Racket is an extensible general programming language in the Lisp family.

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Extracting values from a list

I had already solved this problem, but in an unnecessarily convoluted way that seems too specific. Can this be done better? From a list: (8 "layer-name" 10 x1 20 y1 10 x2 20 y2 10 x3 20 y3) 8, ...
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Simple evaluator of Scheme-like expressions in Haskell

This is my first nontrivial Haskell program: ...
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Calculating continued fraction expansions (without requiring arbitrary precision decimals)

I'm writing a program that will compute a continued fraction expansion of a number. I've been learning Racket/Scheme for a few weeks and I wanted to see what I can do better. Usage: This program ...
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Finding the subsets of a set

I am trying to write a procedure that finds the power set of a list, that is, the set of 2n subsets (where n is the number of elements in the list). I simply quite find all the subsets. I feel my code ...
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Reading/writing null-terminated strings from socket

I need to handle C style ('\0' delimited) strings from/to a socket and came up with this as a first attempt: ...
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Is this IRC bot utility library Racket-y enough?

To help myself learn Racket, I ported a simple JavaScript ircbot module I wrote for Node.js to Racket. The Racket version is built atop the Racket irc package, so ...
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Solving the N-queens puzzle the Racket or Scheme way

My final version is a direct translation from Python. Thanks to build-in support for generator, its speed is almost the same as Python. As I quite like using generator and list comprehension in ...
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Is there a better way to document this or is this good enough?

I finished answering Exercise 3.3.1 of How to Design Programs where: Exercise 3.3.1. The United States uses the English system of (length) measurements. The rest of the world uses the metric ...
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Tridiagonal Lists in Scheme

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Project Euler 1 (sum of multiples of 3 or 5 under 1000)

I solved this a while ago. In the moment I solved it I was learning Scheme and, well, I still am. I'm not looking at the best solution (I searched for it and coded it already, in Python), what I want ...
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117 views

Simplifying Dr.Racket drawing code

I am using Dr.Racket, Intermediate Student with Lambda. I was wondering if there was any way I can simplify this code using any sort of method like lambda, abstraction, map, filter, etc. ...
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Simplifying Dr.Racket alien code

I am using Dr.Racket, Intermediate Student with Lambda. I was wondering if there was any way I can simplify this code using any sort of method like lambda, abstraction, map, filter, etc. ...
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2answers
248 views

Why is this RC4 code in Racket so slow?

According to shootout.alioth.debian.org, Racket is not much slower than C#, at least in the same order of magnitude due to its JIT compiler. However, I'm seeing at least two degrees of magnitude ...
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Creating an updating hash table

I'm not sure if this implementation is good enough. The function takes a vector of 1 million chars and creates a table of the sequences that pass before the next occurrence of itself. Some questions ...
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Quick Insert Merge Sort

I have written this code to sort a list of numbers, in increasing order. It is a combination of quick sort, insertion sort, and merge sort. I make the first element of the list a pivot, then I go ...
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1answer
306 views

Scheme/Racket: idiomatic infix math evaluator

Inspired by xkcd and a couple of praising blog posts, I decided to try out Lisp. It seemed that the best-supported dialect was Racket, itself a variant of Scheme, so I went with that and wrote an ...
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375 views

Improving a priority queue sketch in Racket/Scheme

I just put together the skeletons for a priority queue using a binary heap in racket/scheme. Using racket/scheme is all about the educational experience and I was wondering if anyone wants to ...
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224 views

A Simple Unix Filter in Racket - Learning the Racket Way

I've written the following simple filter in Racket as my first Racket program and am wondering if I am writing it in an "idiomatic Racket style". ...
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Insert-everywhere

This is HTDP Excercise 12.4.2 :- Page 161 Develop a function insert-everywhere. It consumes a symbol and a list of words. The result is a list of words like its second argument, but with the ...