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Revision as of 12:03, 22 March 2009 by SimonHengel (talk | contribs) (fixed terminology)
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What is DocTest

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


Bellow is a small Haskell module. The module contains source code comments. Those comments are examples from an interactive Haskell session and demonstrate how the module is used.

module Fib where

-- Examples:
-- > fib 10
-- 55

-- > fib 5
-- 5

fib 0 = 0
fib 1 = 1
fib n = fib (n - 1) + fib (n - 2)

With DocTest you may checks if the implementation satisfies the given examples, by typing (on your Unix shell):

$ doctest Fib.hs

Lines starting with -- > denote expressions. All comment lines following an expression denote the result of that expression. Result is defined by what an REPL (e.g. ghci) prints to stdout and stderror when evaluating that expression.

DocTest on Hackage