src/swipl-devel/packages/xpce/man/refmanual/md/nameref.md

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class nameref {#class-nameref}

The code class @= assigns a global named reference to an object. It is introduced to provide for a better syntax to create global objects from the XPCE Defaults file (notably display.initialise).

@= is defined as an infix operator (xfx, priority 990) by the Defaults value parser. The following example defines a global object:

_window_pen @= number(1)

After this the global object @_window_pen refers to a number object with value 1. See also the XPCE Defaults file, normally located in $PCEHOME/Defaults, where $PCEHOME refers to the XPCE homd directory (see @pce <-home).

The construct

name @= object

is equivalent to

message(object, name_reference, name).

Except that --if the object is a function object-- the function is assigned the reference instead of the object the function evaluates to.

See also object ->name_reference, pce_global/2, class var and class assign.

NOTE: Application programmers should not use this class. it is introduced to allow for parsing the @= construct by the Defaults parser. Later releases of the parser may use an alternative implementation (i.e. some form of active macro-expansion instead of executable objects).

Instance variables {#class-nameref-instvars}

• nameref-object Object or function that should be assigned a reference name on ->execute'ing.

• nameref-reference Reference name given to <-object on ->execute.

Send methods {#class-nameref-send}

• nameref->_execute Invoke send(<-object, name_reference, <-reference). See also object ->name_reference.

• nameref->initialise Simply fills <-reference and <-object from the arguments.

rswipl documentation built on June 16, 2026, 5:07 p.m.