[ Strings and Atoms | The ECLiPSe Built-In Predicates | Reference Manual | Alphabetic Index ]

concat_strings(+Src1, +Src2, ?Dest)

Succeeds if Dest is the concatenation of Src1 and Src2.
+Src1
String.
+Src2
String.
?Dest
String or variable.

Description

Dest is unified with the concatenation of Src1 and Src2.

Fail Conditions

Fails if Dest does not unify with the concatenation of Src1 and Src2.

Resatisfiable

No.

Exceptions

(4) instantiation fault
Either (or both) of Src1 and Src2 is not instantiated (non-coroutine mode only).
(5) type error
Either (or both) of Src1 and Src2 is instantiated, but not to a string.
(5) type error
Dest is neither a string nor a variable.

Examples

Success:
  concat_strings("abc","def",X). (gives X="abcdef").

  [eclipse]: [user].
   absolutename(File,Abs) :-
           string_list(File,List),
           arg(1,List,0'/) -> Abs = File;
                            (getcwd(Cwd),
                             concat_strings(Cwd,File,Abs)).
   user compiled 256 bytes in 0.02 seconds
  yes.
  [eclipse]: absolutename("d.pl",P), absolutename("/usr/bin",F).
  P = "/home/lp/user/d.pl"
  F = "/usr/bin"
  yes.

Fail:
  concat_strings("ab","bc","abc").

Error:
  concat_strings("a",X,"ab").             (Error 4).
  concat_strings("big",'gest',X).         (Error 5).

See Also

append_strings / 3, concat_atoms / 3