From b63cb42acf024610d555e25d0e3130c34804f350 Mon Sep 17 00:00:00 2001 From: Matthias Felleisen Date: Fri, 3 Feb 2012 10:29:45 -0500 Subject: [PATCH] fixed documentation for check-within --- collects/scribblings/htdp-langs/prim-ops.rkt | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/collects/scribblings/htdp-langs/prim-ops.rkt b/collects/scribblings/htdp-langs/prim-ops.rkt index 30288e3b58..3795480029 100644 --- a/collects/scribblings/htdp-langs/prim-ops.rkt +++ b/collects/scribblings/htdp-langs/prim-ops.rkt @@ -309,12 +309,18 @@ @defform*[#:id [check-within check-within-id] - [(check-within expression expected-expression delta-expression)]]{ + [(check-within expression expected-expression delta)]]{ - Checks that the first @racket[expression] evaluates to a value within - @racket[delta-expression] of the @racket[expected-expression]. If - @racket[delta-expression] is not a number, @check-within-elem reports an - error.} + Checks whether the value of the @racket[expression] expression is + structurally equal to the value produced by the + @racket[expected-expression] expression; every number in the first + expression must be within @racket[delta] of the corresponding number in + the second expression. + + It is an error for @racket[expressions] or @racket[expected-expression] + to produce a function value. + + If @racket[delta] is not a number, @check-within-elem reports an error.} @defform*[#:id [check-error check-error-id]