ac26fe7554
Also, updates some of the mzlib files to point at `racket/*' libraries rather than to `scheme/*' ones.
36 lines
928 B
Racket
36 lines
928 B
Racket
#lang scribble/doc
|
|
@(require "mz.rkt" scribble/eval (for-label racket/block))
|
|
|
|
@(define ev (make-base-eval))
|
|
@(ev '(require racket/block))
|
|
|
|
@title[#:tag "block"]{Blocks: @racket[block]}
|
|
|
|
@note-lib-only[racket/block]
|
|
|
|
@defform[(block defn-or-expr ...)]{
|
|
|
|
Supports a mixture of expressions and mutually recursive definitions,
|
|
as in a @racket[module] body. Unlike an @tech{internal-definition
|
|
context}, the last @racket[defn-or-expr] need not be an expression.
|
|
|
|
The result of the @racket[block] form is the result
|
|
of the last @racket[defn-or-expr] if it is an expression,
|
|
@|void-const| otherwise. If no @racket[defn-or-expr] is provided
|
|
(after flattening @racket[begin] forms), the result is @|void-const|.
|
|
|
|
The final @racket[defn-or-expr] is executed in tail position, if it is
|
|
an expression.
|
|
|
|
|
|
@examples[#:eval ev
|
|
(define (f x)
|
|
(block
|
|
(define y (add1 x))
|
|
(displayln y)
|
|
(define z (* 2 y))
|
|
(+ 3 z)))
|
|
(f 12)
|
|
]}
|
|
|