ListEqualsEmptyListAnalyzer

Problem

It is less performant to check if a list is empty by using the = operator.

let a = [ 1; 2; 3 ]
// Analyzer will trigger
let b = [] = a

Fix

let b = List.isEmpty a // will check if there is no tail which is faster than the equality check.

Code fix

This analyzer has a code fix for Ionide:

Code fix for ListEqualsEmptyList

val a: int list

val b: bool

Multiple items
module List from Microsoft.FSharp.Collections

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type List<'T> = | op_Nil | op_ColonColon of Head: 'T * Tail: 'T list interface IReadOnlyList<'T> interface IReadOnlyCollection<'T> interface IEnumerable interface IEnumerable<'T> member GetReverseIndex: rank: int * offset: int -> int member GetSlice: startIndex: int option * endIndex: int option -> 'T list static member Cons: head: 'T * tail: 'T list -> 'T list member Head: 'T member IsEmpty: bool member Item: index: int -> 'T with get ...

val isEmpty: list: 'T list -> bool