feat: add findLastIndex method to array/fixed-endian-factory

[aayush0325]

Resolves #3144

Description

What is the purpose of this pull request?

This pull request:

• adds findLastIndex method to array/fixed-endian-factory
• adds relevant tests and benchmarks
• updates README.md with appropriate documentation.

Related Issues

Does this pull request have any related issues?

This pull request:

• resolves [RFC]: add findLastIndex method to array/fixed-endian-factory #3144

Questions

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No.

Other

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No.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
array/fixed-endian-factory	$\color{red}1163/1414$ $\color{green}+82.25\%$	$\color{red}150/162$ $\color{green}+92.59\%$	$\color{red}23/33$ $\color{green}+69.70\%$	$\color{red}1163/1414$ $\color{green}+82.25\%$

The above coverage report was generated for the changes in this PR.

[aayush0325]

kindly give this a review @kgryte!

[aayush0325]

@Planeshifter I've resolved the merge conflicts in this branch

[aayush0325]

this branch should be free of any indentation errors which were made while resolving merge conflicts now.

[kgryte]

This should always evaluate to false. E.g., value < 0.0. Otherwise, the benchmark is effectively O(1), which is not what we want.

[kgryte]

Suggested change

	* @name findLastIndex
	* @private
	* @name findLastIndex

[kgryte]

Suggested change

	var len;
	var i;
	if ( !isTypedArray( this ) ) {
	throw new TypeError( format( 'invalid invocation. `this` is not %s %s.', CHAR2ARTICLE[ dtype[0] ], CTOR_NAME ) );
	}
	if ( !isFunction( predicate ) ) {
	throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', predicate ) );
	}
	buf = this._buffer;
	len = this._length;
	for ( i = len - 1; i >= 0; i-- ) {
	var i;
	if ( !isTypedArray( this ) ) {
	throw new TypeError( format( 'invalid invocation. `this` is not %s %s.', CHAR2ARTICLE[ dtype[0] ], CTOR_NAME ) );
	}
	if ( !isFunction( predicate ) ) {
	throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', predicate ) );
	}
	buf = this._buffer;
	for ( i = this._length - 1; i >= 0; i-- ) {

The local variable is not necessary in this case, as we are only accessing _length once.

[kgryte]

@aayush0325 Thanks for working on this. Left a few comments. Once resolved, this should be ready for merge, provided that the merge conflicts are resolved.