PHP Generatorまとめ

Transcript

1. 1)1
   δΣωϨʔλ·ͱΊ !SJHIUHP (PPE
   UP
   LOPX
   UIF
   1)1
   (FOFSBUPS
2. ໨࣍ w δΣωϨʔλͱ͸
   w ϝϦοτͱσϝϦοτ
   w ΍ͬͯΈΔɹͦͷ̍ɹδΣωϨʔλؔ਺
   w ΍ͬͯΈΔɹͦͷ̎ɹলϝϞϦ
   w ΍ͬͯΈΔɹͦͷ̏ɹTFOE
   w ·ͱΊ "
   UBCMF
   PG
   DPOUFOUT
3. δΣωϨʔλͱ͸ w δΣωϨʔλ͸ɺϓϩάϥϜʹ͓͍ͯɺ਺ྻͷ֤ཁ ૉͷ஋ͳͲΛ࣍ʑͱੜ੒ʢδΣωϨʔτʣ͠ଞͷख ଓ͖ʹ౉͢ɺͱ͍͏ػೳΛ͍࣋ͬͯΔखଓ͖Ͱ͋Δɻ w ஋Λ౉͢ํ๏ͱͯ͠͸ɺίʔϧόοΫͷΑ͏ʹͯ͠ଞ ͷखଓ͖ΛݺͿ΋ͷ΋͋Ε͹ɺݺͼग़͞ΕΔ౓ʹ࣍ʑ ͱҟͳΔ஋Λฦؔ͢਺Ͱ͋Δ͜ͱ΋͋Δɻ 8IBU
   JT
   (FOFSBUPS
4. δΣωϨʔλͱ͸ w δΣωϨʔλΛ࢖͑͹ɺγϯϓϧͳ
   ΠςϨʔλΛ ؆୯ʹ࣮૷Ͱ͖·͢ɻ
   *UFSBUPS
   ΠϯλʔϑΣΠε Λ࣮૷ͨ͠ΫϥεΛ༻ҙ͢Δ
   Φʔόʔϔου΍ෳ ࡶ͞Λ৺഑͢Δඞཁ͸͋Γ·ͤΜɻ 8IBU
   JT
   (FOFSBUPS
5. ✤ ϝϦοτ
   ✤ ΠςϨʔλ͕؆୯ʹͭ͘ΕΔʢγϯϓϧʹͳΔʣ
   ✤ লϝϞϦ
   ✤ σϝϦοτ
   ✤ લʹ͔͠ਐΊͳ͍ ϝϦοτͱσϝϦοτ (PPE
   BOE
   #BE
   QPJOU
6. w ೋ࣍ݩ഑ྻΛϧʔϓ ΍ͬͯΈΔ
   ͦͷ̍ &YBNQMF
   
7. <?php $reward_list = [ [13, 67, 23], // 1戦目の報酬 [2, 87, 30], // 2戦目の報酬 [85, 25, 41], // 3戦目の報酬 ]; // 普通の二次元ループ foreach ($reward_list as $rewards) { foreach ($rewards as $reward) { echo "\$reward -> $reward\n"; } } ΍ͬͯΈΔ
   ͦͷ̍ &YBNQMF
   
8. <?php $reward_list = [ [13, 67, 23], // 1戦目の報酬 [2, 87, 30], // 2戦目の報酬 [85, 25, 41], // 3戦目の報酬 ]; // ジェネレータ（を返す関数） function reward_generator($reward_list) { foreach ($reward_list as $rewards) { foreach ($rewards as $reward) { yield $reward; } } } foreach (reward_generator($reward_list) as $reward) { echo "\$reward -> $reward\n"; } ΍ͬͯΈΔ
   ͦͷ̍ &YBNQMF
   
9. ΍ͬͯΈΔ
   ͦͷ̍ &YBNQMF
    <?php // ジェネレータ（を返す関数） function reward_generator($reward_list) { foreach ($reward_list as $rewards) { foreach ($rewards as $reward) { yield $reward; } } } // 別パターン $g = reward_generator($reward_list); while ($g->valid()) { $reward = $g->current(); echo "\$reward -> $reward\n"; $g->next(); } ΠςϨʔλ
10. w େ͖ͳSBOHFͰ΋লϝϞϦʹΠςϨʔτ
    w IUUQQIQOFUNBOVBMKB MBOHVBHFHFOFSBUPSTPWFSWJFXQIQ ΍ͬͯΈΔ
    ͦͷ̎ &YBNQMF
    
11. <?php // 一気飲みパターン foreach (range(0, 1000000) as $val) { $sum += $val; } // ジェネレータ関数 function xrange($start, $end) { for ($i = $start; $i <= $end; $i++) { yield $i; } } foreach (xrange(0, 1000000) as $val) { $sum += $val; } ΍ͬͯΈΔ
    ͦͷ̎ &YBNQMF
     time: 0.2835 memory (byte): 144965632 time: 0.8537 memory (byte): 262144
12. w ZJFME͔Βͷฦ٫஋
    w (FOFSBUPSTFOE Λ࢖͏ ΍ͬͯΈΔ
    ͦͷ̏ &YBNQMF
    
13. ΍ͬͯΈΔ
    ͦͷ̏ &YBNQMF
     <?php function sum_generator($count) { $sum = 0; foreach (range(1, $count) as $i) { $sum += (yield $i); // 要括弧 } echo $sum; } $g = sum_generator(10); while ($g->valid()) { $num = $g->current(); $g->send($num * 2); // sendでyield自体の返り値とできる // $g->next(); // sendは自動的に進むのでnextしなくてよい }
14. ΍ͬͯΈΔ
    ͦͷ̏ &YBNQMF
     # Rubyなら def sum_generator(count) sum = 0 1.upto(count) do |i| sum += yield i end sum # 返り値 end sum = sum_generator(10){|i| i * 2}
15. ΍ͬͯΈΔ
    ͦͷ̏ &YBNQMF
     <?php function sum_generator($count) { $sum = 0; foreach (range(1, $count) as $i) { $sum += (yield $i); // 要括弧 } return $sum; } ... $sum = $g->getReturn(); // こうできたらいい • こうだったらいい • PHP7 RFC • https://wiki.php.net/rfc/generator-return-expressions
16. ·ͱΊ w δΣωϨʔλΛ࢖͏ͱΠςϨʔγϣϯ͕γϯϓϧʹ ͳΔ
    w ଎౓Λଟগ٘ਜ਼ʹͯ͠ɺϝϞϦΛઅ໿Ͱ͖Δ
    w ZJFMEͷฦΓ஋͸TFOEΛ࢖͏ $PODMVTJPOT
17. ͓ΘΓ