Miscellaneous predicates

Author(s): Manuel Carro, Daniel Cabeza.

This module implements some miscellaneous non-logical (but sometimes very useful) predicates.

Usage and interface

Library usage:
:- use_module(library(odd)).
Exports:
- Predicates:
  setarg/3, undo/1.

Documentation on exports

Usage:setarg(Index,Term,NewArg)

Replace destructively argument Index in Term by NewArg. The assignment is undone on backtracking. This is a major change to the normal behavior of data assignment in Ciao Prolog.

The following properties should hold at call time:
(term_typing:integer/1)Index is currently instantiated to an integer.
(basic_props:struct/1)Term is a compound term.
(basic_props:term/1)NewArg is any term.

PREDICATEundo/1

Usage:undo(Goal)

call(Goal) is executed on backtracking. This is a major change to the normal control of Ciao Prolog execution.

The following properties should hold at call time:
(basic_props:cgoal/1)Goal is a term which represents a goal, i.e., an atom or a structure.
The following properties should hold upon exit:
(basic_props:cgoal/1)Goal is a term which represents a goal, i.e., an atom or a structure.

Meta-predicate with arguments: undo(goal).

Documentation on imports

This module has the following direct dependencies:

Packages:
prelude, initial, condcomp, assertions, assertions/assertions_basic, isomodes.