'''Pluralize English nouns (stage 2)

Command line usage:
$ python plural2.py noun
nouns
'''

import re

def match_sxz(noun):
    return re.search('[sxz]$', noun)

def apply_sxz(noun):
    return re.sub('$', 'es', noun)

def match_h(noun):
    return re.search('[^aeioudgkprt]h$', noun)

def apply_h(noun):
    return re.sub('$', 'es', noun)

def match_y(noun):
    return re.search('[^aeiou]y$', noun)
        
def apply_y(noun):
    return re.sub('y$', 'ies', noun)

def match_default(noun):
    return True

def apply_default(noun):
    return noun + 's'

rules = ((match_sxz, apply_sxz),
         (match_h, apply_h),
         (match_y, apply_y),
         (match_default, apply_default)
         )

def plural(noun):
    for matches_rule, apply_rule in rules:
        if matches_rule(noun):
            return apply_rule(noun)

if __name__ == '__main__':
    import sys
    if sys.argv[1:]:
        print(plural(sys.argv[1]))
    else:
        print(__doc__)

# Copyright (c) 2009, Mark Pilgrim, All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
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#   this list of conditions and the following disclaimer.
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#   and/or other materials provided with the distribution.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS'
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