diff options
Diffstat (limited to 'doc/markup.rst')
| -rw-r--r-- | doc/markup.rst | 51 |
1 files changed, 47 insertions, 4 deletions
diff --git a/doc/markup.rst b/doc/markup.rst index 4e00f708..56238855 100644 --- a/doc/markup.rst +++ b/doc/markup.rst @@ -8,6 +8,8 @@ will just generate documentation that contains the type signatures, data type declarations, and class declarations exported by each of the modules being processed. +.. _top-level-declaration + Documenting a Top-Level Declaration ----------------------------------- @@ -47,6 +49,8 @@ the following: - A ``class`` declaration, +- An ``instance`` declaration, + - A ``data family`` or ``type family`` declaration, or - A ``data instance`` or ``type instance`` declaration. @@ -106,6 +110,8 @@ signatures, by using either the ``-- |`` or ``-- ^`` annotations: :: -- | This is the documentation for the 'g' method g :: Int -> a +Associated type and data families can also be annotated in this way. + Constructors and Record Fields ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -166,6 +172,32 @@ would join up documentation of each field and render the result. The reason for this seemingly weird behaviour is the fact that ``someField`` is actually the same (partial) function. +Deriving clauses +~~~~~~~~~~~~~~~~ + +Most instances are top-level, so can be documented as in +:ref:`top-level-declaration`. The exception to this is instance that are +come from a ``deriving`` clause on a datatype declaration. These can +the documented like this: :: + + data D a = L a | M + deriving ( Eq -- ^ @since 4.5 + , Ord -- ^ default 'Ord' instance + ) + +This also scales to the various GHC extensions for deriving: :: + + newtype T a = T a + deriving Show -- ^ derivation of 'Show' + deriving stock ( Eq -- ^ stock derivation of 'Eq' + , Foldable -- ^ stock derivation of 'Foldable' + ) + deriving newtype Ord -- ^ newtype derivation of 'Ord' + deriving anyclass Read -- ^ unsafe derivation of 'Read' + deriving ( Eq1 -- ^ deriving 'Eq1' via 'Identity' + , Ord1 -- ^ deriving 'Ord1' via 'Identity' + ) via Identity + Function Arguments ~~~~~~~~~~~~~~~~~~ @@ -175,8 +207,8 @@ Individual arguments to a function may be documented like this: :: -> Float -- ^ The 'Float' argument -> IO () -- ^ The return value -Pattern synonyms and GADT-style data constructors also support this -style of documentation. +Pattern synonyms, GADT-style data constructors, and class methods also +support this style of documentation. .. _module-description: @@ -881,6 +913,16 @@ If ``M.T`` is not otherwise in scope, then Haddock will simply emit a link pointing to the entity ``T`` exported from module ``M`` (without checking to see whether either ``M`` or ``M.T`` exist). +Since values and types live in different namespaces in Haskell, it is +possible for a reference such as ``'X'`` to be ambiguous. In such a case, +Haddock defaults to pointing to the type. The ambiguity can be overcome by explicitly specifying a namespace, by way of a ``v`` (for value) or ``t`` +(for type) immediately before the link: :: + + -- | An implicit reference to 'X', the type constructor + -- An explicit reference to v'X', the data constructor + -- An explicit reference to t'X', the type constructor + data X = X + To make life easier for documentation writers, a quoted identifier is only interpreted as such if the quotes surround a lexically valid Haskell identifier. This means, for example, that it normally isn't @@ -890,8 +932,9 @@ necessary to escape the single quote when used as an apostrophe: :: Nothing special is needed to hyperlink identifiers which contain apostrophes themselves: to hyperlink ``foo'`` one would simply type -``'foo''``. To hyperlink identifiers written in infix form, simply put -them in quotes as always: ``'`elem`'``. +``'foo''``. Hyperlinking operators works in exactly the same way. :: + + -- | A prefix operator @'(++)'@ and an infix identifier @'`elem`'@. Emphasis, Bold and Monospaced Text ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |