filter

hugsでfilterを試してみる。

参考にしたページ
http://www.zvon.org/other/haskell/Outputprelude/filter_f.html

% hugs
__   __ __  __  ____   ___      _________________________________________
||   || ||  || ||  || ||__      Hugs 98: Based on the Haskell 98 standard
||___|| ||__|| ||__||  __||     Copyright (c) 1994-2005
||---||         ___||           World Wide Web: http://haskell.org/hugs
||   ||                         Bugs: http://hackage.haskell.org/trac/hugs
||   || Version: September 2006 _________________________________________

Haskell 98 mode: Restart with command line option -98 to enable extensions

Type :? for help
Hugs> filter(>5)[1,2,3,4,5,6,7,8,9,10]
[6,7,8,9,10]
Hugs> filter(>5)[1..10]
[6,7,8,9,10]
Hugs> filter(>'f')['a'..'z']
"ghijklmnopqrstuvwxyz"
Hugs> filter(>'f') $ filter(<'s')['a'..'z']
"ghijklmnopqr"
Hugs> filter(\x-> length(x) > 4)["hey","thank you", "hello world", "hola"]
["thank you","hello world"]
Hugs> filter(\x-> length(x) < 5)["hey","thank you", "hello world", "hola"]
["hey","hola"]
Hugs> filter(\x-> length(x) < 5)["hey","thank you", "hello world", "あ"]
["hey","\227\129\130"]
Hugs> filter(\x-> length(x) < 5)["hey","thank you", "hello world", "あれ"]
["hey"]