concat

[This is preliminary specification and subject to change.]

Group

Prolog predicates (more...)

Type

determ

Syntax

concat( STRING A, STRING B, STRING C)

Flow patterns

(i,i,o),(o,i,i),(i,o,i),(i,i,i)

Description:

The concat works as if defined by the equation:
LongString = String1 + String2

Sample:

predicates
    determ prolog_main
clauses
prolog_main:-
    concat("aaa","bbb",X), /*(i,i,o)*/
    write("X=",X),nl,
    fail.
prolog_main:-
    concat("aaa",X,"aaa----bbb"), /*(i,o,i)*/
    write("X=",X),nl,
    fail.
prolog_main:-
    concat(X,"bbb","aaa----bbb"), /*(o,i,i)*/
    write("X=",X),nl,
    fail.
prolog_main:-
    A = "aaa", B = "bbb", C = "aaabbb",
    concat(A,B,C),  /*(i,i,i)*/
    write("Correct - A =",A,", B=",B,", C=",C),nl,
    fail.
prolog_main:-
    A = "aaa", B = "bbb", C = "aaa----bbb",
    not( concat(A,B,C)),  /*(i,i,i)*/
    write("Incorrect - A =",A,", B=",B,", C=",C),nl,
    fail.
prolog_main:-
    write("Hello World from EZY Prolog"),nl,!.
goal
    prolog_main.