Haskell 几乎无疼痛入门指南
当他重装Linux机会虚拟机,安装haskell录制的过程中有什么。的方式来帮助那些谁在徘徊haskell进入外读者。基本概念:Haskell:是一门通用函数式语言。差点儿能够进行不论什么种类的开发,包含命令行,GUI,数据库,Web.源码能够跨平台:Linux,Mac,Windows,FreeBS...
haskell中的do
在haskell中,有一个do的语句专门用来做一些不那么“干净”的事情,比如读写都需要用do来开头一开始以为do的作用是做monad,后来发现是错误的,其实do做的事情是包裹一个顺序操作比如在如下代码中main=doif>thendoputStrLn"Step1"putStrLn"Step2"...
如何提高Haskell程序的性能?
I'mworkingthroughtheproblemsinProjectEulerasawayoflearningHaskell,andIfindthatmyprogramsarealotslowerthanacomparableCversion,evenwhencompiled.WhatcanI...
Haskell解析内存不足的大xml文件
So,I'veplayedaroundwithseveralHaskellXMLlibraries,includinghexpatandxml-enumerator.AfterreadingtheIOchapterinRealWorldHaskell(http://book.realworldhas...
在Haskell数据类型中键入类
InHaskell,onecandefineadatatypelikeso:在Haskell中,可以像这样定义数据类型:dataPoint1=Point1{x::Integer,y::Integer}Canoneusetypeclassesforvariablesinsideadatatype?If...
功能语言(Erlang,F#,Haskell,Scala)
1)Arefunctionallanguagessuitedforwebapplicationsdevelopment?1)功能语言是否适合Web应用程序开发?2)Arefunctionallanguagessuitedforbusiness/ERP/CRMtypeofapplications?2)...
Haskell中的“条件错误”
Myoriginalcodeisgivenbelowandworksfine.Iwantedtoaddrangecheckof'ind'andinthemodifiedversionIaddedanifstatement.WhenIrunitIgeta"typeerrorinconditional"...
在Haskell数据类型中键入类
InHaskell,onecandefineadatatypelikeso:在Haskell中,可以像这样定义数据类型:dataPoint1=Point1{x::Integer,y::Integer}Canoneusetypeclassesforvariablesinsideadatatype?If...
在Haskell中将字符串解析为另一种数据类型
RecentlyIhavebeentryingtocreateinHaskellaregexinterpretor.WhatIdidwascreateanewdatatypewithallpossibleconstructors(forsequence,*,^,intervals,etc)andth...
在haskell中定义多类型容器类,解决了绑定变量的问题
I'mhavingtroublewithclassesinhaskell.我在haskell的课上遇到麻烦。Basically,Ihaveanalgorithm(aweirdsortofgraph-traversalalgorithm)thattakesasinput,amongotherthing...
Haskell类型类和C ++模板类
IsitpossibletoemulatethetypeclassfunctionalityofHaskellwithC++(orC#)templates?是否可以使用C++(或C#)模板模拟Haskell的类型类功能?Doesitmakesenseoristhereanypayoffindoing...
“@”符号在引用Haskell中的列表时意味着什么?
I'vecomeacrossapieceofHaskellcodethatlookslikethis:我遇到了一段看起来像这样的Haskell代码:ps@(p:pt)Whatdoesthe@symbolmeaninthiscontext?Ican'tseemtofindanyinfoonGoogle...
输入' ='时Haskell错误解析错误
I'mnewtoHaskellandafterstartingghciItried:我是Haskell的新手,在开始ghci之后我尝试:fx=2*xandIobtained:我获得:<interactive>:1:4:parseerroroninput`='whichIdon'tunde...
何时在Haskell中利用类型推断?
I'mcuriousastohowoftenexperiencedHaskellprogrammersreallyusetypeinferenceinpractice.Ioftenseeitpraisedasanadvantageoverthealways-explicitdeclarationsn...
Haskell语言学习笔记(80)req
reqreq是一个好用,类型安全,可扩展,上层的HTTP客户端的库。$cabalinstallreqInstalledreq-1.1.0Prelude>:m+Network.HTTP.ReqPreludeNetwork.HTTP.Req>官方示例{-#LANGUAGEOverloaded...
haskell中的原始但有效的grep克隆?
WheneverIconsiderlearninganewlanguage--haskellinthiscase--Itrytohacktogetheraprimitivegrepclonetoseehowgoodthelanguageimplementationand/oritslibraries...
哪个haskell库会让我将2D数组/矢量保存到png / jpg / gif ...文件?
Iamplayingaroundwithhaskell,startingwithsimpleplottingprogramstowetmyfeet.Ineedalibrarythatwillletmesavea2Darray/vectortoanimagefile.Idon'twanttowrite...
Haskell中的并发数据库连接池
IamaJavaprogrammerwholearnsHaskell.Iworkonasmallweb-appthatusesHappstackandtalkstoadatabaseviaHDBC.我是一名学习Haskell的Java程序员。我在一个小型网络应用程序上工作,该应用程序使用Happst...
如何在Haskell中的父级和分叉子进程之间共享数据?
HowwouldIevengoaboutforkingachildprocessusingHaskellinthefirstplace?我怎么会首先使用Haskell来分配子进程呢?Also,ifpipesareanobvioussolutiontothedatasharingquestion-is...
是否有适合脚本编写的快速启动Haskell解释器?
Doesanyoneknowofaquick-startingHaskellinterpreterthatwouldbesuitableforuseinwritingshellscripts?Running'helloworld'usingHugstook400msonmyoldlaptopandt...