diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/haddock.sgml | 178 |
1 files changed, 149 insertions, 29 deletions
diff --git a/doc/haddock.sgml b/doc/haddock.sgml index 959e396a..2564a14b 100644 --- a/doc/haddock.sgml +++ b/doc/haddock.sgml @@ -421,6 +421,30 @@ square x = x * x then Haddock can't tell what its type is and it won't be included in the documentation.</para> + <para>Documentation annotations may span several lines; the + annotation continues until the first non-comment line in the + source file. For example:</para> + +<programlisting> +-- |The 'square' function squares an integer. +-- It takes one argument, of type 'Int'. +square :: Int -> Int +square x = x * x +</programlisting> + + <para>You can also use Haskell's nested-comment style for + documentation annotations, which is sometimes more convenient + when using multi-line comments:</para> + +<programlisting> +{-| + The 'square' function squares an integer. + It takes one argument, of type 'Int'. +-} +square :: Int -> Int +square x = x * x +</programlisting> + </section> <section> <title>Documenting parts of a declaration</title> @@ -591,18 +615,45 @@ module Foo ( list:</para> <programlisting> -module Foo ( - module Bar, - module Baz +module A ( + module B, + module C ) where </programlisting> <para>What will the Haddock-generated documentation for this - module look like? Well, Haddock simply behaves as if the - export list for modules <literal>Bar</literal> and - <literal>Baz</literal> had been expanded in-place in the - export list for <literal>Foo</literal>, including all of their - structure (section headings etc.).</para> + module look like? Well, it depends on how the modules + <literal>B</literal> and <literal>C</literal> are imported. + If they are imported wholly and without any + <literal>hiding</literal> qualifiers, then the documentation + will just contain a cross-reference to the documentation for + <literal>B</literal> and <literal>C</literal>. However, if + the modules are not <emphasis>completely</emphasis> + re-exported, for example:</para> + +<programlisting> +module A ( + module B, + module C + ) where + +import B hiding (f) +import C (a, b) +</programlisting> + + <para>then Haddock behaves as if the set of entities + re-exported from <literal>B</literal> and <literal>C</literal> + had been listed explicitly in the export + list<footnote><para>NOTE: this is not fully implemented at the + time of writing (version 0.2). At the moment, Haddock always + inserts a cross-reference.</para> + </footnote>.</para> + + <para>The exception to this rule is when the re-exported + module is declared with the <literal>hide</literal> attribute + (<xref linkend="module-attributes">), in which case the module + is never cross-referenced; the contents are always expanded in + place in the re-exporting module.</para> </section> <section> @@ -639,6 +690,7 @@ module Foo ( <programlisting> module Foo ( -- * A section heading + -- | Some documentation not attached to a particular Haskell entity ... ) where @@ -656,6 +708,7 @@ module Foo ( <programlisting> module Foo ( -- * A section heading + -- $doc ... ) where @@ -742,6 +795,61 @@ import B </itemizedlist> </section> + <section id="module-attributes"> + <title>Module Attributes</title> + + <para>Certain attributes may be specified for each module which + affects the way that Haddock generates documentation for that + module. Attributes are specified in a comma-separated list in a + <literal>-- #</literal> (or + <literal>{- # ... -}</literal>) comment at the + top of the module, either before or after the module + description. For example:</para> + +<programlisting> +-- #hide, prune, ignore-exports +-- |Module description +module A where +... +</programlisting> + + <para>The following attributes are currently understood by + Haddock:</para> + + <variablelist> + <varlistentry> + <term><literal>hide</literal></term> + <indexterm><primary><literal>hide</literal></primary></indexterm> + <listitem> + <para>Omit this module from the generated documentation, + but nevertheless propagate definitions and documentation + from within this module to modules that re-export those + definitions.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>prune</literal></term> + <indexterm><primary><literal>hide</literal></primary></indexterm> + <listitem> + <para>Omit definitions that have no documentation + annotations from the generated documentation.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>ignore-exports</literal></term> + <indexterm><primary><literal>hide</literal></primary></indexterm> + <listitem> + <para>Ignore the export list. Generate documentation as + if the module had no export list - i.e. all the top-level + declarations are exported, and section headings may be + given in the body of the module.</para> + </listitem> + </varlistentry> + </variablelist> + </section> + <section> <title>Markup</title> @@ -764,42 +872,34 @@ import B <para>The following characters have special meanings in documentation comments: <literal>/</literal>, - <literal>'</literal>, <literal>[</literal>, - <literal>]</literal>, <literal><</literal>. To insert a - literal occurrence of one of these special characters, precede - it with a backslash (<literal>\</literal>).</para> - - <para>Additionally, the following characters have special - meanings at the beginning of a paragraph: + <literal>'</literal>, <literal>`</literal>, + <literal>"</literal>, <literal>@</literal>, + <literal><</literal>. To insert a literal occurrence of + one of these special characters, precede it with a backslash + (<literal>\</literal>).</para> + + <para>Additionally, the character <literal>></literal> has + a special meaning at the beginning of a line, and the + following characters have special meanings at the beginning of + a paragraph: <literal>*</literal>, <literal>-</literal>. These characters can also be escaped using <literal>\</literal>.</para> - - </section> - - <section> - <title>Emphasis and Monospaced text</title> - - <para>Emphasis may be added by surrounding text with - <literal>/.../</literal>.</para> - - <para>Monospaced (or typewriter) text is indicated by - surrounding it with <literal>[...]</literal>.</para> </section> <section> <title>Code Blocks</title> <para>Displayed blocks of code are indicated by surrounding a - paragraph with <literal>[...]</literal> or by preceding each + paragraph with <literal>@...@</literal> or by preceding each line of a paragraph with <literal>></literal>. For example:</para> <programlisting> -- | This documentation includes two blocks of code: -- --- [ +-- @ -- f x = x + x --- ] +-- @ -- -- > g x = x * 42 </programlisting> @@ -822,6 +922,26 @@ import B <literal>T</literal> (if the output format supports hyperlinking, of course; in a printed format it might instead insert a page reference to the definition).</para> + + <para>For compatibility with other systems, the following + alternative form of markup is accepted<footnote><para> + We chose not to use this as the primary markup for + identifiers because strictly speaking the <literal>`</literal> + character should not be used as a left quote, it is a grave accent.</para> + </footnote>: <literal>`T'</literal>.</para> + </section> + + <section> + <title>Emphasis and Monospaced text</title> + + <para>Emphasis may be added by surrounding text with + <literal>/.../</literal>.</para> + + <para>Monospaced (or typewriter) text is indicated by + surrounding it with <literal>@...@</literal>. Other markup is + valid inside a monospaced span: for example + <literal>@'f' a b@</literal> will hyperlink the + identifier <literal>f</literal> inside the code fragment.</para> </section> <section> |