letrec-syntax -- r7rs Definition
§

Kind
§

syntax;

Implemented by
§

Syntax signature
§

Syntax keywords:

Syntax variants:

Exports
§

Exports recursive
§

Description
§

(letrec-syntax <bindings> <body>)

Syntax: Same as for let-syntax.

Semantics: The <body> is expanded in the syntactic environment obtained by extending the syntactic environment of the letrec-syntax expression with macros whose keywords are the <keyword>s, bound to the specified transformers. Each binding of a <keyword> has the <transformer-spec>s as well as the <body> within its region, so the transformers can transcribe expressions into uses of the macros introduced by the letrec-syntax expression.

(letrec-syntax
    ((my-or (syntax-rules ()
              ((my-or) #f)
              ((my-or e) e)
              ((my-or e1 e2 ...)
               (let ((temp e1))
                 (if temp
                     temp
                     (my-or e2 ...)))))))
  (let ((x #f)
        (y 7)
        (temp 8)
        (let odd?)
        (if even?))
    (my-or x
           (let temp)
           (if y)
           y)))        ===>  7

The text herein was sourced and adapted as described in the "R7RS attribution of various text snippets" appendix.

Goto: library, categories, exports, definitions, types, appendices, other libraries.