fix(IdeMenu): Use width instead of bytes/chars

[ysthakur]

Fixes #997

We were looking at number of bytes/chars to get the width of the suggestion values and base strings. This didn't work with multibyte characters. The fix is to use the Unicode width of these strings.

This is what the IDE menu looks like with suggestions containing 验 (a multibyte character)

~/reedline| he
             ╭────────────────────────────────────────────────╮
             │hello another very large option for hello wor...│
             │hello world 1                                   │
             │hello world 2                                   │
             │hello world another                             │
             │hello world reedline验                          │
             │hello world something                           │
             │hello world验验验                               │
             ╰────────────────────────────────────────────────╯

~/reedline| hello wo
                   ╭──────────────────────╮
                   │hello world 1         │
                   │hello world 2         │
                   │hello world another   │
                   │hello world reedline验│
                   │hello world something │
                   │hello world验验验     │
                   ╰──────────────────────╯

[fdncred]

I'm fine with this but I always wonder with things like this, should it be width, unicode-width, or graphemes?

[ysthakur]

@fdncred What's the difference between width and unicode-width? I've only been using .width() from the unicode_width crate, which I assume gives the latter.

For string length, I think the only choices that make sense are bytes, chars, and width. If we care about how wide a string looks visually (in other words, how many columns a string will occupy in the terminal), it must be .width(), because a single grapheme can take up multiple columns.

I don't think number of graphemes is ever useful for anything. Graphemes are good when you want to do something with the individual graphemes rather than the whole string (okay that sounds a little silly and obvious but hopefully you get what I mean)

[fdncred]

Ok. Sounds good.

[ysthakur]

Just to be sure, are you okay with this being merged? (there aren't a lot of people around to approve anyway)

[fdncred]

@ysthakur yes, i just wanted to make sure that width() was at least unicode-width's width and not something else. Your explanation of graphemes seems logical to me.