Spec entity

Spec entities correspond to -spec attributes in erlang sources. The specification for a given function is commonly present in the module where the function is defined, but it can also be placed in header files or other modules. A function might have more than one specification even if it consists of only one clause. Please note that in our representation, there is no "1:1" correlation between function clauses and -spec attributes, so any given function clause has all specs of the entire function.

Initial selector

A -spec attribute can be indicated by a given position. In this case the @spec initial-selector returns the spec entity corresponding to the indicated attribute in the source.

Selectors

The type of the result elements are indicated in parenthesis.

• function (function): The function that has this spec.
• file (file): The file in which the spec was defined.
• refmod (file): The file to which the spec pertains. (If a module identifier has been used in the spec, the result may differ from the defining file.)
• returntype (type): Possible return types of the spec.
• guardtype (type): Types of the spec-guards.
• arguments (specparam): Arguments of the spec.

Properties

The following properties are defined for spec entities:

• name (atom): Name of the function spec.
• arity (int): Arity of the spec.
• text (string): String representation of the spec.
• returntext (string): String representation of the spec's return values.
• guardtext (string): String representation of the spec's guards.

Textual output format

When using any of our interfaces, other than ris?, this entity will be represented in the output as a string with the same format as it was defined in the source file.

ri:q("mods.spec").
a.erl
    -spec io_lib:format(Format :: atom() | string() | binary(), D) -> [char] when D :: list(term()).
...

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:

Spec.refmod:

Specs can have module-identifiers which determine the module whose function is being specified. This module is returned by the selector unless the module-identifier was omitted, in which case the defining module is returned.

ri:q("mods.spec.refmod").     
-spec io_lib:format(Format :: atom() | string() | binary(), D) -> [char] when D :: list(term()).
    io_lib
...

Spec.arguments:

Returns the type expression for the arguments of the specification. Argument-names are included.

ri:q("mods.spec.args").  
-spec io_lib:format(Format :: atom() | string() | binary(), D) -> [char] when D :: list(term()).
    Format :: atom() | string() | binary()
     D
...

Spec.guardtypes:

Returns the type expressions of spec-guards.

ri:q("mods.spec.guardtypes").
-spec io_lib:format(Format :: atom() | string() | binary(), D) -> [char] when D :: list(term()).
     D :: list(term())
...