Pluralize it!​​

Question

The challenge:

Write a program or function in any language that takes as an argument (command-line or function) a single English word. It returns or outputs the pluralized form of the word.

(To clarify, the program or function will be executed many times on different words, but separately - the list of words won't be passed all at once.)

The scoring:

The score of a program or function is -(characters in program + 1) * number of wrong answers. Highest score wins. Joke answers will likely lose by a huge margin (I'm planning on putting in maybe 1,000 words) and if you're amazing you get the highest score of 0.

Example test data:

woman
turn
fly
court
finger
blitz
pie
injury
vertex
alleyway
alloy
ox
goose
mouse
house
louse
waffle
right
bacterium
virus
cherub
chaetognath
boy
man
shaman
figure
prefix
etc.

Those are just some that I picked off the top of my head. The real test cases will have even stranger plurals, but the distribution between types of suffixes will be more even.

Enjoy!

Additional Rule

No Mathematica. Sorry.

Answer 1

sed, 6 chars

Someone should give this a try...

s/$/s/

Invoked with sed -f myscript.sed < words.txt > output.txt
I can afford 22 times more mistakes, compared to Gordon Bailey's solution, and still win.

With the sample input I do win, because he misses "mice" and "lice" (and maybe more, there are some I need to look up), and this sample is too short for me to have 44 mistakes...

Answer 2

require 'open-uri'

def p(w)
  open("http://en.wiktionary.org/wiki/#{w}"){|f| f.read}.match(/plural-form-of.*?title=\"(.*?)\"/)[1]
end

ruby at 135. It got all of the sample input (though it will eventually begin returning 403s if you type quickly enough).

Answer 3

sed - 155 (not including #! line)

#!/bin/sed -Ef
s/man$/men!/
s/([aeiou](x|z))$/\1es!/
s/ium$/ia!/
s/([^!aeiou])y$/\1ies!/
s/((r|gh|l|s)[^!aeiou])$/\1s!/
s/([^!aeiou]{2}|.s)$/\1es!/
s/([^!])$/\1s/
s/!$//

This will read from stdin, and I think it will do an okay job for most input. The basic idea is that it tries each regex line by line. Whenever it matches it makes a replacement that appends ! to make sure that no other regexes will match, then it drops the ! on the last line.

I tried to deal with most special cases, but it will definitely fail on some (goose and mouse for example)

Sample invocation:

chmod a+x GordonBailey.sed
echo $word | ./GordonBailey.sed

Answer 4

perl -mLingua::EN::Inflect=PL -pe's/.*/PL$&/e'

Answer 5

Extended BrainFuck: 9

,[.,]||s|

Compiling:

beef ebf.bf < plural.ebf > plural.bf

Turns into the following BrainFuck code: (39)

,[.,]>++++++++++[-<+++++++++++>]<+++++.

Sample invocation:

$ echo -n test | beef plural.bf

Any BrainFuck interpreter can be used instead of beef. It takes one word in stdin and ends it with EOF. Alternatively you can use echo test | bf -n plural.bf where in this particular interpreter-n assumes EOF on first linefeed.