8.1 Attributed variables
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  • Documentation
    • Reference manual
      • Constraint Logic Programming
        • Attributed variables
          • Attribute manipulation predicates
          • Attributed variable hooks
          • Operations on terms with attributed variables
          • Special purpose predicates for attributes
            • get_attrs/2
            • put_attrs/2
            • del_attrs/1
    • Packages

8.1.4 Special purpose predicates for attributes

Normal user code should deal with put_attr/3, get_attr/3 and del_attr/2. The routines in this section fetch or set the entire attribute list of a variable. Use of these predicates is anticipated to be restricted to printing and other special purpose operations.

get_attrs(+Var, -Attributes)
Get all attributes of Var. Attributes is a term of the form att(Module, Value, MoreAttributes), where MoreAttributes is [] for the last attribute.
put_attrs(+Var, -Attributes)
Set all attributes of Var. See get_attrs/2 for a description of Attributes.
del_attrs(+Var)
If Var is an attributed variable, delete all its attributes. In all other cases, this predicate succeeds without side-effects.