1 What is DocTest
DocTest is a small program, that checks examples in Haskell comments. It is modeled after doctest for Python.
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)
satisfies the given examples:
$ doctest Fib.hs
Lines starting with
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.