ArrayT

ArrayT is an F# extension and module library for Array<'T>

It also works in Javascript and Typescript with Fable.

Motivation

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 array.Get, array.Set, array.Slice and other item access functions.

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.

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

It Includes:

• An Array module that has a additional functions to the Array module from FSharp.Core.
  See docs

• Extension members on Array like
  .Get(idx) .Set(idx,item) .First .Last .SecondLast xs.DebugIdx.[i] and more..
  With nicer IndexOutOfRangeExceptions that include the bad index and the actual size.
  See docs

Usage

Just open the namespace

open ArrayT

this namespace contains:

• a module also called Array. It will add additional functions to the Array module from FSharp.Core.

• this will also auto open the extension members on Array<'T>

Example

#r "nuget: ArrayT"
open ArrayT

let xs = [| 0 .. 88 |]

xs.Get(99)

throws

System.IndexOutOfRangeException: Array.Get: Can't get index 99 from:
array<Int32> with 89 items:
  0: 0
  1: 1
  2: 2
  3: 3
  4: 4
  ...
  88: 88

instead of the usual

System.IndexOutOfRangeException: Index was outside the bounds of the array.

If you want to use the index notation xs.[i] instead of the Get method you can use the DebugIdx member

xs.DebugIdx.[i]

Full API Documentation

goswinr.github.io/ArrayT

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