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.
3
votes
1answer
47 views
ANFIS network based on Sugeno model I
I've been learning Common Lisp lately and I've implemented ANFIS network based on Sugeno model I.
Network layout and details can be read in these slides by Adriano Oliveira Cruz.
I use sigmoid as the ...
2
votes
3answers
77 views
Recursion vs. iteration in Lisp macro
I've been programming Clojure for a little while and recently started learning Common Lisp. One of my favorite things about Clojure is the threading operator ->, ...
6
votes
0answers
100 views
WebSocket-based API library in Racket
I've developed a library in (typed) Racket that wraps a WebSocket-based API. The API itself is very simple—it operates via a series of three-letter commands optionally followed by a JSON-encoded ...
1
vote
0answers
57 views
How common is the use of closure in Lisp?
I'm writing a little tool for mangling MP3 collections and, as a challenge, I decided to write in in Hy, a dialect of Python that uses Lisp syntax. Like every good developer, I wrote out my list of ...
2
votes
2answers
187 views
Computing pairwise bitwise OR in a list of bit-strings
I am trying to solve this problem using Clojure:
You are given a list of \$N\$ people who are attending ACM-ICPC World
Finals. Each of them are either well versed in a topic or they are
not. ...
2
votes
2answers
34 views
Split every vector in a sequence into two parts: old elements that were contained in previous vectors and new elements never before seen
Am I doing it right? Is there some function in the standard library I should be using? This is my first real(ish) world Clojure program…
Input
...
1
vote
1answer
97 views
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:
...
14
votes
1answer
185 views
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 ...
6
votes
2answers
91 views
Getting functional Common Lisp code for handling state in a SDL animation
The following code draws a red rectangle bouncing between the borders of a white display. I'm not particularly happy with the update function:
...
6
votes
4answers
152 views
FizzBuzz - officially now in CLISP
I had to jump on the bandwagon for this one. The task does a great job of helping you learn a language you're unfamiliar with.
So today I present you with my version of the infamous FizzBuzz game in ...
6
votes
4answers
972 views
Finding the sum of all the multiples of 3 or 5 below 1000
As a Lisp (and functional programming) newbie, I wrote the following code that finds the sum of all the multiples of 3 or 5 below 1000, and I suspect that it is lousy:
...
3
votes
2answers
105 views
Creating a repetitive string in Common Lisp
I needed to have a Lisp function that could produce a string of a certain length, created by repeated concatenations of a another string given as argument (so for example by giving 10 and "abc" I ...
5
votes
1answer
54 views
Accessor functions in elisp
I'm writing some simple emacs tools for visual studio solutions.
I've got a function sln-process-csproj-file. This function takes the path to a project, and ...
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votes
2answers
134 views
Generic sequence splitter in Common Lisp
I wrote a function split-seq-by-n which accepts a sequence and a number and splits the sequence into subsequences of length n (the last subsequence getting the ...
10
votes
1answer
1k views
Clojure Neural Network
After reading this article about Neural Networks I was inspired to write my own implementation that allows for more than one hidden layer.
I am interested in how to make this code more idiomatic - ...
3
votes
2answers
59 views
Calculating series of rows to use to play a melody on 5-row Bayan Accordion
This was my first attempt at writing a program in LISP. Can anyone give any guides as to how it could be improved? The multiple loops in best-pattern seem awkward (I'd normally do that in just one ...
2
votes
1answer
93 views
Rewrite apply function to use recursion instead
Probably the hardest part of learning lisp has been to think in the "lisp way" which is elegant and impressive, but not always easy. I know that recursion is used to solve a lot of problems, and I am ...
1
vote
1answer
152 views
How do I avoid eval in elisp?
I have wrote a simple util to submit my code to a online judge site, how to avoid the evil function?
...
1
vote
2answers
62 views
Is using defvar for a non-global variable ok?
I am calling defvar in the middle of a function definition. And so far I've always seen its use, with defparameter for global ...
1
vote
0answers
83 views
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 ...
1
vote
1answer
76 views
A small emacs-lisp snippet for opening a register in another window
I'd like to get some feedback on whether this is idiomatic elisp, whether it's any good, and any small modifications that would be useful. Thanks
...
1
vote
4answers
394 views
Echoing back input in uppercase over a socket with Hy, a Python Lisp dialect
I think I'd like to learn Clojure eventually, but at the moment am having fun with Hy, a "dialect of Lisp that's embedded in Python."
...
4
votes
0answers
137 views
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 ...
3
votes
1answer
345 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 ...
10
votes
0answers
492 views
Connect Four AI (Minimax) in Clojure
I wrote a Connect Four game including a AI in Clojure and since I'm rather new to Clojure, some review would be highly appreciated. It can include everything, coding style, simplifications, etc.
But ...
2
votes
1answer
149 views
LISP - Modify string
I have to write a program that changes a string's vowels, consonants and other symbols into C, V respectively 0. I've done this but I wonder if there is a more efficient and elegant way to do it. ...
1
vote
2answers
294 views
Improving readability of non-recursive depth first search function in Lisp
As a free-time activity in order to learn some Lisp I had to implement depth first directed graph search. Due to large graph size (800K nodes, 5M arcs) recursion-based approach I could devise didn't ...
