format_predicate2+Char, +Head
If a sequence c (tilde, followed by some character) is
found, the format derivatives will first check whether the user has
defined a predicate to handle the format. If not, the built in
formatting rules described above are used. Char is either an ASCII value, or a one character atom, specifying the letter to be
(re)defined. Head is a term, whose name and arity are used to
determine the predicate to call for the redefined formatting character.
The first argument to the predicate is the numeric argument of the
format command, or the atom default if no argument is specified.
The remaining arguments are filled from the argument list. The example
below redefines n to produce Arg times return
followed by linefeed (so a (Grr.) DOS machine is happy with the output).
current_format_predicate2?Code, ?:Head
Enumerates all user-defined format predicates. Code is the
character code of the format character. Head is unified with
a term with the same name and arity as the predicate. If the
predicate does not reside in module user, Head is
qualified with the definition module of the predicate.
