If you have the OverloadedStrings extension enabled you will need to give an explicit type to the annotation, e.g. {-# ANN myDef ("HLint: ignore" :: String) #-}. The ANN pragmas can also increase compile times or cause more recompilation than otherwise required, since they are ...
= 1) { System.err.println("Argument \"ON\" or \"OFF\" is required!"); System.exit(-1); } Light lamp = new Light(); Command switchUp = new FlipUpCommand(lamp); Command switchDown = new FlipDownCommand(lamp); Switch mySwitch = new Switch(); switch(arguments[0]) { case "ON...
type FilePath = Text But I didn't keep this because I found that in practice there aren't a lot of FilePath conversions required. shelly has toTextUnsafe/toTextWarn helpers for this. Can't easily set global variables. Some might say this is just upside, but for a straightforward script...
MultiParamTypeClassesare required for a large number of standard Haskell libraries, includingmtlandvector, and in many situations. Almost any project of non-trivial size must have this extension enabled somewhere, and if the code makes significant use ofmtl-style monad transformers or defines anythin...
The 4 computations have been calculated all in a single pass over the input list, and the results are free of the type constructors that are no longer required once the aggregation is complete. Another example of an Aggregation where we need to postprocess the result is counting the number ...
with-compiler: wasm32-wasi-ghc with-hc-pkg: wasm32-wasi-ghc-pkg source-repository-package type: git location: https://github.com/dmjio/miso branch: master if arch(wasm32) -- Required for TemplateHaskell. When using wasm32-wasi-cabal from -- ghc-wasm-meta, this is superseded by the ...
It should be a piece of cake to define a comonad instance for it:extractshould be a composition of(extract . extract)andduplicatea composition of(duplicate . fmap duplicate), right? It typechecks, so it must be right. But, just in case, like every good Haskell programmer, I decided to...
I quickly learned that this required a String to Int conversion, which I wanted to do safely (I didn’t want my program to blow up). Technically what I do is actually a String to Maybe Int conversion, as you can see in this code: How to use command line arguments in Haskell As ...
我真的看不出你为什么要在这里使用模式同义词;如果有疑问，我总是使用GADT构造函数作为in Ben's answer...
I never really tried to install a crosscompiler before. I think mostly because I was usually happy to make cross-compiler build at all: makingGHCbuild for a rare target usually required a patch or two. But one day I’ve decided to give full install a run. Original motivation was a bit...