Test

Portability	portable
Stability	provisional
Maintainer	libraries@haskell.org

Contents

Type declarations

Data types
Records

Class declarations

Existential / Universal types

Type signatures with argument docs

A section

A subsection

Description

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

Synopsis

data T a b

= A Int (Maybe Float)

| B (T a b, T Int Float)

data T2 a b

data T3 a b

= A1 a

| B1 b

data T4 a b

= A2 a

| B2 b

data T5 a b

= A3 a

| B3 b

data T6

= A4

| B4

| C4

newtype N1 a = N1 a

newtype N2 a b = N2 {

n :: a b

}

newtype N3 a b = N3 {

n3 :: a b

}

data N4 a b

newtype N5 a b = N5 {

n5 :: a b

}

newtype N6 a b = N6 {

n6 :: a b

}

newtype N7 a b = N7 {

n7 :: a b

}

data R

= C1 {

p :: Int

q :: forall a. a -> a

r :: Int

s :: Int

}

| C2 {

t :: T1 -> (T2 Int Int) -> (T3 Bool Bool) -> (T4 Float Float) -> T5 () ()

u :: Int

v :: Int

}

data R1 = C3 {

s1 :: Int

s2 :: Int

s3 :: Int

}

p :: R -> Int

q :: R -> forall a. a -> a

u :: R -> Int

class D a => C a where

a :: IO a

b :: [a]

class D a where

d :: T a b

e :: (a, a)

class E a

class F a where

ff :: a

a :: C a => IO a

f :: C a => a -> Int

g :: Int -> IO CInt

hidden :: Int -> Int

module Visible

data Ex a

= forall b . C b => Ex1 b

| forall b . Ex2 b

| forall b . C a => Ex3 b

| Ex4 (forall a. a -> a)

k :: T () () -> T2 Int Int -> T3 Bool Bool -> T4 Float Float -> T5 () () -> IO ()

l :: (Int, Int, Float) -> Int

m :: R -> N1 () -> IO Int

o :: Float -> IO Float

f' :: Int

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

n :: a b

newtype N3 a b

A newtype with a fieldname, documentation on the field

Constructors

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 :: a b

no docs on the datatype or the constructor

newtype N6 a b

Constructors

docs on the constructor only

n6 :: a b

newtype N7 a b

docs on the newtype and the constructor

Constructors

N7 The N7 constructor

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:

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:

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

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:

p :: R -> Int

This comment applies to the p field

q :: R -> forall a. a -> a

This comment applies to the q field

u :: R -> Int

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)

class F a where

Methods

ff :: a

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

a :: C a => IO a

this is a description of the a method

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

2. This is the next item (different kind of bullet)

     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

:: 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

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

:: R
-> N1 ()	one of the arguments
-> IO Int	and the return value
This function has some arg docs

:: 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\''

Produced by Haddock version 2.1.0