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type_of(?Term, -Type)

Succeeds if Type is the data type of the term Term.
Term
Prolog term.
Type
Atom or variable.

Description

The type of the term Term is unified with Type.

The types are atoms from the set: string, atom, var, integer, rational, float, breal, compound, handle, db_reference, goal.

Modes and Determinism

Exceptions

(5) type error
Type is instantiated, but not to an atom.

Examples

Success:
      type_of(X,T).         (gives T=var).
      type_of([1,2],T).     (gives T=compound).
      type_of([],atom).
      type_of(#,atom).
      type_of($,atom).
      type_of(*,atom).
      type_of(/,atom).
      type_of(\,atom).
      type_of("a",string).
      type_of(1,integer).
      type_of(123456789012345,integer).
      type_of(1_3,rational).
      type_of(1.0,float).
      type_of(0.99__1.01,breal).
      type_of(a(b),compound).
      record(k, a), recorded(k, _, R), type_of(R, db_reference).
      make_suspension(true,3,S), type_of(S, goal).
Fail:
      type_of(2.0,integer).
      type_of(2.0,float).
Error:
      type_of(2,"atom").  (Error 5).



See Also

atom / 1, callable / 1, compound / 1, free / 1, integer / 1, meta / 1, number / 1, nonground / 1, breal / 1, rational / 1, float / 1, float / 1, real / 1, string / 1, var / 1