ResizeArray

ResizeArray is an F# extension and module library for ResizeArray<'T> ( = Collection.Generic.List<'T>)

It also works in JS and TS with Fable.

This library was designed for use with F# scripting. Functions and methods never return null. Only functions starting with try... will return an F# Option. Otherwise when a function fails on invalid input it will throw a descriptive exception.

I was always annoyed that an IndexOutOfRangeException does not include the actual index that was out of bounds nor the actual size of the array. This library fixes that in resizeArray.Get, resizeArray.Set, resizeArray.Slice and other item access functions.

It Includes:

• A ResizeArray module that has a corresponding functions for all functions in the Array module from FSharp.Core. Including those for parallel computing.

• A Computational Expressions resizeArray that can be used like existing ones for seq.

• Support for F# slicing operator and indexing from the end. e.g: items.[ 1 .. ^1]

• Extension members on ResizeArray like .Get .Set .First .Last .SecondLast and more. With nicer IndexOutOfRangeExceptions that include the bad index and the actual size.

• All Tests from the from FSharp.Core's Array module ported and adapted to run in both javascript and dotnet.

See also https://github.com/goswinr/ArrayT/ for a similar library for array<'T>.

Usage

Just open the namespace

open ResizeArray

this namespace contains:

• a module also called ResizeArray
• a Computational Expressions called resizeArray
• this will also auto open the extension members on ResizeArray<'T>

then you can do:

let evenNumbers =
    resizeArray {  // a Computational Expressions like seq
        for i = 0 t 99 do
            if i % 2 = 0 then
                i
    }

let oddNumbers = evenNumbers |> ResizeArray.map (fun x -> x + 1) // ResizeArray module

let hundred = oddNumbers.Last // Extension member to access the last item in list

Why ?

Yes, F# Arrays and (linked) Lists can do these kind of operations on collections too. But ResizeArray (being mutable) still offers the best performance for collections that expand or shrink and need random access.

In fact FSharp.Core uses a very similar module internally

Full API Documentation

goswinr.github.io/ResizeArray

Tests

All Tests run in both javascript and dotnet. Successful Fable compilation to typescript is verified too. Go to the tests folder:

cd Tests

For testing with .NET using Expecto:

dotnet run

for JS testing with Fable.Mocha and TS verification:

npm test

License

MIT

Changelog

see CHANGELOG.md