Questions tagged [f#]
F# is a succinct, expressive, and efficient functional and object-oriented language for .NET
364
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Thread-safe hashset that enumerates according to insertion order
According to the .NET documentation, HashSet<T> does not maintain order when enumerated so I implemented my own using F#.
Can anyone help review if this is ...
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Finding the first position in a number spiral that's bigger than a target
I'm working on day 3.2 of Advent of Code.
The task for this challenge is to create a number spiral where each element is the sum of all of its neighbors. Using this spiral, we have to find the first ...
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Creating and manipulating a map for a text based game F#
I have put my whole code so far below, but what I am most interested in is how best to implement the map and utilise it. Any tips on organising my code and keeping it clean would also be greatly ...
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F# Finding the powerset of a set
I have this function which takes a list as input and computes the powerset.
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Brainfuck interpreter in F# (by a C# developer)
I'm a C# developer learning F#. I have a lot of questions about practices and principles within the code. I would like to know what a "native" F# developer would've done differently.
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Partitioning a list in F# based on whole group characteristics
I only started programming in F# yesterday, so I've not yet discovered what idiomatic F# actually looks like.
The first task I set myself required partitioning a list into smaller lists but where the ...
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F# functions implementing polynomial arithmetic [closed]
I have a couple of functions for doing basic arithmetic on polynomials.
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Area under curve and its volume as solid of revolution
I would like to know if there is some more "elegant" way to write these 3 functions. Any tip or idea is welcome.
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Validate a password mostly to NIST-2017 standards
I have an application that needs to validate user passwords to a very reasonable custom validator, which is heavily based on NIST-2017 requirements. The validator intends to satisfy the following ...
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F# Observable.subscribeWeakly implementation
In this SO question I needed an observable subscription function that can be used kind of like Observable.subscribe, but that does not keep a strong reference to ...
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Wordpress RSS Parser
Follow Up to my earlier question.
This is an RSS Parser intended only to parse the feed Wordpress provides (and even then, only what I actually want to display on my website). ...
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RSS Parser for Blog Feed
I'm building an RSS feed parser so, later, I can retrieve recent blog posts on my word press blog and display recent posts on my other website. This code isn't intended to implement the full RSS spec. ...
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Concurrency using immutability
I was watching the following video about software transactional memory(using a package that maintains an access log). At the moment I am trying to learn about concurrency with shared memory and ...
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Is This F# Recursive Example Tail Recursive?
I have a payment/lockbox file archiving utility that is called several times per day and with different parameters depending on the files that need archiving.
I know I can flatten ...
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Minimise function with single minimum and no maximums
I'm learning F#. I wrote a function to minimise a function with a single minimum and no maximums. At the bottom I test it on Math.Cos.
What do you think? I've wrote it pretty much as I would in an ...
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Counting letter frequencies from an input file
Out of pure curiosity, I decided to create a short F# script to calculate the letter frequencies based on the input file. Everything works smoothly and as I would expect. My questions regarding my ...
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Questions on F#'s loop and cont [closed]
The following tail-recursion example is taken verbatim from Chris Smith's Programming F# 3.0. If this is not the appropriate forum for this post, I will gladly move the post to the appropriate place. ...
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Functionally find the index of the minimum value in an array
I come from a C#/JavaScript/TypeScript background and am learning F# by implementing fundamental algorithms. This is finding the minimum value in an array:
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Implement array element swap in a functional language
Sorting algorithms involve swapping element positions in an array. This is my implementation of swap:
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Immutable recursive binary search of a generic array
I am new to F#. Is the following code, which represents about three hours of work, a canonical way to achieve binary search? If not, how can it be improved for readability and maintainability?
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Learning F# with Prime Factorization
In my quest to learn F#, I implemented Prime Factorization.
First, the code:
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Immuitable recursive linear search of an array of string
I am new to F#. Is the following code, which represents about three hours of work, a canonical way to achieve its goals. If not, how can it be improved?
For instance, can we provide a default value ...
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Caesar cipher in F#
I'm trying to broaden my horizon by learning functional programming (coming from OO, specficially C#). For this, I'm implementing some small problems to get a feeling for the language. One of my first ...
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Calculator for magic item creation in RPG
I have created a simple calculator that will assist in creating magic items from the tabletop RPG Pathfinder. Here are the full requirements, and if you want a more concise version, here is a player ...
