Questions tagged [lisp]
Lisp is a (family of) general purpose programming language(s), based on the lambda calculus, and with the ability to manipulate source code as a data structure.
188 questions
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Lexically-scoped Lisp interpreter
Introduction
Here's an interpreter, written in Common Lisp, for a simple Lisp dialect that has some semi-“advanced” features, namely lexical scope with closures, ...
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Lisp-like language interpreter in Python
I decided to learn more about how interpreters work and made a simple Scheme interpreter in Python. I'd like to hear some advice on how I could have written this better, or on the mistakes I've made.
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Destructive quick and merge sort
I've implemented a destructive merge and quick sort in common lisp, but the code feels verbose and highly imperative. I was wondering if anyone could offer guidance on idioms that could make the code ...
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Split a list into two parts
I wanted to split a list into 2 parts, as per the chosen size, first the size and then the list. Example:
(split 3'(1 3 5 7 9))
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Prime number generator in lisp
My implementation is based on the incremental prime sieve described on Wikipedia. I'm relatively new to lisp so I would appreciate any comments on my coding style or on the algorithm.
The below code ...
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Installing packages when needed
I decided to create a portable Emacs config and install packages I use if it's necessary on a fresh computer.
Here is what I've done:
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Hide your text with colorful blocks in secret(-mode)
Motivation
While working on a completely unrelated task, I wanted to share a screenshot of my current Emacs frame, but not of the actual text contents. And while GIMP's pixelate filter did the job, I ...
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Tower of Hanoi in Racket
I'm in the early stages of learning Racket, and decided to have a go at the tower of Hanoi. I did this without any reference whatsoever, so everything is up for review, including the algorithm as well ...
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Count complete trips to the basement and back to ground floor
An elevator starts on the ground floor 0 and moves up or down by one floor at a time as described by an input string travel. ...
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LOVE2D-based grid-movement rhythm game in Fennel
This is the initial skeleton for a short game written in Fennel for a Jam event. It runs sensibly, but I want to know if I'm missing something that could make the code more elegant as it's a bit ...
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WOMOIWIW: What Org-mode Opens is What I Want
Motivation
Previously, on the Emacs stack exchange:
In Org mode, when I open a link (C-c C-o) [...] [that] contains a wildcard, such as file:3_o*.pdf, Emacs opens ...
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define a lisp function, that takes fsm , a transition and state-index and return the state obtained by the transition from the state
The state machine has the below specifications
(defparameter *test-machine*
(make-fsm
:alphabet '(a b)
:table '((2 1) (0 2) (1 0))
:initial 0
:accepting '(2)))
...
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Deque class in Common Lisp
I created a library with two CLOS class to implement a deque structure similar to the one available in C++, plus a few Lisp-ian twists. The two classes are node, ...
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Lispy code? Palindrome of product
My answer to Project Euler problem 4 (largest palindrome of product of two 3-digit numbers) is below.
Please suggest improvements, style changes, indentation, commenting, naming, ...
And nitpicks are ...
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Lispy code? Prime factors of a number
My answer to Project Euler problem 3 (largest prime factor of 600851475143) is below.
Please suggest improvements, style changes, indentation, commenting, naming of "objects", ...
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1
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Lispy code? Sum multiples of 3 or 5 up to 1000
I've started learning Lisp one more time (I seem to do this every couple years); my experience is with C, basically. I attempted to solve the Project Euler problem 1:
If we list all the natural ...
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Racket code to find missing ranges
I'm doing some toy problems in a variety of languages and wanted to do the following in Racket Lisp.
Given a sorted integer array nums, where the range of elements ...
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My implementation of Clojure's assoc-in
This is my implementation of Clojure's assoc-in function. I am looking for tips on making it more idiomatic and in general, better.
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(Lisp in (Rust))
I loved Norvig's Lispy, and made the first version of it in Rust, to learn Rust. I would love your thoughts :)
A few specific questions:
Is there a way to write ...
4
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2
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Check for pangrams in elisp
I'm trying to find pangrams ie sentences that contain all the letters of the alphabet, for instance "The quick brown fox jumps over the lazy dog".
I'm an absolute beginner in elisp, and it ended up ...
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2
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Parsing infix expressions in Clojure
I'm trying to teach myself Clojure by reading the Brave Clojure book online, and at the end of Chapter 7 there is an exercise to parse a mathematical expression written as a list in infix notation to ...
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Edis: Emacs driven indentation script
Motivation
I recently picked up Emacs. As part of the process, I've started to configure the editor to fit my needs with Emacs Lisp. The Elisp indentation rules are still foreign to me, so I pretty ...
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Binary search tree insertion in Racket
I am learning Racket and implemented a BST insert function (insert tree n) where the format for a BST node is ...
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Implementing a tree parsing function
I've solved an assignment a week ago, which is my first assignment using Lisp.
Tasks:
Task 1:
a. Given a tree as recursive lists, print the tree in breadth first order.
b. Given a tree like in ...
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2
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A simple Tic Tac Toe game
I am trying to learn some Common Lisp, except basically all of my computing background is the C family of languages. So, I'm starting small. I have made a Tic-Tac-Toe game, and I am looking for some ...
