Haskell Templates

There are templates for Haskell files and a Rakefile for processing Haskell files.

When you're finished, you'll have these rake commands:

• rake compile to compile all of the code.
• rake test to compile and run all the tests.
• rake clean to clean up unnecessary files (backups).
• rake clobber to clobber all files that can be regenerated (e.g., .hi and .o files.)

Haskell Files

You may find these templates handy when creating new Haskell files. Follow the instructions in the TODO comments, and then delete the comments.

This is for a new computation module.

module Module where

{- TODO: write the computation functions here -}

Test the computation functions in a test module.

module Main where

import Test.HUnit
import System
{- TODO: change the module name -}
import Module

{- TODO: Change the variable name.  Add more variables. -}
moduleTests = TestList [
  TestCase (assertEqual "write real test cases" 1 0)
  {- TODO: add more test cases -}
  ]

checkTests counts = case counts of
        Counts _ _ errors failures ->
                if (errors + failures > 0)
                then exitFailure
                else (exitWith ExitSuccess)

main = runTestTT
        (TestList [
          {- TODO: use test variables you've defined above -}
          TestLabel "templated variable of tests" moduleTests
          ])
       >>= checkTests

This is for a command-line driver. (These are very rare in my world.)

module Main where

import Data.String
import System.Environment
import System.Exit

{- TODO: import the appropriate modules -}
import Factorial

{- TODO: change "computation" to the computation you want to run on the
  command-line arguments -}
main = getArgs >>= putAnswers . (map computation) . parse

parse args     = map read args

putAnswers l   = putStr (unlines (map show l))

Rakefile

Each Haskell subfolder gets its own Rakefile:

def test_files
  # TODO: list all executable tests, without .hs!
  ["FactorialTest"]
end

def driver_files
  # TODO: list all executable drivers, without .hs!
  ["FactorialMain"]
end

load '../haskell.rake'

But it only works if you put this file in the _languages/haskell folder:

require 'rake/clean'

SRC = FileList['*.hs']
CLEAN.include('*~')
CLOBBER.include('*.hi', '*.o')
CLOBBER.include(test_files)
CLOBBER.include(driver_files)

task :default => :compile

task :compile do
  (test_files + driver_files).each do |f|
    system "ghc -O2 --make #{f}.hs"
  end
end

task :test => :compile do
  test_files.each do |f|
    system f
  end
end