函数式编程

KakitChen

<span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 21px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="5" color="#800000">&nbsp; &nbsp; &nbsp; &nbsp;</font></span><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 21px; background-color: rgb(255, 255, 255); "><span class="Apple-style-span" style="line-height: 24px; "><font class="Apple-style-span" color="#800000" size="5">函数式编程</font></span></span></div><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 21px; background-color: rgb(255, 255, 255); ">&nbsp; &nbsp; &nbsp; &nbsp; <font class="Apple-style-span" size="4">函数式编程是种编程典范，它将电脑运算视为函数的计算。函数编程语言最重要的基础是 λ 演算（lambda calculus）。而且λ演算的函数可以接受函数当作输入（参数）和输出（返回值）。和指令式编程相比，函数式编程强调函数的计算比指令的执行重要。和过程化编程相比，函数式编程里，函数的计算可随时调用。</font></span></div><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 21px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="4"><br></font></span></div><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="4">虽然 λ 演算并非设计来于计算机上执行，但可视为第一个函数式编程语言。1980年代末期，Haskell发布，企图集合很多函数式编程研究里的想法。<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div></font></span><font class="Apple-style-span" color="#800000" size="5"><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); ">　</span><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); "><span class="headline-content">历史</span></span></font></div><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="4">　速度和空间上的顾虑<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　函数式编程常被认为严重耗费在CPU和内存资源。主因有二：<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　早期的函数式编程语言实现时并无考虑过效率问题。<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　非函数式编程语言为求提升速度，会在某些部分放弃边界检查或垃圾回收等功能。<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　缓式评估亦为语言如Haskell增加了额外的管理工作。<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　函数式编程语言<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　纯函数式的程序没有变量和副作用。<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　函数式编程经常使用递归。<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　纯函数式编程语言<div class="spctrl" style="height: 14px; line-height: 14px; overflow-x: hidden; overflow-y: hidden; "></div>　　因为纯函数式程式设计语言没有变量，函数没有副作用，编写出的程式可以利用memoization、common subexpression elimination和平行计算在运行时和编译时得到大量优化。</font></span></div><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="4">&nbsp; &nbsp; &nbsp; &nbsp;</font></span><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="4">函数式编程中最古老的例子莫过于1958年被创造出来的LISP了，透过 LISP，可以用精简的人力。较现代的例子包括Haskell、Clean、Erlang和Miranda等。</font></span></div><div><span class="Apple-style-span" style="font-family: arial, 宋体, sans-serif; line-height: 24px; background-color: rgb(255, 255, 255); "><font class="Apple-style-span" size="4"><br></font></span></div><div><span class="Apple-style-span" style="line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline" id=".E9.80.9F.E5.BA.A6.E5.92.8C.E7.A9.BA.E9.96.93.E4.B8.8A.E7.9A.84.E9.A1.A7.E6.85.AE" style="font-family: sans-serif; "><font class="Apple-style-span" color="#800000" size="5">速度和空间上的顾虑</font></span><p style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><font class="Apple-style-span" size="4" face="'Arial Narrow'">函数式编程常被认为严重耗费在CPU和存储器资源。主因有二：</font></p><ul style="line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="margin-bottom: 0.1em; "><font class="Apple-style-span" size="4" face="'Arial Narrow'">早期的函数式编程语言实现时并无考虑过效率问题。</font></li><li style="margin-bottom: 0.1em; "><font class="Apple-style-span" size="4" face="'Arial Narrow'">非函数式编程语言为求提升速度，会在某些部分放弃边界检查或垃圾回收等功能。</font></li></ul><p style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><font class="Apple-style-span" size="4" face="'Arial Narrow'"><font class="Apple-style-span" color="#000000"><font class="Apple-style-span" color="#000000"><a href="http://zh.wikipedia.org/wiki/%E6%83%B0%E6%80%A7%E6%B1%82%E5%80%BC" title="惰性求值" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#000000">惰性求值</font></a>亦为语言如<a href="http://zh.wikipedia.org/wiki/Haskell" title="Haskell" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#000000">Haskell</font></a></font>增加了额外的管理工作</font>。</font></p></span></div><div><font class="Apple-style-span" size="5" color="#800000"><span class="Apple-style-span" style="font-family: sans-serif; line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline"><br></span></span></font></div><div><font class="Apple-style-span" size="5" color="#800000"><span class="Apple-style-span" style="font-family: sans-serif; line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline" id=".E5.85.B8.E5.9E.8B.E7.9A.84.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80">典型的函数式编程语言</span></span></font></div><div><span class="Apple-style-span" style="font-family: 'Arial Narrow'; line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline" id=".E7.B4.94.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80"><font class="Apple-style-span" size="4"><b>纯函数式编程语言</b></font></span></span><span class="Apple-style-span" style="background-color: rgb(255, 255, 255); "><ul style="list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><font class="Apple-style-span" size="4"><li style="line-height: 1.5em; margin-bottom: 0.1em; "><font class="Apple-style-span" face="黑体">强静态类型</font><ul style="font-family: 'Arial Narrow'; line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/Concurrent_Clean" title="Concurrent Clean" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0">Concurrent Clean</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/Haskell" title="Haskell" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0">Haskell</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/w/index.php?title=Miranda&amp;action=edit&amp;redlink=1" class="new" title="Miranda（尚未撰写）" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0">Miranda</font></a></li></ul></li><li style="font-family: 'Arial Narrow'; margin-bottom: 0.1em; "><span class="Apple-style-span" style="line-height: 1.5em; ">弱类型</span><ul style="list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="line-height: 1.5em; margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/w/index.php?title=Lazy_K&amp;action=edit&amp;redlink=1" class="new" title="Lazy K（尚未撰写）" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0">Lazy K</font></a></li></ul></li></font></ul></span></div><div><span class="Apple-style-span" style="font-family: sans-serif; line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline" id=".E9.9D.9E.E7.B4.94.