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Recamán's Sequence in Racket
I just started learning Racket as my first lisp dialect so after getting used to the syntax I implemented the Recamán's sequence.
Apart from the style, I'd also like to know if my code is a linear ...
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2
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Returning the prime factors of a number
I am trying to create a function prime-factors that returns the prime factors of a number. To do so, I created is-prime function,...
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1
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Storing facts for logical questions
I am writing a crude artificial intelligence program. I am happy with my program's ability to file away new word in ways that will allow logic to be done on them. Before I start expanding the logic ...
4
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1
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lisp-koans Greed implementation
I have implemented Greed as part of the lisp-koans extra-credit challenge.
I am seeking some general feedback with respect to Common Lisp style, appropriate use of language features, and so forth. ...
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2
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Generate list of shape in Lisp
I quickly created this function in Lisp that resembles
numpy.random.randint(low, high=None, size=None, dtype='I')
The goal is simply to have a function that ...
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Axiomatic Lisp interpreter in C
This is not obfuscated. Or at least, that's not the intent. Let me try to address that concern straightaway. The goal here is brevity in the vein of Strunk&White. Nor is this codegolf, although ...
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Lisp Interpreter written in JavaScript
I had a task to reduce my Lisp Interpreter from 400 lines to 120 lines. I was able to bring it down to 255 lines without including newline after every function. I'm not able to figure out where I can ...
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SICP - exercise 1.7 better end test for square root approximation
Here is exercise 1.7 from SICP:
Exercise 1.7
The good-enough? test used in computing square roots will not be very
effective for finding the square roots ...
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Generating lists of sequences of specified lengths
I'm writing a program that uses a Genetic Algorithm to "intelligently brute force" our schedule at work. We typically have issues with creating schedules, so I thought using my new GA library to ...
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(SBCL) ASCII Game of Life
I'm implementing Conway's Game of Life in Lisp to familiarize myself with the language, with the eventual goal of hosting it on a website with a pretty GUI. I'm a hobbyist and inexperienced (this is ...
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Minimal substring with all characters contained in string
I was given following task in the interview:
Given a string, find shortest substring in it that contains all of the different characters contained in the original string.
Here is my solution in ...
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Reinforcement learning example (chap. 1) from Sutton's book
I ported the Lisp Tic Tac Toe code from Chapter 1. to Haskell. The original code repo is down for some reason.
I believe I have completely rewritten that in Haskell (Less functional than one would ...
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3
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Invert the bits of a non-negative integer in Common Lisp (SBCL)
I'm doing code challenges to learn Common Lisp. I'm trying to invert all the bits in any given positive integer.
My current solution does it the math way, by recursing on a number, dividing it by two,...
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A heart.lisp I wrote with my 6 year old daughter
Is it possible to improve this program somehow? It will probably be more convenient to suggest edits as forks of this Gist.
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Definition of power functions
I needed to write a simple function that could raise a value x to the n'th power. I found out I could write this function in 2 ...
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2
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Project Euler #2 (classic) - Sum of even fibonacci numbers below 4 million
I'm looking to use LISP as best I can, not just get the right answer. This is very early on in my LISP career so feedback is welcome and exciting! Recently asked about Project Euler #1, got some ...
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Sum of all multiples of 3 or 5 below 1000 (Project Euler #1 - typical)
I'm learning LISP and am starting with Project Euler. I would love some initial feedback on my LISP code for this simple task.
I know it spits out the correct answer, but what I'm not sure about is ...
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0
answers
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Computing nth roots of a number - SICP exercise 1.45
From SICP
Exercise 1.45:
We saw in 1.3.3 that attempting to compute square roots
by naively finding a fixed point of x/y does not converge, and that
this can be fixed by average damping.
...
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Approximating pi/4 using Wallis Product - SICP exercise 1.31
From SICP
The sum procedure is only the simplest of a vast number of similar
abstractions that can be captured as higher-order procedures. Write an
analagous procedure called product that ...
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Pascal's triangle in mit-scheme
As suggested by the name of source file (ex1.12.scm), I just started learning mit-scheme by reading SICP. In Exercise 1.12, I'm asked to "compute elements of Pascal'...
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Highest number in a list with Racket
I am trying to build a function to find the highest number in a list without using the built-in functions of "apply" and "max".
I created the following code:
...
user122340
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GUI implementation with Racket
I am studying the book Realm of Racket.
On chapter 5, there is a challenge:
Find an image of a locomotive. Create an animation that runs the locomotive
from just past the left margin to just past ...
user122340
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Converting a sentence string to a number in Scheme
I wrote a scheme procedure that converts strings such as "Two hundred and fifty" into a number like "250" that I can use in math calculations (It's for some Natural Language Processing project).
Is ...
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Reverse the order of a list in Racket
I am using the SICP book. There is an exercise in which you need to create a function that will receive a list as an argument and return a list with the same elements in a reverse order.
I know there ...
user119912
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“Guess My Number” with Racket
I am using the book "Realm of Racket" which was written by the people behind the Racket and Dr. Racket projects. It is a great book based on games, similar to the famous "Land of Lisp".
The first ...
user119912