An exercise in combinators using Haskell — In my quest to learn how to use Haskell, I have started tackling the Project Euler suite of problems. I also became enamored with the idea of point-free or tacit programming, a style in which function arguments are implicit, ie. the function argument has no “points” it references. (Note: This…

Implementing Map Square Bracket Indexing for Get/Set in C++ — Disclaimer I like to misuse the word “index” and use it as a verb to mean finding the value at an index in a data structure (often array or list). I further like to misuse this meaning by extending it to “indexing” a map, which is just getting the value stored…

Using closures to build objects using the functional programming paradigm Closures A closure is a functional pattern which results from a different set of variable scoping rules. In C and many other languages, a variable is only valid in the block of code it is defined in. Because the variable…

More infinite lists in scheme This is a continuation of my previous story that can be found here. Stream Combine Last time we made a few interesting streams using stream-add. I want to now introduce a more versatile function that will let us create some more interesting streams. This function is…

Using scheme and lazy evaluation to form infinite lists Tools I will be using the Racket programming language in this guide. It is a much-expanded dialect of scheme, but most of this code should be directly transferable to R5RS-R7RS scheme. I believe concepts can be useful and implemented outside of scheme…

Use of Call/CC in Scheme to “return” early from recursive definitions — What is a Continuation When a function calls another function, it waits for a return value to do something with. For example, in the expression (+ 1 (f x)) ,(+ 1 _)is the continuation for the execution of (f x). …