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Diffstat (limited to 'system/doc/reference_manual/modules.xml')
| -rw-r--r-- | system/doc/reference_manual/modules.xml | 45 |
1 files changed, 29 insertions, 16 deletions
diff --git a/system/doc/reference_manual/modules.xml b/system/doc/reference_manual/modules.xml index 9e5f4de385..5fc8b363f8 100644 --- a/system/doc/reference_manual/modules.xml +++ b/system/doc/reference_manual/modules.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2003</year><year>2013</year> + <year>2003</year><year>2014</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -53,10 +53,10 @@ fact(0) -> % | <pre> -Tag(Value).</pre> <p><c>Tag</c> must be an atom, while <c>Value</c> must be a literal - term. As a convenience in user-defined attributes, the literal term - <c>Value</c> the syntax <c>Name/Arity</c> - (where <c>Name</c> is an atom and <c>Arity</c> a positive integer) - will be translated to <c>{Name,Arity}</c>.</p> + term. As a convenience in user-defined attributes, if the literal term + <c>Value</c> has the syntax <c>Name/Arity</c> + (where <c>Name</c> is an atom and <c>Arity</c> a positive integer), + the term <c>Name/Arity</c> will be translated to <c>{Name,Arity}</c>.</p> <p>Any module attribute can be specified. The attributes are stored in the compiled code and can be retrieved by calling @@ -134,8 +134,21 @@ fact(0) -> % | standard behaviours <c>gen_server</c>, <c>gen_fsm</c>, <c>gen_event</c> or <c>supervisor</c>.</p> <p>The spelling <c>behavior</c> is also accepted.</p> - <p>Read more about behaviours and callback modules in OTP Design - Principles.</p> + <p>The callback functions of the module can be specified either + directly by the exported function <c>behaviour_info/1</c>:</p> + <pre> +behaviour_info(callbacks) -> Callbacks.</pre> + <p>or by a <c>-callback</c> attribute for each callback + function:</p> + <pre> +-callback Name(Arguments) -> Result.</pre> + <p>where <c>Arguments</c> is a list of zero or more arguments. + The <c>-callback</c> attribute is to be preferred since the + extra type information can be used by tools to produce + documentation or find discrepancies.</p> + <p>Read more about behaviours and callback modules in + <seealso marker="doc/design_principles:spec_proc#behaviours"> + OTP Design Principles</seealso>.</p> </section> <section> @@ -216,13 +229,9 @@ fact(0) -> % | <p>The <c>module_info/0</c> function in each module returns a list of <c>{Key,Value}</c> tuples with information about the module. Currently, the list contain tuples with the following - <c>Key</c>s: <c>attributes</c>, <c>compile</c>, - <c>exports</c>, and <c>imports</c>. The order and number of tuples + <c>Key</c>s: <c>module</c>, <c>attributes</c>, <c>compile</c>, + <c>exports</c> and <c>md5</c>. The order and number of tuples may change without prior notice.</p> - - <warning><p>The <c>{imports,Value}</c> tuple may be removed in a future - release because <c>Value</c> is always an empty list. - Do not write code that depends on it being present.</p></warning> </section> <section> @@ -233,6 +242,11 @@ fact(0) -> % | <p>The following values are allowed for <c>Key</c>:</p> <taglist> + <tag><c>module</c></tag> + <item> + <p>Return an atom representing the module name.</p> + </item> + <tag><c>attributes</c></tag> <item> <p>Return a list of <c>{AttributeName,ValueList}</c> tuples, @@ -254,10 +268,9 @@ fact(0) -> % | <seealso marker="stdlib:beam_lib#strip/1">beam_lib(3)</seealso>.</p> </item> - <tag><c>imports</c></tag> + <tag><c>md5</c></tag> <item> - <p>Always return an empty list. The <c>imports</c> key may not - be supported in future release.</p> + <p>Return a binary representing the MD5 checksum of the module.</p> </item> <tag><c>exports</c></tag> |