1.143.2 Send methods

sheet ->append: attribute

Append an attribute. If the sheet already has an attribute with the same name, the value of the existing attribute is replaced by the value of the argument attribute. See also sheet->value.

Note that attribute<-convert convert an attribute name into an attribute object with value @nil.

See also

sheet->value

sheet ->catch_all: key=name, value=any

The methods sheet<->catch_all are called by PCE's message-passing system if there is no other definition for a method. Class sheet uses these methods to store and fetch attributes:

?- new(@s, sheet(name, age, address)),
   send(@s, name, gnu).

?- get(@s, name, X).

   X = gnu

This approach has, besides its definite charm, one drawbacks: Attributes whose name collide with a method name cannot be accessed this way. Code that handles unknown attribute names should use sheet<->value to avoid this problem.

sheet ->delete: name=any

Delete attribute with the given name. Fails silently if no such attribute exists.

sheet ->for_some: action=code

Run code on all attributes.

sheet ->for_all: action=code

Run code on all sheet<-members. Arguments:

@arg1	attribute object

sheet ->initialise: member=attribute ...

Create a sheet from a list of attributes:

?- new(Sheet, sheet(attribute(name, gnu),
                                        attribute(age, 100))).

sheet ->value: key=any, value=any

Associate name with object. If the sheet already has an attribute with this name, the value of the attribute is changed. Otherwise a new attribute with the given name and value is appended to the sheet.

See also

- sheet->send_catch_all
- sheet->append