Proposal: Rename `mem.trimLeft` and `mem.trimRight` to `mem.trimStart` and `mem.trimEnd`

[sorairolake]

std.mem.trimLeft removes a set of values from the beginning of a slice, and std.mem.trimRight removes a set of values from the end of a slice.

In left-to-right scripts (most languages), these functions do exactly what their names suggest:

const s = "日本語";
std.debug.print("{}\n", .{std.mem.eql(u8, "日本", std.mem.trimRight(u8, s, "語"))}); // true

But in right-to-left scripts (such as Hebrew and Arabic), these functions do not work as their names suggest:

const s = "עִבְרִית";
std.debug.print("{}\n", .{std.mem.eql(u8, "בְרִית", std.mem.trimRight(u8, s, "עִ"))}); // false
std.debug.print("{}\n", .{std.mem.eql(u8, "עִבְרִי", std.mem.trimRight(u8, s, "ת"))}); // true

In right-to-left scripts, the end of the string is on the left, so we specify the left characters to trimRight. I think this is strange. So I think it would be better to rename mem.trimLeft to mem.trimStart, and mem.trimRight to mem.trimEnd.

[alexrp]

I feel like them being in std.mem ought to be a hint that they don't really have anything to do with strings per se.

But on the other hand, we do also have startsWith and endsWith, and there's precedent for your suggested naming in other languages. And if it also removes potential confusion, then why not?

I don't know if this needs a proposal, FWIW. I think you could just open a PR that renames the functions and adds deprecated aliases for the old spellings and we can decide whether to take it.

[Fri3dNstuff]

I feel like them being in std.mem ought to be a hint that they don't really have anything to do with strings per se.
@alexrp

Even if the functions are to be thought of as working on arrays' elements, and not texts, the naming is still an issue: not everyone thinks of sequences as ordered left-to-right, in part because native speakers of RTL languages naturally order sequences right-to-left, and partly because even when working in English we sometimes think of sequences going in other directions (e.g. a program's memory space is usually visualised vertical).

I did raise this issue on the Discord server a while back, and @andrewrk seemed to agree, though he did say it should probably be fixed as part of a larger overhaul of std function and type names