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Searching files in directory with various filters
Requirements
Note: the requirements are invented by me for practicing functional programming.
Functional Requirements
Given a directory, all files below the directory (and its sub directories) ...
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F# binary reader
I've written a fairly simple script in F# which reads structured data from binary. I've avoided using the built-in .NET BinaryReader class because it's stateful in that it maintains its index in the ...
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Reading numbers from console until input isn't a number
I want to read N numbers (Nmax = 100) from console into a list. N is not known, but the first input that is not a number may break the reading process... However the solution should be as simple as ...
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Event sourcing using functional programming
Is this a satisfactory implementation of event sourcing using functional programming?
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Compact game of life implementation
I am learning F# and implemented Conway's Game of Life as an exercise (There are also other implementations on CodeReview). I have tried to forget all my object-oriented background and practice "...
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Simple INI and command-line parsing, functional programming edition
I'm in the beginning stages of rewriting the model layer of my VBA Sync Tool in F#, to better learn functional programming. So far I've defined:
A public ...
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A* Algorithm in F#
Inspired by this post I looked up A* on wikipedia and went on with my own implementation as seen below where I try to mimic the pseudocode on Wikipedia but in a recursive manner.
I would like any ...
user73941
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Pool Checkers with AI
I recently added Pool Checkers to my Checkers game. My main concerns are about how I manage calling the correct variant in my PublicAPI functions. Because this is ...
user34073
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answers
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F# implementation of the A* algorithm round 2
This is my second attempt at implementing the A* algorithm using F#, the first one is here.
What I changed:
I removed the Node class and added two records named ...
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F# implementation of the A* algorithm
This is my first attempt at writing something useful in F# and in a functional way in general. I would appreciate if you could point out any issue, even details, as I'd like to put all the bad habits ...
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F# program to generate a Map of substrings frequencies
I wrote the following F# program that takes an input txt file and create a Map that contains all possible substrings of size N and their frequency in the file.
In other words if I call the program ...
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Compute a value (and update a CSV record), based on prior value
The F# code below embodies the two specific questions I have. It is part of a working transformation utility, the entirety of which, including sample data, is in this gist:
http://bit.ly/2i3kUwF.
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American Checkers with AI
This is the third question in the series. Number 1 had most of the official two-player rules implemented, and Number 2 was the basic UI. This one has the complete two-player rules implemented, an AI ...
user34073
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Navigating a bounded 2D list (Advent of Code, Day 2: "Bathroom Security")
I'm trying to solve the following Advent of Code problem in F# for practice.
Description of problem (can be found here):
Basically, there's a 'key pad' that I need to figure the combination to. To ...
user124336
11
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1
answer
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American Checkers
I am implementing the logic for a Checkers game in F#. I am writing my code in a library so it can be called from any UI provider, and am trying to do it in good FP style. I currently have the ...
user34073
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1
answer
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Wild and changing business rules implemented with functional programming
I attempted the Business Rules Kata. Here's a video overview.
However, I am not confident that going functional is a good strategy for the following objective:
How can you tame these wild business ...
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Probabilistic Matrix Inspection - Suggested by a paper, implemented by me
I have read this paper and I actually found it interesting.
This is an attempt to implement the proposed algorithm. I would like to know:
Is my algorithm correct by what is discribed in the paper?
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F#unctional Immutable Trie (Prefix Tree)
I've created the following implementation of a trie in F# as an effort to learn the language. I would like to know what could be done to make it more idiomatic. Any other pointers are welcome as well.
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Word splitting / text parsing with consideration for quotes
Is the MoveNext operation inefficient here? I really just want to increment an index. Originally, I had a mutable variable locally in ...
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MailboxProcessor and prioritized messages
I'm trying to create an agent that holds on to Data and does further work with it upon receiving the Work message. ...
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1
answer
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Print diamond of any size
I'm trying to print a diamond of asterisks of an arbitrary size. I'm new to F#, so I'm interested in virtually any feedback, but especially adherence to idioms, convention, and functional orientation.
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F# Active Pattern with Poker and Playing Cards
From this question and John Palmers answer about active pattern I discovered a gap in my knowledge about F# and took the challenge to code me into some level of understanding this technique.
The ...
user73941
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Reporting the highest satisfied poker hand in F#
I'm learning F# by doing various small projects. One of them is a problem where the program reads Poker hands and rates them. It's Texas Hold'Em, so for each player it tries every five card selection ...
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