diff --git a/collects/scribblings/htdp-langs/beginner.scrbl b/collects/scribblings/htdp-langs/beginner.scrbl index 415388abeb..180cdcc06f 100644 --- a/collects/scribblings/htdp-langs/beginner.scrbl +++ b/collects/scribblings/htdp-langs/beginner.scrbl @@ -110,6 +110,24 @@ extraction, and type-like queries: The created names must not be the same as a primitive or another defined name.} +@; ---------------------------------------------------------------------- + +@section{@scheme[define-wish]} + +@defform[(define-wish id)]{ + +Defines a function, named id, that we wish exists but have not implemented yet. +The name of the function cannot be that of a primitive or another definition. +The wished for function can be called with one value @scheme[(id expr)]. } + +@defform[(define-wish id expr)] { +Similar to the above form, this defines a wished for function named id. If the +wished for function is called with on value, the result of @scheme[expr] is +returned as the default value. } + +Wished for functions are reported in the test report for the current program. + + @; ---------------------------------------------------------------------- @section[#:tag "beginner-call"]{Function Calls}