If Scheme is untyped, how can it have numbers and lists?
Scheme is said to be just an extension of the Untyped Lambda Calculus (correct me if I am wrong). If that is the case, how can it have Lists and Numbers? Those, to me, look like 2 base types. So I’d say Racket is actually an extension of the Simply Typed Lambda Calculus. No?
Abstract List Functions in Racket/Scheme
I’m completely stuck on a problem to write a function that does NOT use recursion, locals, or lambda. Only abstract list functions can be used.
The function must input a list of positive integers, and output a list of integers that are strictly greater than 1.
Two dimensional matrix-like data type using lists and/or mutable lists
I am trying to think of an implementation of a two dimensional matrix-like data type.
Normally I would take an array of arrays but I’m bound to a relatively low language level which only provides lists and mutable lists, because this is part of (but not an exercise itself, I could simply use an inefficient solution) a software project at university. In this, we are only allowed to use a specific language level.
So of cause I could take a list of mutable lists and, in search of an item in row n and column m, get the m-th mutable list and go throught it until position n. But isn’t there a better solution than going through the whole list?
in drracket version 8.12 how to trace a function?
my quesion is how can i trace a function in drracket version 8.12?