( define* Reference

Info Catalog ( lambda* Reference ( Optional Arguments
 23.2.4 define* Reference
 Just like `define' has a shorthand notation for defining procedures
 ( Lambda Alternatives), `define*' is provided as an abbreviation
 of the combination of `define' and `lambda*'.
    `define*-public' is the `lambda*' version of `define-public';
 `defmacro*' and `defmacro*-public' exist for defining macros with the
 improved argument list handling possibilities.  The `-public' versions
 not only define the procedures/macros, but also export them from the
 current module.
  -- library syntax: define* formals body
  -- library syntax: define*-public formals body
      `define*' and `define*-public' support optional arguments with a
      similar syntax to `lambda*'. They also support arbitrary-depth
      currying, just like Guile's define. Some examples:
           (define* (x y #:optional a (z 3) #:key w . u)
              (display (list y z u)))
      defines a procedure `x' with a fixed argument Y, an optional
      argument A, another optional argument Z with default value 3, a
      keyword argument W, and a rest argument U.
           (define-public* ((foo #:optional bar) #:optional baz) '())
      This illustrates currying. A procedure `foo' is defined, which,
      when called with an optional argument BAR, returns a procedure
      that takes an optional argument BAZ.
      Of course, `define*[-public]' also supports `#:rest' and
      `#:allow-other-keys' in the same way as `lambda*'.
  -- library syntax: defmacro* name formals body
  -- library syntax: defmacro*-public name formals body
      These are just like `defmacro' and `defmacro-public' except that
      they take `lambda*'-style extended parameter lists, where
      `#:optional', `#:key', `#:allow-other-keys' and `#:rest' are
      allowed with the usual semantics. Here is an example of a macro
      with an optional argument:
           (defmacro* transmorgify (a #:optional b)
               (a 1))
Info Catalog ( lambda* Reference ( Optional Arguments
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