Additions to the standard library

[TimWhiting]

No description provided.

[Copilot]

Pull request overview

This PR adds a comprehensive set of utility functions to the Koka standard library for both vectors and lists, enhancing functional programming capabilities.

Key Changes:

• Added vector operations including folding (foldl, foldr), zipping (zip, zip-with, zip-with-indexed), and collection manipulation (take, drop, slice, reverse, append)
• Introduced predicate/equality-based overloads for list functions using namespace prefixes (pred/ and eq/)
• Added missing comparison operators for ssize_t type (==, !=, >)

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
lib/std/core/vector.kk	Adds functional programming utilities (fold, zip, map-indexed), collection manipulation functions (take, drop, slice, reverse, append), equality operators, and additional ssize_t comparison operators
lib/std/core/list.kk	Refactors existing functions with namespace prefixes (pred/, eq/) and adds equality-based variants (contains, eq/remove, eq/lookup, eq/index-of) with improved parameter destructuring

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[Copilot]

The return type is inconsistent with pred/index-of which returns int (with -1 for not found). This function returns maybe<int>, which creates an inconsistency in the API. Consider either returning int with -1 for consistency, or updating both functions to use maybe<int>.

Suggested change

	pub fun eq/index-of( xs : list<a>, value : a, ?(==) : (a,a) -> e bool ) : e maybe<int>
	fun recur( ys, idx )
	match ys
	Cons(y,yy) -> if y==value then Just(idx) else recur(yy,idx+1)
	Nil -> Nothing
	pub fun eq/index-of( xs : list<a>, value : a, ?(==) : (a,a) -> e bool ) : e int
	fun recur( ys, idx )
	match ys
	Cons(y,yy) -> if y==value then idx else recur(yy,idx+1)
	Nil -> -1

[Copilot]

The documentation comment "Append two vectors" is duplicated from the append function above (line 274). This should describe that it's an operator alias for append or reference the append function.

Suggested change

	// Append two vectors
	// Operator alias for `append`: append two vectors.