Control constructs/predicates

Conjunction (P and Q).

Usage:ISO

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

Disjunction (P or Q). Note that in Ciao |/2 is not equivalent to ;/2.

Usage:ISO

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

If P then Q else fail, using first solution of P only. Also, (P -> Q ; R), if P then Q else R, using first solution of P only. No cuts are allowed in P.

Usage:ISO

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

Usage:ISO

Commit to any choices taken in the current predicate.

• The following properties hold globally:
  (native_props:is_det/1)All calls of the form ! are deterministic.
  (native_props:not_fails/1)All the calls of the form ! do not fail.
  (native_props:relations/2)Goal ! produces 1 solutions.

Goal P is not provable (negation by failure). Fails if P has a solution, and succeeds otherwise. No cuts are allowed in P.

Usage:ISO

• The following properties should hold at call time:
  (basic_props:cgoal/1)P is a term which represents a goal, i.e., an atom or a structure.
• The following properties hold globally:
  (basic_props:native/2)This predicate is understood natively by CiaoPP as not(X).
  (native_props:is_det/1)All calls of the form \+P are deterministic.

If P then Q else R, exploring all solutions of P. No cuts are allowed in P.

Usage:if(A,B,C)

• The following properties should hold at call time:
  (term_typing:nonvar/1)A is currently a term which is not a free variable.
  (term_typing:nonvar/1)B is currently a term which is not a free variable.
  (term_typing:nonvar/1)C is currently a term which is not a free variable.
  (basic_props:cgoal/1)A is a term which represents a goal, i.e., an atom or a structure.
  (basic_props:cgoal/1)B is a term which represents a goal, i.e., an atom or a structure.
  (basic_props:cgoal/1)C is a term which represents a goal, i.e., an atom or a structure.
• The following properties hold upon exit:
  (basic_props:cgoal/1)A is a term which represents a goal, i.e., an atom or a structure.
  (basic_props:cgoal/1)B is a term which represents a goal, i.e., an atom or a structure.
  (basic_props:cgoal/1)C is a term which represents a goal, i.e., an atom or a structure.

Usage:ISO

Succeed (noop).

• The following properties hold globally:
  (basic_props:native/1)This predicate is understood natively by CiaoPP.
  (basic_props:sideff/2)true is side-effect free.
  (native_props:is_det/1)All calls of the form true are deterministic.
  (native_props:not_fails/1)All the calls of the form true do not fail.
  (native_props:relations/2)Goal true produces 1 solutions.

• The following properties hold globally:
  (basic_props:eval/1)true is evaluable at compile-time.

Usage:ISO

Fail, backtrack immediately.

• The following properties hold globally:
  (basic_props:native/1)This predicate is understood natively by CiaoPP.
  (basic_props:sideff/2)fail is side-effect free.
  (native_props:is_det/1)All calls of the form fail are deterministic.
  (basic_props:fails/1)Calls of the form fail fail.
  (native_props:relations/2)Goal fail produces 0 solutions.

• The following properties hold globally:
  (basic_props:eval/1)fail is evaluable at compile-time.

• The following properties hold globally:
  (basic_props:equiv/2)fail is equivalent to fail.

Usage:ISO

Generates an infinite sequence of backtracking choices.

• The following properties hold globally:
  (basic_props:native/1)This predicate is understood natively by CiaoPP.
  (basic_props:sideff/2)repeat is side-effect free.

• The following properties hold globally:
  (basic_props:sideff/2)false is side-effect free.
  (basic_props:eval/1)false is evaluable at compile-time.

• The following properties hold globally:
  (basic_props:sideff/2)otherwise is side-effect free.
  (basic_props:eval/1)otherwise is evaluable at compile-time.