term_string(?Term, ?String)

?Term

Prolog term.

?String

String or a variable.

Description

To change the way the term is converted into a string, e.g. to include print metaterm handlers, it is possible to define it as follows:

term_to_string(T, S) :-
    open(string(""), write, Stream),
    % use the flags which you want
    printf(Stream, "%mw", [T]),
    get_stream_info(Stream, name, S),
    close(Stream).

Fail Conditions

Resatisfiable

Exceptions

(5) type error

String is instantiated, but not to a string.

(7) string contains unexpected characters

String cannot be converted to a Prolog term.

Examples

Success:
      term_string(T, "look").      (gives T=look).
      term_string(T, "26.0").      (gives T=26.0).
      term_string(T, "f(1,2).").   (gives T=f(1,2)).
      term_string(T, "f(1,2)").    (gives T=f(1,2)).
      term_string(f(1,2),L).       (gives L="f(1, 2)").
      term_string(f(1,2),"f(1, 2)").
      term_string(atom,S).         (gives S="atom").
      term_string(.(a,.(1,[])),S). (gives S="[a, 1]").
      term_string(2.60,"2.6").
      term_string(2.6,"2.60").
      term_string(T,S).            (gives T=_g94; S="_g94").

Fail: term_string(2.6,"2.5").

Error:
      term_string(T,atom).              (Error 5).
      [eclipse]: term_string(T,"F(1,2)").  % String not a string
      F(1,2)                               % of a prolog term
       ^ (here?)
      syntax error: unexpected token
      string contains unexpected characters in term_string(T, "F(1,2)")

See Also