Questions tagged [f#]
F# is a succinct, expressive, and efficient functional and object-oriented language for .NET
332
questions
6
votes
2answers
619 views
Console input prompt loop in F#
I'm learning F#, starting with baby steps. Is there a way to write this code in a more succint way, while keeping the same semantics? Maybe by using a Seq or ...
1
vote
1answer
341 views
Parsing .PLY file using F#
I'm fairly new to F# and have written a program to parse PLY files - this is however done in an imperative way with mutable values and as far as I know that should be avoided in functional languages.
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4
votes
2answers
68 views
Breaking lists into subgroups in F#
I'm starting to play with F# to do some data parsing and I was able to create a function to group an array of string into sub groups. The code looks like this:
...
5
votes
1answer
596 views
Anagram finder in F#
I've been learning F# for a month or so and I'm wondering how good my "functional" aspect of coding is. When I first started, I did this using an iterative approach with a lot of <- and mutables ...
3
votes
0answers
58 views
SqlDataConnection update method
I'm using Microsoft's SqlDataConnection type provider. However, the only way I've seen to update a row in the database is to use something similar to this where it updates mutable values:
...
3
votes
2answers
218 views
Heightmap generation using midpoint displacement
I am writing a program to generate a height map following the midpoint displacement algorithm (somewhat similar to diamond-square).
I'm at the point where I have a recursive program that paints the ...
2
votes
0answers
86 views
Blocking Memory Queue
This is a FIFO blocking memory queue in F# to be used as a component in a logging library.
...
9
votes
2answers
212 views
Unit testing F# code without using an existing test library (MSTest, xUnit, etc.)
I know I can probably use MSTest (I'm under Linux without an IDE so maybe not?) or another unit testing library, but for a small project I decided to write my own unit tests without resorting to a ...
0
votes
1answer
78 views
Converting height map bitmap to json
This is my first F# program.
It's a command line utility that takes a parameter containing a path to an height map bitmap and prints out this height map converted to JSON format.
...
4
votes
1answer
258 views
FizzBuzzWoof in F#
I'm learning F#, and have challenged myself to write a good functional implementation of FizzBuzzWoof. (The difference from "standard" FizzBuzz is that any number that either is divisible by or ...
4
votes
2answers
710 views
Dijkstra algorithm implementation in F#
I'm trying to implement Dijkstra algorithm in F# for finding the shortest path in a undirected tree using a heap.
I've used the type PriorityQueue found here and the code can be found here.
...
3
votes
1answer
228 views
F# cache manager
This is a port of a C# cache manager we use to F#. This is my first F# code, and I've tried to make it as idiomatic as possible. I would appreciate input on style, performance considerations,...
3
votes
1answer
312 views
Factory pattern in F# for a web scraper
I'm trying to learn F# by creating a little web scraper that will do custom scraping based on the url domain. For this, I need to create and select the correct kind of scraper. I figure I would use a ...
3
votes
1answer
220 views
Project Euler Q7 - 10001st prime
The problem is (source)...
By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
What is the 10001st prime number?
This is my second attempt at ...
1
vote
1answer
42 views
Create a collection of binaries with random set positions
I would like to create a collection of binaries with n set bits and total length should be between n and 31; also those set bits ...
2
votes
1answer
43 views
6
votes
1answer
159 views
Project Euler Q2 - Sum of even Fibonacci numbers
I'm very new at F#, and am using Project Euler to help me learn. Question #2 kept me going for a while, as my initial attempt at an answer was very slow and inelegant. Then I learnt about Seq.unfold, ...
5
votes
1answer
98 views
Solution to Project Euler problem 5 (LCM of 1 to 20)
I'm an experienced C# developer trying to teach myself F#. I spent a day or 3 reading throught the F# wikibook trying to get to know the syntax and F# fundamentals.
As an exercise I'm trying to go ...
4
votes
2answers
240 views
F# code to check whether there are three same digits within a given number
I came across this problem by accident and gave it a go. I think my solution works as it has passed all the unit tests I wrote. Given I just started learning F# a couple of weeks I would love to have ...
5
votes
1answer
143 views
Solving adventcode day 6 puzzle: toggling lights in a grid
I have solved the day 6 adventcode problem:
--- Day 6: Probably a Fire Hazard ---
Because your neighbors keep defeating you in the holiday house
decorating contest year after year, you've ...
9
votes
1answer
540 views
Prime factorization in F#
In the pursuit of learning F#, I have been working through some Project Euler problems.
This is my solution for problem 3:
...
4
votes
1answer
68 views
Finding the largest prime factor
As many people will undoubtedly recognise, this is a question in a well known series of problems that I won't name ;)
It's been a long time since I've written any F# and I'm not sure I've ever come ...
7
votes
1answer
112 views
World's worst Christmas tree
Inspired by this question, I decided to grow my own fractal tree.
The problem is: given an integer \$n\$, \$0 \leq n \leq 5\$, print the \$n\$th iteration of the fractal tree. The tree is probably ...
5
votes
2answers
163 views
Constructing a simple tree with ASCII in F#
This is just a basic HackerRank challenge I was working on to better understand F#. Its purpose is just to print a tree that has a straight 'trunk' of \$n\$, splits into 2 branches which diverge to \$...