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vote
1answer
216 views
Proper use of reduce, nested loops
Below is an implementation of Dijkstra's shortest path algorithm. It's input graph is represented as an association list of source nodes to assoc of target node and ...
1
vote
1answer
117 views
How to improve readability of a big lisp function
My main method (remove-random-edge) looks quite difficult to read. I'm new to list, so would appreciate any advice on how to improve the code.
...
4
votes
1answer
144 views
Seeking advice on lispiness of style and approach
I'm new to Lisp and I'm yet to wrap my head around the Lisp way of writing programs. Any comments regarding approach, style, missed opportunities appreciated:
In particular, please advice if I build ...
2
votes
1answer
157 views
Project Euler #35 in Common Lisp
To start with Common Lisp I am doing Project Euler using this language. Usually I manage to solve problems but I am quite sure that my code is not as efficient as it could be in Common Lisp. That is ...
5
votes
1answer
156 views
Pile shuffle of a vector
My goal is to simulate a Pile shuffle of a vector. It takes 2 optional arguments for the number of piles to use and how many times to perform the shuffle.
As this is my first attempt at clojure code, ...
4
votes
2answers
443 views
Combinations of list elements
It was written in Emacs Lisp and requires Common Lisp loop facility.
Can this code be improved? Did I hit any anti-patterns along the way?
...
2
votes
2answers
559 views
Counting Ways to Make Change — Is this good functional/Lisp style?
I have just started learning some Scheme this weekend. I recently solved a problem that goes something like:
...
3
votes
1answer
435 views
Connect Four: Bitboard checking algorithm
I'm rather new to Clojure and so I decided to program a Connect Four for fun and learning.
The code below is a Clojure implementation of this bitboard algorithm.
The whole code can be found here: ...
3
votes
2answers
86 views
simple “if”-less algebraic computation using CLOS
For educational purposes I've tried to implement a simple algebraic OOP example using CLOS. The functionality is as far as I can say as it is supposed to be. The intended approach was to implement a ...
1
vote
1answer
400 views
Solution to 99 lisp problems: P08 with functional javascript
Solution to 99 lisp problems: P08, with functional javascript
If a list contains repeated elements they should be replaced with a single copy of the element. The order of the elements should not ...
4
votes
1answer
203 views
iterative copy-tree in lisp
The common lisp function copy-tree is often implemented in a recursive way,
and thus is prone to stack overflow.
Here is my attempt at writing an iterative version, one-pass, no stack,
no ...
7
votes
1answer
554 views
Clojure TicTacToe (Logic, no Gui)
I whipped this up last night and was wondering if anyone had any thoughts/comments on it; for example, on:
Code organisation
Coding style
Other improvements
Semantic errors
All feedback is ...
1
vote
0answers
79 views
Implementing buffered channels in Guile
I was looking for a way of doing simple message passing in Guile and found some references to the module (ice-9 occam-channel) which is a pretty nifty, but undocumented, module for occam-like ...
1
vote
2answers
133 views
4
votes
4answers
2k views
Finite State Machine code
I have been making this FSM today. However, as this is probably the biggest practical program I have ever written in CL, I don't know if there are some things that could be improved, or if using a ...
3
votes
2answers
326 views
Searching for repeated characters in a sequence of characters
The following code solves this problem:
The 3072 characters below contain a sequence of 5 characters which is
repeated. However, there is a twist: one of the sequences has a typo.
To be ...
7
votes
2answers
162 views
Write a procedure stream-limit that finds
From SICP:
Exercise 3.64. Write a procedure
stream-limit that takes as arguments a
stream and a number (the tolerance).
It should examine the stream until it
finds two successive elements ...
1
vote
0answers
147 views
Write a definition of a semaphore in terms of test-and-set! operations
From SICP:
Exercise 3.47. A semaphore (of size
n) is a generalization of a mutex.
Like a mutex, a semaphore supports
acquire and release operations, but it
is more general in that up to n
...
1
vote
0answers
148 views
Write a definition of a semaphore in terms of mutexes
From SICP:
Exercise 3.47. A semaphore (of size
n) is a generalization of a mutex.
Like a mutex, a semaphore supports
acquire and release operations, but it
is more general in that up to n
...
3
votes
0answers
123 views
Representing a queue as a procedure with local state
From SICP:
Exercise 3.22. Instead of
representing a queue as a pair of
pointers, we can build a queue as a
procedure with local state. The local
state will consist of pointers to the
...
4
votes
1answer
213 views
Examine a list for cycles
From SICP:
Exercise 3.18. Write a procedure that
examines a list and determines whether
it contains a cycle, that is, whether
a program that tried to find the end
of the list by taking ...
1
vote
0answers
345 views
Correctly count the number of pairs in an irregular list structure
From SICP:
For background, here is exercise 3.16:
Exercise 3.16
Ben Bitdiddle decides
to write a procedure to count the
number of pairs in any list structure.
...
1
vote
1answer
241 views
Order of evaluation of function arguments
From SICP:
Exercise 3.8
When we defined the
evaluation model in section 1.1.3, we
said that the first step in evaluating
an expression is to evaluate its
subexpressions. But we never ...