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80"><font class="Apple-style-span" size="4"><b>非纯函数式编程语言</b></font></span></span><span class="Apple-style-span" style="line-height: 22px; background-color: rgb(255, 255, 255); "><ul style="line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="margin-bottom: 0.1em; "><font class="Apple-style-span" face="'Arial Narrow'" size="4">强静态类型</font><ul style="line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/F" title="F" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">F#</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/ML%E8%AA%9E%E8%A8%80" title="ML语言" class="mw-redirect" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">ML</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/OCaml" title="OCaml" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">OCaml</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/Scala" title="Scala" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">Scala</font></a></li></ul></li><li style="margin-bottom: 0.1em; "><font class="Apple-style-span" size="4" face="'Arial Narrow'">强动态类型</font><ul style="line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/Erlang" title="Erlang" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">Erlang</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/LISP" title="LISP" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">LISP</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/LOGO" title="LOGO" class="mw-redirect" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">LOGO</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/Scheme" title="Scheme" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">Scheme</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/Mathematica" title="Mathematica" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">Mathematica</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/R%E8%AA%9E%E8%A8%80" title="R语言" class="mw-redirect" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" size="4" face="'Arial Narrow'" color="#0000f0">R</font></a></li></ul></li><li style="font-family: sans-serif; margin-bottom: 0.1em; "><font class="Apple-style-span" size="4">弱类型</font><ul style="font-size: 19px; line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; "><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/w/index.php?title=Unlambda&amp;action=edit&amp;redlink=1" class="new" title="Unlambda（尚未撰写）" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0">Unlambda</font></a></li></ul></li></ul><span class="editsection" style="float: right; margin-left: 1em; font-size: 15px; ">[<a href="http://zh.wikipedia.org/w/index.php?title=%E5%87%BD%E6%95%B8%E7%A8%8B%E5%BC%8F%E8%AA%9E%E8%A8%80&amp;action=edit&amp;section=5" title="编辑段落“其他函数式编程语言”" style="text-decoration: none; color: rgb(6, 69, 173); background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; background-position: initial initial; background-repeat: initial initial; " target="_blank" target="_blank">编辑</a>]</span></span><span class="Apple-style-span" style="font-family: sans-serif; line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline" id=".E5.85.B6.E4.BB.96.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80"><font class="Apple-style-span" size="4">其他函数式编程语言</font></span></span><span class="Apple-style-span" style="font-family: sans-serif; line-height: 22px; background-color: rgb(255, 255, 255); "><ul style="line-height: 1.5em; list-style-type: square; margin-top: 0.3em; margin-right: 0px; margin-bottom: 0px; margin-left: 1.5em; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; list-style-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAANCAMAAABW4lS6AAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAAZQTFRFAFKM////QIUK9QAAAAJ0Uk5T/wDltzBKAAAAGklEQVR42mJgBAEGokgGBjBGBxBxsBqAAAMACHwALd5r8ygAAAAASUVORK5CYII=); "><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/APL" title="APL" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0" size="4">APL</font></a></li><li style="margin-bottom: 0.1em; "><a href="http://zh.wikipedia.org/wiki/XSL_Transformations" title="XSL Transformations" class="mw-redirect" style="text-decoration: none; background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; " target="_blank" target="_blank"><font class="Apple-style-span" color="#0000f0" size="4">XSLT</font></a></li></ul></span><span class="Apple-style-span" style="font-family: sans-serif; font-size: 19px; font-weight: bold; line-height: 22px; background-color: rgb(255, 255, 255); "><span class="mw-headline" id=".E5.85.B6.E4.BB.96.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80"></span></span><span class="Apple-style-span" style="font-family: sans-serif; font-size: 20px; font-weight: bold; line-height: 22px; background-color: rgb(255, 255, 255); ">资料来源于</span><span class="Apple-style-span" style="font-family: sans-serif; font-size: 20px; font-weight: bold; line-height: 22px; background-color: rgb(255, 255, 255); ">:</span><a href="http://baike.baidu.com/view/1711147.htm" target="_blank" target="_blank">http://baike.baidu.com/view/1711147.htm</a></div><div><a href="http://zh.wikipedia.org/w/index.php?title=%E5%87%BD%E6%95%B8%E5%BC%8F%E7%B7%A8%E7%A8%8B&amp;variant=zh-cn#.E5.85.B6.E4.BB.96.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80" target="_blank" target="_blank">http://zh.wikipedia.org/w/index.php?title=%E5%87%BD%E6%95%B8%E5%BC%8F%E7%B7%A8%E7%A8%8B&amp;variant=zh-cn#.E5.85.B6.E4.BB.96.E5.87.BD.E6.95.B8.E5.BC.8F.E7.B7.A8.E7.A8.8B.E8.AA.9E.E8.A8.80</a></div><div><span class="Apple-style-span" style="font-family: sans-serif; font-size: 19px; font-weight: bold; line-height: 22px; background-color: rgb(255, 255, 255); "><div><br></div></span></div>