Add IterTools PHP to Architectural section

[Smoren]

Added IterTools PHP - A library that provides functionality for working with iterable entities (similar to itertools library in Python).

[llaville]

Seems equivalent to https://github.com/nikic/iter !

[Smoren]

@llaville, thanks for feedback!

PHP iterTools is similar to iter but not equivalent because it provides a lot more functionality. Please look at the documentation in the README of the project.

Moreover, it provides fluent interface to make chain operations on iterables (Stream class):

$result = Stream::of([1, 1, 2, 2, 3, 4, 5])
    ->distinct()                 // [1, 2, 3, 4, 5]
    ->map(fn ($x) => $x**2)      // [1, 4, 9, 16, 25]
    ->filter(fn ($x) => $x < 10) // [1, 4, 9]
    ->toSum();                   // 14

[Smoren]

• iter provides 41 functions.
• IterTools PHP provides 78 methods excluding stream functionality.

Here is a comparison:

IterTools PHP	iter
Multi::chain	chain
Multi::zip	zip
Multi::zipEqual	-
Multi::zipLongest	-
-	zipKeyValue
Single::chunkwise	chunk
Single::chunkwiseOverlap	-
-	chunkWithKeys
Single::compress	-
Single::compressAssociative	-
-	drop
Single::dropWhile	dropWhile
-	enumerate, toPairs (equivalents of each other, but not equivalents of Single::pairwise)
Single::filter	filter
Single::filterTrue	-
Single::filterFalse	-
Single::filterKeys	-
Single::flatMap	flatMap
Single::flatten	flatten
-	flip
Single::groupBy	-
-	keys
Single::limit	-
Single::map	map
-	mapKeys
-	mapWithKeys
Single::pairwise	-
-	product
Single::reindex	reindex
Single::repeat	repeat
Single::reverse	-
-	recurse
Single::slice	slice
Single::string	split
-	take
Single::takeWhile	takeWhile
Infinite::count	range
Infinite::cycle	-
Infinite::repeat	-
Random::choice	-
Random::coinFlip	-
Random::number	-
Random::percentage	-
Random::rockPaperScissors	-
Math::runningAverage	-
Math::runningDifference	-
Math::runningMax	-
Math::runningMin	-
Math::runningProduct	-
Math::runningTotal	-
Set::distinct	-
Set::intersection	-
Set::intersectionCoercive	-
Set::partialIntersection	-
Set::partialIntersectionCoercive	-
Set::symmetricDifference	-
Set::symmetricDifferenceCoercive	-
Sort::asort	-
Sort::sort	-
File::readCsv	-
File::readLines	-
-	fromPairs
Transform::tee	-
Transform::toArray	toArray
Transform::toAssociativeArray	toArrayWithKeys
Transform::toIterator	toIter
Summary::allMatch	all
Summary::anyMatch	any
Summary::arePermutations	-
Summary::arePermutationsCoercive	-
Summary::exactlyN	-
-	isEmpty
-	isIterable
Stream::callForEach	apply
Summary::isPartitioned	-
Summary::isSorted	-
Summary::isReversed	-
Summary::noneMatch	-
Summary::same	-
Summary::sameCount	-
-	reductions
-	search
Reduce::toAverage	-
Reduce::toCount	count
Reduce::toFirst	-
Reduce::toFirstAndLast	-
Reduce::toLast	-
Reduce::toMax	-
Reduce::toMin	-
Reduce::toMinMax	-
Reduce::toProduct	-
Reduce::toRange	-
Reduce::toString	join
Reduce::toSum	-
Reduce::toValue	reduce
-	values

[llaville]

@Smoren thanks for compare report

[Smoren]

BTW, IterTools PHP is mentioned in PHP Annotated February 2023 by JetBrains.

[Smoren]

@ziadoz thank you for merging this PR!