Syntax:

with-unique-names (name*) form* => result*

Arguments and Values:

name---a variable to be renamed.

forms---an implicit progn.

results---the values of the forms.

Description:

With-unique-names executes forms in a context in which each name is bound to a similarly named uninterned symbol.

Example:

 (defmacro lister (p q)
    (with-unique-names (x y)
       `(let ((,x (x-function))
              (,y (y-function)))
           (list ,p ,q ,x ,y))))
 => LISTER
 (macroexpand '(lister i j))
 => (LET ((#1=#:X (X-FUNCTION))
          (#2=#:Y (Y-FUNCTION)))
       (LIST I J #1# #2#))
 ;; The actual uninterned symbol names may vary with different
 ;; implementations.  For example, symbols produced by gensym
 ;; might be used.

May increment *GENSYM-COUNTER*.

Affected By:

Symbol names be be effected by *GENSYM-COUNTER*.

Exceptional Situations: None.

See Also:

rebinding, gensym.

Notes:

With-unique-names is intended to facilitate the creation of hygienic macros, in which temporary variable bindings created within a macro use unique names so that there is no danger of unwanted variable capture.

With-unique-names is compatible with similarly named facilities in other Lisp implementations.