Copyright	(c) Simon Marlow 2002
License	BSD-style
Maintainer	libraries@haskell.org
Stability	provisional
Portability	portable
Safe Haskell	Safe-Inferred

Test

Contents

Description

This module illustrates & tests most of the features of Haddock. Testing references from the description: T, f, g, visible.

Synopsis

Type declarations

Data types

data T a b

This comment applies to the following declaration and it continues until the next non-comment line

Constructors

A Int (Maybe Float)	This comment describes the `A` constructor
B (T a b, T Int Float)	This comment describes the `B` constructor

data T2 a b

An abstract data declaration

data T3 a b

A data declaration with no documentation annotations on the constructors

Constructors

A1 a
B1 b

data T4 a b

Constructors

A2 a
B2 b

data T5 a b

Constructors

A3 a	documents `A3`
B3 b	documents `B3`

data T6

Testing alternative comment styles

Constructors

A4	This is the doc for `A4`
B4	This is the doc for `B4`
C4	This is the doc for `C4`

newtype N1 a

A newtype

Constructors

N1 a

newtype N2 a b

A newtype with a fieldname

Constructors

N2
Fields n :: a b

newtype N3 a b

A newtype with a fieldname, documentation on the field

Constructors

N3
Fields n3 :: a b this is the `n3` field

data N4 a b

An abstract newtype - we show this one as data rather than newtype because the difference isn't visible to the programmer for an abstract type.

newtype N5 a b

Constructors

N5
Fields n5 :: a b no docs on the datatype or the constructor

newtype N6 a b

Constructors

N6	docs on the constructor only
Fields n6 :: a b

newtype N7 a b

docs on the newtype and the constructor

Constructors

N7	The `N7` constructor
Fields n7 :: a b

Records

data R

This is the documentation for the R record, which has four fields, p, q, r, and s.

Constructors

C1	This is the `C1` record constructor, with the following fields:
Fields p :: Int This comment applies to the `p` field q :: forall a. a -> a This comment applies to the `q` field r :: Int This comment applies to both `r` and `s` s :: Int This comment applies to both `r` and `s`
C2	This is the `C2` record constructor, also with some fields:
Fields t :: T1 -> T2 Int Int -> T3 Bool Bool -> T4 Float Float -> T5 () () u :: Int v :: Int

data R1

Testing different record commenting styles

Constructors

C3	This is the `C3` record constructor
Fields s1 :: Int The `s1` record selector s2 :: Int The `s2` record selector s3 :: Int The `s3` record selector

test that we can export record selectors on their own:

Class declarations

class D a => C a where

This comment applies to the previous declaration (the C class)

Methods

a :: IO a

this is a description of the a method

b :: [a]

this is a description of the b method

class D a where

This is a class declaration with no separate docs for the methods

Methods

d :: T a b

e :: (a, a)

Instances

D Float
D Int

class E a

This is a class declaration with no methods (or no methods exported)

Minimal complete definition

ee

class F a where

Methods

ff :: a

Test that we can export a class method on its own:

Function types

f :: C a => a -> Int

In a comment string we can refer to identifiers in scope with single quotes like this: T, and we can refer to modules by using double quotes: Foo. We can add emphasis like this.

This is a bulleted list
This is the next item (different kind of bullet)

This is an ordered list
This is the next item (different kind of bullet)

cat: a small, furry, domesticated mammal
pineapple: a fruit grown in the tropics

     This is a block of code, which can include other markup: R
     formatting
               is
                 significant

this is another block of code

We can also include URLs in documentation: http://www.haskell.org/.

g :: Int -> IO CInt

we can export foreign declarations too

Auxiliary stuff

This is some documentation that is attached to a name ($aux1) rather than a source declaration. The documentation may be referred to in the export list using its name.

 code block in named doc

This is some documentation that is attached to a name ($aux2)

 code block on its own in named doc

 code block on its own in named doc (after newline)

a nested, named doc comment

with a paragraph,

 and a code block

test
test1

 test2
  test3

test1
test2

test3
test4

test1
test2

test3
test4

test3
test4

test1
test2

aux11:

test3
test4

test1
test2

foo

bar

This is some inline documentation in the export list

a code block using bird-tracks
each line must begin with > (which isn't significant unless it
is at the beginning of the line).

A hidden module

hidden :: Int -> Int

A visible module

module Visible

nested-style doc comments

Existential / Universal types

data Ex a

A data-type using existential/universal types

Constructors

forall b . C b => Ex1 b
forall b . Ex2 b
forall b . C a => Ex3 b
Ex4 (forall a. a -> a)

Type signatures with argument docs

k

Arguments

:: T () ()	This argument has type `T`
-> T2 Int Int	This argument has type 'T2 Int Int'
-> (T3 Bool Bool -> T4 Float Float)	This argument has type `T3 Bool Bool -> T4 Float Float`
-> T5 () ()	This argument has a very long description that should hopefully cause some wrapping to happen when it is finally rendered by Haddock in the generated HTML page.
-> IO ()	This is the result type

This is a function with documentation for each argument

l

Arguments

:: (Int, Int, Float)	takes a triple
-> Int	returns an `Int`

m

Arguments

:: R
-> N1 ()	one of the arguments
-> IO Int	and the return value

This function has some arg docs

o

Arguments

:: Float	The input float
-> IO Float	The output float

A foreign import with argument docs

A section

A subsection

a literal line

$ a non literal line $

f' :: Int

a function with a prime can be referred to as f' but f' doesn't get link'd 'f\''

withType :: Int

Comment on a definition with type signature

withoutType :: t

Comment on a definition without type signature