= Spec-param entity =

Spec-param entities correspond to parameters of a ''-spec'' attribute. Typically these only contain type expressions related to the expected types of parameters in the referenced function's applications, however names can also be specified for parameters in a ''-spec'' attribute. Please note that "-spec" definitions can have multiple clauses, and the index property refers to the parameter's index in the containing clause, so there will be multiple spec-param entities with the same index for any such spec-entity. 

== Selectors ==

''The type of the result elements are indicated in parenthesis.''

* {{{type}}} (''type''): The type expression of the spec-parameter.

== Properties ==

The following properties are defined for spec-param entities:

* {{{name}}} (''atom''): Name of the spec-parameter.
* {{{index}}} (''int''): Index of the spec-parameter in the corresponding clause.
* {{{text}}} (''string''): String representation of the spec-parameter.

== Textual output format ==

When using any of our interfaces, other than [ScriptableInterface ris], this entity will be represented in the output as a string with the same format as it was described in the ''-spec'' form. (Including whitespaces.)

{{{
ri:q("mods.spec.params").
-spec io:format(Format :: string(), list()) -> string().
    Format :: string()
     list()
}}}

== Review of non-trivial selectors ==
For some of the selectors it may not be initially clear how and what would they return. A description of these can be found here: 

=== Specparam.type: ===
Returns the type or type expression of the given specparam. (Single-atom type expressions are filtered.)
{{{
ri:q("mods.spec").           
a.erl
    -spec io_lib:format(Format :: io:format(), list(term())) -> [char].
...
ok
ri:q("mods.spec.param.type").
Format :: io:format()
    Format :: io:format()
 list(term())
    erlang:list/1
...
}}}

=== Specparam.name: ===
Returns the name of the specparam as a string. If the name was omitted, returns "undefined".
{{{
ri:q("mods.spec").           
a.erl
    -spec io_lib:format(Format :: io:format(), list(term())) -> [char].
...
ok
ri:q("mods.spec.param.name").
Format :: io:format()
    name = "Format"
 list(term())
    name = "undefined"
...
}}}