
atom_length(+Atom, -Length)

   Succeeds if Length is the length of Atom.



Arguments
   Atom                Atom.
   Length              Integer or variable.

Type
   Strings and Atoms

Description
   The length of an atom Atom is unified with Length.  The length of an
   atom is the number of characters in the atom's name.


    Note that (like all predicates that return a number as their last
    argument), this predicate can be used as a function inside arithmetic
    expressions.


Modes and Determinism
   atom_length(+, -) is det

Exceptions
     4 --- Atom is not instantiated (non-coroutine mode only).
     5 --- Atom is instantiated, but not to an atom.
     5 --- Length is neither an integer nor a variable.

Examples
   
Success:
      atom_length(test, 4).
      atom_length(test,L).         (gives L = 4).
      atom_length(as, X).          (gives X = 2).
      atom_length('4', 1).

Fail:
      atom_length(test, 5).

Error:
      atom_length(Atom, 2).        (Error 4).
      atom_length(Atom, 2.0).      (Error 5).
      atom_length(4, 1).           (Error 5).
      atom_length(as, 2.0).        (Error 5).





See Also
   atom / 1, atom_string / 2, string_length / 2
