# DocTest

### From HaskellWiki

Revision as of 11:35, 22 March 2009 by SimonHengel (Talk | contribs)

## Contents |

## 1 What is DocTest

DocTest is a small program, that checks examples in Haskell comments. It is modeled after doctest for Python.

## 2 Usage

Bellow is a small Haskell module with DocTest examples:

module Fib where -- Examples: -- -- > fib 10 -- 55 -- > fib 5 -- 5 fib 0 = 0 fib 1 = 1 fib n = fib (n - 1) + fib (n - 2)

fib

satisfies the given examples:

$ doctest Fib.hs

-- >

*expressions*.

All comment lines following an expression denote the
*result* of that expression, where result is defined by what a
REPL prints to standard output when evaluating that expression.

## 3 DocTest on Hackage

http://hackage.haskell.org/cgi-bin/hackage-scripts/package/DocTest