Determine if a string is collapsible: Difference between revisions

=={{header|Haskell}}==

<lang haskell>

import Text.Printf

main :: IO ()

main = do

mapM_ (\t -> printf "old: %d «««%s»»»\nnew: %d «««%s»»»\n" (length $ fst t) (fst t) (length $ snd t) (snd t)) $ map (\s -> (s, strip s)) input

where input = [ ""

, "The better the 4-wheel drive, the further you'll be from help when ya get stuck!"

, "headmistressship"

, "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "

, "..1111111111111111111111111111111111111111111111111111111111111117777888"

, "I never give 'em hell, I just tell the truth, and they think it's hell. "

, " --- Harry S Truman "

]

strip s = filter (/='😀') . snd . unzip . filter (\t@(a, b) -> a /= b) $ zip ('😀' : s) (s <> ['😀'])

</lang>

{{out}}

<pre>

old: 0 «««»»»

new: 0 «««»»»

old: 80 «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»»

new: 77 «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»»

old: 16 «««headmistressship»»»

new: 14 «««headmistreship»»»

old: 72 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»»

new: 70 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»»

old: 72 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»»

new: 4 «««.178»»»

old: 72 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»»

new: 69 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»»

old: 72 ««« --- Harry S Truman »»»

new: 17 ««« - Hary S Truman »»»

</pre>