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怠惰なRubyistへの道 - Enumerator::Lazy の使いかた
nagachika
June 02, 2012
Technology
17
6.9k
怠惰なRubyistへの道 - Enumerator::Lazy の使いかた
みなとRuby会議01での発表「怠惰なRubyistへの道 - Enumerator::Lazy の使いかた」の発表資料を配布用に編集したものです。
nagachika
June 02, 2012
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Transcript
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&OVNFSBUPS-B[Z > Enumerator::Lazy.instance_methods(false) map collect flat_map collect_concat select find_all reject
grep zip take take_while drop drop_wihle cycle lazy force [ruby 2.0.0dev (2012-05-30 trunk 35844)] 37
GPSDF &OVNSBUPS-B[ZGPSDF UP@BͷBMJBT Ԇ͞Ε͍ͯΔΠςϨʔλͷධՁΛ࣮ߦ 38
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= l.map{|i| p i; i * 2 } => <Enumerator::Lazy: #<Enumerator::Lazy: 0..5>:map> # ͜ͷ࣌Ͱ·ͩϒϩοΫͷ༰࣮ߦ͞Ε͍ͯͳ͍! >> l_map.force 0 1 2 3 4 5 => [0, 2, 4, 6, 8, 10] # force ΛݺͿͱ࣮ߦ͞ΕΔ 39
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-B[Z$IBJO%FNP >> (0..4).lazy.select{|i| p “select:#{i}”; i.event? }.map{|i| p “map:#{i}”; i
* 2 }.force “select:0” “map:0” “select:1” “select:2” “map:2” “select:3” “select:4” “map:4” => [0, 4, 8] 58
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