PropertyGet Function R←Get {ipa}

The name of the PropertyGet function must be Get, but is case-independent. For example, get, Get, gEt and GET are all valid names for the PropertyGet function.

The PropertyGet function must be result returning. For a Simple Property, it may be monadic or niladic. For a Numbered or Keyed Property it must be monadic.

The result R may be any array. However, for a Keyed Property, R must conform to the rank and shape specified by ipa.Indexers or be scalar.

If monadic, ipa is an instance of the internal class PropertyArguments.

In all cases, ipa.Name contains the name of the Property being referenced and NewValue is undefined (VALUE ERROR).

If the Property is Simple, ipa.Indexers is undefined (VALUE ERROR).

If the Property is Numbered, ipa.Indexers is an integer vector of the same length as the rank of the property (as implied by the result of the Shape function) that identifies a single element of the Property whose value is to be obtained. In this case, R must be scalar.

If the Property is Keyed, ipa.IndexersSpecified is a Boolean vector with the same length as the rank of the property (as implied by the result of the Shape function). A value of 1 means that an indexing array for the corresponding dimension of the Property was specified, while a value of 0 means that the corresponding dimension was elided. ipa.Indexers is a vector of the same length containing the arrays that were specified within the square brackets in the reference expression. Specifically, ipa.Indexers will contain one fewer elements than, the number of semi-colon (;) separators. If any index was elided, the corresponding element of ipa.Indexers is ⎕NULL.

Note

It is not possible to predict the number of times that a PropertyGet, PropertySet or PropertyShape function will be called by a particular APL expression, as this depends upon how that expression is implemented internally. You should therefore not rely on the number of times that a Get, Set or Shape function is called, and none should have any side effects on any other APL object