我在这里看到很多关于函数式语言的讨论。为什么你要使用传统语言而不是传统语言呢?他们在哪些方面做得更好?他们更不擅长什么?理想的函数式编程应用程序是什么?
当前回答
我不认为函数式编程方法“流行起来”有任何问题,因为它(作为一种编程风格)已经被使用了大约40年。每当OO程序员编写有利于不可变对象的干净代码时,这些代码就是借用了函数概念。
然而,这些天来,强制函数式风格的语言正在获得大量的虚拟墨水,这些语言是否会在未来占据主导地位是一个悬而未决的问题。我自己的怀疑是混合的、多范式的语言,如Scala或OCaml 将很可能统治“纯粹的”函数语言,就像纯粹的OO语言(Smalltalk、Beta等)影响了主流编程一样,但还没有成为最广泛使用的表示法。
最后,我忍不住要指出,你对FP的评论与我几年前从过程程序员那里听到的评论高度相似:
(恕我直言,这是神话)“普通”程序员不理解它。 这并没有被广泛教授。 任何你能用它来写的程序,都能用现有的技术以另一种方式来写。
Just as graphical user interfaces and "code as a model of the business" were concepts that helped OO become more widely appreciated, I believe that increased use of immutability and simpler (massive) parallelism will help more programmers see the benefits that the functional approach offers. But as much as we've learned in the past 50 or so years that make up the entire history of digital computer programming, I think we still have much to learn. Twenty years from now, programmers will look back in amazement at the primitive nature of the tools we're currently using, including the now-popular OO and FP languages.
其他回答
为什么函数式编程很重要
我要指出的是,你所说的关于函数式语言的一切,大约20年前,大多数人都在谈论面向对象语言。在那时候,OO是很常见的:
* The average corporate programmer, e.g. most of the people I work with, will not understand it and most work environments will not let you program in it
* It's not really taught at universities (or is it nowadays?)
* Most applications are simple enough to be solved in normal IMPERATIVE ways
改变必须来自某个地方。无论接受过早期技术培训的人是否认为变革没有必要,有意义的重要变革都会发生。尽管当时有很多人反对,但你认为向OO的转变是好的吗?
函数式编程将很可能成为工程师和科学家用来解决他们所面临的问题的工具。它不会像早期的语言那样占领世界。然而,最难打败的产品是Excel,如果我是一名工程师,需要做计算,Excel是很棒的。
However, F# is going to be another source and will likely fill design needs by the non-Computer Scientists. Let's face it, Computer Scientists have done a great job of creating a WHOLE new way of doing things. Object Oriented Programming is GREAT. But sometimes you just need a way to solve an equation, get a solution and graph it. That's it. Then a language like F# fills the bill. Or maybe you want to build a finite state machine, F# again could be one of the solutions, but then C could be a solution as well.
但是当涉及到并行处理时,Excel大放异彩,f#也会及时出现。但是要以友好的方式,F#= friendly。
我一直对“下一件大事”持怀疑态度。很多时候,下一个大事件纯粹是历史的偶然,无论技术好坏,它都在正确的时间出现在正确的地点。例如:c++, Tcl/Tk, Perl。所有的技术都是有缺陷的,都非常成功,因为它们被认为要么解决了当时的问题,要么与根深蒂固的标准几乎相同,或者两者兼而有之。函数式编程可能确实很棒,但这并不意味着它会被采用。
But I can tell you why people are excited about functional programming: many, many programmers have had a kind of "conversion experience" in which they discover that using a functional language makes them twice as productive (or maybe ten times as productive) while producing code that is more resilient to change and has fewer bugs. These people think of functional programming as a secret weapon; a good example of this mindset is Paul Graham's Beating the Averages. Oh, and his application? E-commerce web apps.
自2006年初以来,也有一些关于函数式编程和并行的讨论。因为像Simon Peyton Jones这样的人至少从1984年开始就一直在担心并行性,所以在函数式语言解决多核问题之前,我不会屏住呼吸。但它确实解释了目前一些额外的话题。
In general, American universities are doing a poor job teaching functional programming. There's a strong core of support for teaching intro programming using Scheme, and Haskell also enjoys some support there, but there's very little in the way of teaching advanced technique for functional programmer. I've taught such a course at Harvard and will do so again this spring at Tufts. Benjamin Pierce has taught such a course at Penn. I don't know if Paul Hudak has done anything at Yale. The European universities are doing a much better job; for example, functional programming is emphasized in important places in Denmark, the Netherlands, Sweden, and the UK. I have less of a sense of what's happening in Australasia.
我认为其中一个原因是有些人认为一门语言是否被接受最重要的部分是它有多好。不幸的是,事情很少这么简单。例如,我认为Python被接受的最大因素不是语言本身(尽管这非常重要)。Python如此受欢迎的最大原因是它庞大的标准库和更大的第三方库社区。
像Clojure或f#这样的语言可能是这个规则的例外,因为它们是构建在JVM/CLR之上的。因此,我没有答案。