Questions tagged [f#]

F# is a succinct, expressive, and efficient functional and object-oriented language for .NET

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votes
2answers
69 views

Solving the game Set in F#

I was playing the game Set online, and thought it would be a good exercise to write an F# script to find all of the sets for me. The rules of set are as follows: A SET is 3 cards for which each ...
3
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1answer
65 views

F# Binary Tree and Tree Traversal

So for an side exercise on exercism I implemented a BinarySearchTree. I was confident in implementing the creation of the binary tree. But I'm very unsure about the traversal of the tree. So I came ...
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0answers
25 views

Functional Dependency Injection Abstraction

The F# web-development framework Giraffe supports a functional style of Dependency Injection using a form of the Reader monad, as explained in this GitBook. I would like to use this pattern more ...
2
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1answer
68 views

Assigning jobs in a functional style

I'm new to F# and functional programming in general (coming from an object oriented background). I just wanted to get some criticism on an algorithm for assigning jobs to crew members. I want to be as ...
3
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0answers
53 views

Flashcard Website

In my endeavor to learn Angular, I've created a flashcard site with an F#/Mongo backend. As I'm new to Angular, I'm going to post everything; any and all feedback is welcome. First, some pictures of ...
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0answers
81 views

Simple queue on F#

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0answers
48 views

F# method to insert, update, or delete events in a dictionary

I have the following code: ...
0
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1answer
64 views

Asp.net middleware [closed]

This code is asp.net core middleware written in f# and called from c# for a blazor server-side app. How can this be made more efficient if any in regards to the async code. F#: ...
2
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0answers
77 views

Sanitize input for a “robot on a grid” kata

I have the following piece of code which is FSI tested and works. However, I want to trim it as much as possible (not only the comments, which are there for my own future reference) and make it as ...
4
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2answers
86 views

Query a product from a list of brands

I am quite new to F# and just wrote my first program. It checks if the query exists in the brand list and returns the matching brand. Query is the string you are searching for in the brand list. So ...
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0answers
43 views

F# and UDP server/client

I have a simple UDP client/server code looke like: ...
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0answers
37 views

Photo rename by Exif date and group into folders with a threshold

I wrote this tiny F# project yesterday, but I am a bit rusty and I would like to know if there is anything I can refactor and make more elegant. ...
2
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0answers
37 views

F# XML Generation in .NET Core: XmlSerializer or XmlProvider

I am working on SEPA XML generator in F#. I developed two solutions that are roughly equivalent, one relies on the XmlSerializer while the other relies on ...
1
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1answer
62 views

Idiomatic way to write proper F# (x)unit + fsunit tests?

I am writing some unit tests using XUnit in F# and I am wondering what is the most idiomatic way in the F# sense to write them. Let's start a simple case: ...
6
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2answers
207 views

Asynchronous IBAN API with validation

I am working on an iban api which is about saving the iban of some members after (iban validation) in a database. The code is split between Domain (entities, behaviour for iban validation), Database ...
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0answers
48 views

F#, Timer and propperly removed ElapsedEventHandler

I have a simple method that receives messages from bus, builds response and send it back, and it looks like: ...
1
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1answer
59 views

F# Simple message reader using TCP

I have a review request about this part of the code: ...
4
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1answer
75 views

Binary Trie in F#

I have this little exercise writing a binary trie in F#. In C# it can be done in few lines, but here it became more complicated than I had expected (especially the ...
4
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1answer
78 views

Convert to and from variable length quantities

As part of small MIDI library i've implemented the conversion of a VLQ (variable length quantity) for byte[] -> bigint and ...
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0answers
103 views

Async in Railway Oriented Programming in F#

In F# the Railway Oriented Programming pattern can be implemented synchronously using the Result<'t,'terr> type as result value for functions, so they can be ...
6
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1answer
56 views

F# pattern matching to determine the state of a bank account based on past events

I am writing an event sourced system in which I need to have the state based on the events that already occurred for a given bank account. The events are defined such as: ...
5
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2answers
125 views

Tcp server messenger awaiter in f#

Hi I have a simple tcp server, and that server receives messages with specific length so basically i need to wait for TcpClient to fill buffer with that amount of data, and it works. But I am not ...
2
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0answers
64 views

A simple functional F# wrapper for EasyNetQ

This is my first attempt at creating a small module to wrap the .NET library EasyNetQ in F# to make it more functional. I am pretty new to F# and I would like to get feedbacks on everything: types, ...
4
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2answers
99 views

F# wrapper to generate SHA256 signature for a file

I've created the following module to allow me to generate a SHA256 signature for a file. (In real life this is used to verify an image file hasn't been amended). The cut down code looks like this: <...
4
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2answers
140 views

Roman Numbers - The Functional Way

Yet another exercise in converting values between the decimal and roman number systems. I have tried the functional way. Any comments are welcome - but I'm especially interested in answers focusing ...
3
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1answer
43 views

Concise way of “updating” element in nested collections

Imagine simple game: ...
2
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1answer
65 views

F# parse data and calculate sum

I decided to play with F# and found simple task on Codewars. The task is sounds like "Calculate Sum/Mean/Avarage for selected City". I decided to calculate only Sum. My solution is horrific. I would ...
2
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1answer
65 views

