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concat_atom(+List, ?Dest)

Succeeds if Dest is the concatenation of the atomic terms contained in List. It is more efficient to use concat_string/2 whenever possible.
+List
List of atomic terms.
?Dest
Atom or variable.

Description

Dest is unified with the concatenation of the atomic terms contained in List. List may contain numbers, atoms and strings. The result of the concatenation is always an atom.

The use of this predicate is discouraged in favour of concat_string/2, because the creation of new atoms involves entering them into a dictionary whose garbage collection is relatively expensive.

Fail Conditions

Fails if Dest does not unify with the concatenation of the terms in List.

Resatisfiable

No.

Exceptions

(4) instantiation fault
List is not instantiated (non-coroutine mode only).
(4) instantiation fault
List contains free variables (non-coroutine mode only).
(5) type error
List is instantiated, but not to a list of atomic terms.
(5) type error
Dest is neither an atom nor a variable.

Examples

Success:
      concat_atom([abc,def],abcdef).

      concat_atom(["Str1","Str2"],X).
                             X = 'Str1Str2'.

      concat_atom([the,man," is aged ",20],X).
                             X = 'theman is aged 20'.

      concat_atom([1,2,3],X)
                             X = '123'.

Fail:
      concat_atom([ab,bc],abc).

Error:
      concat_atom(A,X).        (Error 4).
      concat_atom([abc,D],X).  (Error 4).
      concat_atom(art,X).      (Error 5).

See Also

concat_string / 2, concat_atoms / 3, atom_string / 2, join_string / 3