings: return ''
# Find initial whitespace chunk in the first line.
# This is the best prefix we can hope for.
prefix = re.match(r'\s*', strings[0]).group(0)
# Loop over the other strings, keeping only as much of
# the prefix as matches each string.
for s in strings:
for i in range(len(prefix)):
27 if prefix[i] != s[i]:
prefix = prefix[:i]
break
return prefix
def reindentBlock(lines, newIndent=''):
""" Take a block of text as a string or list of lines.
Remove any common whitespace indentation.
Re-indent using newIndent, and return it as a single string.
"""
if isinstance(lines, basestring):
lines = lines.split('\n')
oldIndent = whitePrefix(lines)
outLines = []
for l in lines:
if oldIndent:
l = l.replace(oldIndent, '', 1)
if l and newIndent:
l = newIndent + l
outLines.append(l)
return '\n'.join(outLines)
def commonPrefix(strings):
""" Find the longest string that is a prefix of all the strings.
"""
52 if not strings:
return ''
prefix = strings[0]
for s in strings:
if len(s) < len(prefix):
prefix = prefix[:len(s)]
if not prefix:
return ''
for i in range(len(prefix)):
if prefix[i] != s[i]:
prefix = prefix[:i]
break
return prefix
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