January 2014
Intermediate to advanced
352 pages
6h 34m
Japanese
Content preview from JavaScriptで学ぶ関数型プログラミング
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35
1.4 まとめ
次に、たとえば本書にこれまで登場したコードを、ビルトインの
Array#map
を使っ
て実装した場合にコードが動作しないことがありえます。可能性のある理由として
は、あなたが現在使っている動作環境にネイティブの
map
メソッドが実装されていな
いということが考えられます。クロスブラウザでの互換性がないために行き詰まると
いうことは、いかなる犠牲を払ってでも避けたいものです。このようなノイズは、そ
れ自体を認識することは重要ではありますが、関数型プログラミングを紹介するとい
うより大きな目的の前ではただの面倒に過ぎません。
Underscore
はこのようなノイ
ズをほとんど完全に排除します！
†
最後に、
JavaScript
はその言語特性から、プログラマが「車輪の再発明」をできる
機会が多く存在します。
JavaScript
自身は、パワフルな低レベルの構成要素と、中〜
高レベルの言語機能を持っていないことの完璧な配合を持っています。言語の進化は
（モジュールシステムのような）すでに存在する車輪の再発明の必要性を未然に防ぎ
ますが、言語機能を構築したいという欲求やその必要性を完全に取り去るものとは思
えません
††
。しかしながら、もし利用できる場合は、提供されているライブラリを
再利用すべきです
†††
。
Underscore
で提供されている機能を一から再実装すること
は面白い作業ではありますが、そのような作業は私自身（もしくは私の雇い主）やあ
なたにとって有益に働くことはないでしょう。
1.4
まとめ
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.