Add functions to the Map module and reformat

[lukaszcz]

• Closes Add merge function for Map #132
• Adds the intersection/difference/union functions to the Map module.
• Reformats the standard library for the recent changes in the Juvix formatter.

[paulcadman]

Perhaps @heueristik could review the new API to see if meets what is needed for applications?

juvix-stdlib/Stdlib/Data/Map.juvix

Lines 240 to 290 in 9f3226f

	--- 𝒪(n log n). Intersection of two maps. Returns data in the first map for the
	--- keys existing in both maps.
	{-# inline: true #-}
	intersection
	{Key Value} {{Ord Key}} (map1 map2 : Map Key Value) : Map Key Value :=
	case map1, map2 of mkMap s1, mkMap s2 := mkMap (Set.intersection s1 s2);
	--- 𝒪(n log n). Return elements of `map1` with keys not existing in `map2`.
	{-# inline: true #-}
	difference
	{Key Value} {{Ord Key}} (map1 map2 : Map Key Value) : Map Key Value :=
	case map1, map2 of mkMap s1, mkMap s2 := mkMap (Set.difference s1 s2);
	--- 𝒪(n log n). Returns a ;Map; containing the elements that are in `map1` or
	--- `map2`. This is a left-biased union of `map1` and `map2` which prefers
	--- `map1` when duplicate keys are encountered.
	{-# inline: true #-}
	unionLeft {Key Value} {{Ord Key}} (map1 map2 : Map Key Value) : Map Key Value :=
	case map1, map2 of mkMap s1, mkMap s2 := mkMap (Set.unionLeft s1 s2);
	--- 𝒪(n log n). Returns a ;Map; containing the elements that are in `map1` or `map2`.
	{-# inline: true #-}
	union {Key Value} {{Ord Key}} (map1 map2 : Map Key Value) : Map Key Value :=
	case map1, map2 of mkMap s1, mkMap s2 := mkMap (Set.union s1 s2);
	{-# specialize: [1, 2] #-}
	unions
	{Key Value Container}
	{{Ord Key}}
	{{Foldable Container (Map Key Value)}}
	(maps : Container)
	: Map Key Value :=
	for (acc := empty) (map in maps) {
	union acc map
	};
	--- O(n log n). If `map1` and `map2` are disjoint (have no common keys), then
	--- returns `ok map` where `map` is the union of `map1` and `map2`. If `map1`
	--- and `map2` are not disjoint, then returns `error k` where `k` is a common
	--- key.
	{-# inline: true #-}
	disjointUnion
	{Key Value}
	{{Ord Key}}
	(map1 map2 : Map Key Value)
	: Result Key (Map Key Value) :=
	case map1, map2 of
	mkMap s1, mkMap s2 :=
	case Set.disjointUnion s1 s2 of
	| error x := error (key x)
	| ok s := ok (mkMap s);

[paulcadman]

I'll merge this now, @heueristik can let us know if something else is required.