15
votes
4answers
848 views
Project Euler 6: Difference between sum of squares and square of sum
I've created a (very) simple solution for Project Euler problem 6:
Project Euler Problem 6: Sum square difference
The sum of the squares of the first ten natural numbers is,
$$ 1^2 + 2^2 +...
6
votes
1answer
497 views
Project Euler Problems #1-#5
Since I've been playing with F#, I decided to try my hand at implementing some of the Project Euler problems, and I've been having a blast doing it. (f#-is-fun)
So, I'm going to list all the Project ...
10
votes
2answers
350 views
F#zzBuzz: Learning the easy way
So I made a quick programme in F# to do FizzBuzz, I'm trying to learn more languages, so I figured I'd do something functional for a change. (Haskell is also on the list.)
FizzBuzz is pretty self-...
3
votes
2answers
75 views
Find unique variants of a product
I am writing a piece of code that returns all the unique variants that a product is available in for an ecommerce app. For example, a shirt product can be available in different colors, sizes, and ...
2
votes
1answer
88 views
Digit Power Sum with BigInteger
This is my 1st F# program so I'm open to any and all criticism on my syntax and the way I approached the problem.
Challenge
Project Euler 16: Power Digit Sum
2^15 = 32768 and the sum of its digits ...
3
votes
2answers
62 views
Summations and products and factorials oh my
The proper title of this question should be "Summations and products, and factorials oh my!".
After getting quite a bit of useful feedback on this question from @mjolka, and a comment, I decided that ...
3
votes
1answer
170 views
Trying to do Type-Driven Development in F#
I've been wanting to try out F# for some real world programming so I decided to try rewriting a program that is being used at work.
It can be reduced to a few steps:
Get report templates.
In this ...
2
votes
1answer
96 views
Summations and products in F#
I was bored, and looking to do something that involved anonymous functions, and it was suggested by @Quill, that I create a summation function. I decided to also include a product function as well to ...
3
votes
1answer
74 views
Renaming video files based on episode title lookup
I'm new to F#, so I've ported an old Python script I have to F#. It scans a directory for files named something like Game.Of.Thrones.S01E02.xvidblahblah.mp4 or <...
1
vote
1answer
56 views
Creating a structured category list in F#
This takes a list of categories and organizes them into a tree-type structure based on their parentId. This code works, but is obviously a little over-complicated. ...
1
vote
1answer
108 views
5
votes
1answer
138 views
Lindenmayer System String Generator in F#
Lindenmayer Systems or L-systems are fractals that can be constructed by applying replacement rules to a string for a certain amount of iterations. For example:
...
10
votes
1answer
680 views
Small game written in F#
I'm trying to wrap my head around F#. I'd like your honest opinion about this simple game source code that I wrote. Rules are simple:
Every player has soldiers and territory
Player can recruit ...
4
votes
1answer
134 views
Utopian Tree in F#
This is the Utopian Tree in F# (from HackerRank)
The Utopian tree goes through 2 cycles of growth every year. The first
growth cycle of the tree occurs during the monsoon, when it doubles in
...
6
votes
1answer
116 views
Hello Functional World: Counting occurrences of each letter
Coming from a OO (C#) background, I am trying to learn some FP. To help me transition, I am trying to learn F#. I am taking baby steps.
I set myself a simple challenge to count the instances of each ...
5
votes
2answers
558 views
Add two numbers stored as a list in F#
I am solving the following problem:
You are given two lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two ...
6
votes
1answer
772 views
Game of life in F#
First attempt at doing anything F#-y from a very heavy C# background, think I've grasped the fundamentals of FP, but always good to get other eyes on it:
...
8
votes
2answers
957 views
Mock/Stub out filesystem in F# for unit testing
I'm looking to do some basic verification testing on my functions that write to the filesystem.
I took a hint from here on how to mock out the filesystem using an interface, but I'm kinda bummed on ...
4
votes
2answers
383 views
Reverse Polish Notation in F#
In my question to learn F#, I've decided to get one step closer to creating a programming language, and implement this simple Reverse Polish Notation "interpreter" of sorts.
It does not allow for ...
7
votes
1answer
486 views
Efficient generic type conversion between numeric types in F#
It's easy to write a function that adds two ints in F#:
let add x y = x + y
Actually, it's the same as:
...
10
votes
2answers
199 views
F# inventory system - Part 2
I've refactored my previous inventory system, and added a few features like removing items from the Inventory class, easily obtaining the current selected item ...
7
votes
1answer
535 views
F# inventory system
To learn F#, I've implemented this very simple inventory system. While I'm proud that that it's my first program, and that it works, there are still a few areas that I'd like tips on, namely these:
I ...
10
votes
2answers
6k views
Reading input from console in F# (as a sequence of lines)
Consuming input line-by-line until the end is often useful. In C# I would write the following loop:
while ((line = Console.ReadLine()) != null) {
// ...
I ...
3
votes
1answer
494 views
Building and flattening a dependency graph
The Problem
Given a list of dependencies ('a * 'a) list where the first item has a dependency on the second item, construct a dependency graph and then 'flatten' ...
3
votes
1answer
62 views
Projecting future positions
My code takes a starting position (which must be completed) and a list of updates (each element of which is optional). It then projects future positions, using the appropriate value from each update, ...
5
votes
1answer
412 views
Sudoku game logic
I am trying to create a Sudoku game in F# and I'm having a bit of trouble with the file reading and writing. But since I've also just started programming in f# I would like to check if my thinking is ...