Project Euler Problem #102 in F#: counting triangles that contain the origin

I've recently decided to get into functional programming with F#, and decided to learn the language through Project Euler. The following is my implementation of problem 102: Problem: Three ...
3
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1answer
236 views

Convert bitcoin value based on exchange rate from JSON API

I’m learning F# and trying to find a more ‘functional’ way to code a simple program that retrieves the price of BTC and calculates the EUR value of an amount of Bitcoin. ...
2
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0answers
42 views

Creating idiomatic and efficient method to stream large JSON file

The purpose of the code is to efficiently stream JSON items from a large file. I am wondering if this is efficient and decently idiomatic. Not sure how I could eliminate the while loop either. ...
4
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1answer
57 views

Analyzing spoke overlaps during rotation: Round 2

Round 1: Analyzing spoke overlaps during rotation I previously posted this question, but I've changed a lot of the code since then. There was a mention of the previous being a bit mixed up, and ...
6
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1answer
59 views

Analyzing spoke overlaps during rotation

For a personal project that I've recently started I have to analyze the rotation of two shapes with sets of spokes, where the spokes are evenly-spaced, and split into a given number. That is, if I ...
6
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1answer
80 views

Verifying that three cards make a “Set”

The game of Set involves cards with four properties: number, symbol, shading, and colour. Three cards make a "Set" if the property is either all the same or all different across the three cards, for ...
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0answers
37 views

Blockchain implementation in F#: Wallet

Introduction This is Part 3 of my F# blockchain implementation. Previous parts: Block and Blockchain Transactions Code In this part I am implementing a wallet functionality. The code is based on a ...
3
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2answers
570 views

Advent of Code 2018 day 1 part 2: find the first aggregated number that occures twice

I am using the coding puzzels of https://adventofcode.com for improving my F# skills. Problem: Day 1 Part 2: Starting with frequency 0, a list of numbers should be added successive generating new ...
8
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2answers
263 views

Conway's Game of Life F#

I am a C# developer learning F#. Would appreciate any suggestions on how this code can be improved. Main points I am interested in: Functional style of the code, absense of imperative style(C#) ...
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0answers
62 views

Blockchain implementation in F#: Transactions

Introduction This is Part 2 of my F# blockchain implementation. Previous parts: Block and Blockchain Code This time I am tackling transactions. The code is based on a JavaScript blockchain ...
2
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1answer
39 views

Connect elements of a list to elements of an other list using a two-dim array

Story: I build a kind of labyrinth. This labyrinth is divided in seven steps. You start with the first, then second, and so on to the seventh. You cannot go back to a previous step. Each step ...
5
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0answers
203 views

Creation of matrix with specific attempts at the end

What I want to do is build a Slay-the-Spire-like Map. As you can see in the following image, the map is splitted in ISteps and ...
5
votes
2answers
95 views

Encoding and decoding log entries in a Lossy Binary Format

One of the projects I'm working on requires logging a huge amount of information (basically, every function call). The problem is obviously that logging a lot of information has a few side-effects, ...
6
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1answer
278 views

Blockchain implementation in F#: Block and Blockchain

Some time ago I started writing a blockchain implementation for learning purposes. I used this article as reference. Originally I wrote the code in C# but recently I have rewritten everything to F#. ...
2
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0answers
104 views

Lexer function to handle the '/' character

I'm writing a toy compiler, which is in a very early stage of development. The lexer contains the following block of code: ...
2
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2answers
107 views

Sorting a list into different bags according to predicate

I've just started with F# (I'm coming from a mostly OO background) and I'm looking for feedback on the code, particularly: is this the way F# code should be written like? have I overlooked an ...
5
votes
1answer
193 views

F# Idiomatic Log4Net Wrapper

I put together a log4net wrapper that more closely resembles F#-idiomatic logging functions. The basic idea is that there's a Log module that defines a set of 8 ...
2
votes
1answer
215 views

Roslyn analyzer, converted from C# to F#

I'm learning F# and for an exercise, I took a roslyn analyzer in C# and ported it to F#. In the excerpt below the GetParameterInfo function: takes in ...
4
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1answer
99 views

Async/Await Computation Expression

When writing asynchronous code in F#, one often needs to call methods in the .NET BCL that return Task or Task<T> rather ...
10
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3answers
163 views

Generating image gauges from a value, min and max

One of the things I was recently investigating was the ability to generate "gauge" charts—that is, a chart which shows where a value stands within a range of values. As an example, if we know ...
5
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3answers
750 views

Implementing class equality/comparison in F#

I'm working on some book material on classes and interfaces in F#. My example is a latitude/longitude class: ...
4
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0answers
67 views

Hierarchy (Family Tree) Domain Model

I'm wanting to model a family tree in the F# type system. The basic requirements: A family tree is made up of family members A ...
5
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1answer
151 views

Simulating coin flips and plotting a histogram

I started playing around recently with F# and I find it quite elegant and succinct language. A common problem I like to solve in every language I start to learn is the coin flip problem, with the ...