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。

Transcript

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19. "O&YBNQMF
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20. ͜͜·Ͱͷ·ͱΊ
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21. &OVNFSBUPS
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22. &OVNFSBUPS
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23. UP@FOVN FOVN@GPS
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30. XJUI@JOEFY
    

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32. ͜͜·Ͱͷ·ͱΊ
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33. &OVNFSBUPS-B[Z
    ͷ৽ػೳ
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34. &OVNFSBUPS-B[Z
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35. &OVNFSBCMFMB[Z
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36. &OVNFSBUPS-B[Z
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37. &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
    

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38. GPSDF
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    38
    

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39. "-B[Z%FNP
    >> l = (0..5).lazy
    =>
    >> l_map = l.map{|i| p i; i * 2 }
    => :map>
    # ͜ͷ࣌఺Ͱ͸·ͩϒϩοΫͷ಺༰͸࣮ߦ͞Ε͍ͯͳ͍!
    >> l_map.force
    0
    1
    2
    3
    4
    5
    => [0, 2, 4, 6, 8, 10]
    # force ΛݺͿͱ࣮ߦ͞ΕΔ
    39
    

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40. &OVNFSBUPSͱͷҧ͍
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    40
    

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41. 1JUGBMMPG
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42. 5SVF.FUIPE$IBJO
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43. 1JUGBMMPG
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44. 5SVF&YUFSOBM
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46. &OVNFSBCMFWFSTJPO
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    46
    

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47. &OVNFSBCMFWFSTJPO
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48. &OVNFSBCMFWFSTJPO
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49. &OVNFSBCMFWFSTJPO
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50. &OVNFSBCMFWFSTJPO
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51. -B[ZWFSTJPO
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53. -B[ZWFSTJPO
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54. -B[ZWFSTJPO
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55. -B[ZWFSTJPO
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56. -B[ZWFSTJPO
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57. -B[ZWFSTJPO
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58. -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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59. -B[ZXJUI*0
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    59
    

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60. -B[ZXJUI*0
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61. -B[Z-JTU
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62. 1JUGBMMPG-B[Z
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63. -B[ZBTB#FUUFS
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