| {-# OPTIONS_GHC -Wall -fno-warn-unused-binds #-} | |
| {-# LANGUAGE CPP #-} | |
| {-# LANGUAGE FlexibleContexts #-} | |
| {-# LANGUAGE IncoherentInstances #-} | |
| {-# LANGUAGE RankNTypes #-} | |
| {-# LANGUAGE ScopedTypeVariables #-} | |
| #if __GLASGOW_HASKELL__ >= 708 | |
| {-# LANGUAGE RoleAnnotations #-} | |
| #endif |
| {-# LANGUAGE CPP #-} | |
| {-# LANGUAGE FlexibleContexts #-} | |
| {-# LANGUAGE RankNTypes #-} | |
| {-# LANGUAGE ScopedTypeVariables #-} | |
| #if __GLASGOW_HASKELL__ >= 710 | |
| {-# LANGUAGE AllowAmbiguousTypes #-} | |
| #endif | |
| -- | Lightweight checked exceptions |
| // NuGet reference: WebSharper.Compiler | |
| open WebSharper | |
| type AR = IntelliFactory.Core.AssemblyResolution.AssemblyResolver | |
| module FE = WebSharper.Compiler.FrontEnd | |
| let compile (expr: Microsoft.FSharp.Quotations.Expr) : string option = | |
| let loader = FE.Loader.Create (AR.Create()) (eprintfn "%O") | |
| let options = | |
| { FE.Options.Default with |
| case class Circle(radius: Double) { | |
| def area = radius * radius * Math.PI | |
| } | |
| case class Rectangle(side: Double) { | |
| def area = side * side | |
| } | |
| case class Triangle(base: Double, height: Double) { | |
| def area = 0.5d * base * height |
It's like creating the front end and back end of a compiler inside Haskell without the need of Template Haskell!
Write your DSL AST as a Free Monad, and then interpret the monad any way you like.
The advantage is that you get to swap out your interpreter, and your main code
| {------------------------------------------------------------------------------- | |
| Discussion of ContT in terms of callbacks | |
| For an alternative exposition, see | |
| <http://www.haskellforall.com/2012/12/the-continuation-monad.html>. | |
| -------------------------------------------------------------------------------} | |
| {-# OPTIONS_GHC -Wall #-} | |
| import Control.Exception |
| {-# LANGUAGE OverloadedStrings, RankNTypes, ScopedTypeVariables, | |
| NoMonomorphismRestriction, DeriveDataTypeable #-} | |
| module Main where | |
| import Prelude hiding (and, catch) | |
| import Data.Char (toLower) | |
| import Data.Conduit | |
| import Data.Conduit.Util | |
| import Data.Conduit.ImageSize (sinkImageInfo) | |
| import Data.Conduit.Binary (sourceFile, conduitFile, sinkFile) |
| using System; | |
| using System.Diagnostics; | |
| using System.IO; | |
| using System.Threading; | |
| using System.Threading.Tasks; | |
| namespace Test | |
| { | |
| class Program | |
| { |
| import Control.Monad | |
| import Data.List | |
| import Test.HUnit | |
| readMaybe :: (Read a) => String -> Maybe a | |
| readMaybe st = case reads st of [(x, "")] -> Just x | |
| _ -> Nothing | |
| foldingFunction :: [Double] -> String -> Maybe [Double] | |
| foldingFunction (x:y:ys) "*" = return $ (y * x) : ys |
