On 07/01/09 00:39, Matt Wozniski wrote:
> On Tue, Jan 6, 2009 at 6:10 PM, Tony Mechelynck wrote:
>> On 06/01/09 12:31, anhnmncb wrote:
>>> Hi, list, as title, if so, why can't many functions
>>> still handle correctly with unicode? For example the func:
>>>
>>> getline('.')[col('.')-1]
>>>
>>> Can't return a charactor outside the range of ascii.
>>>
>> because string[index] returns a byte value, not a character value: see
>> ":help expr8".
>
> *Nod*
>
>> If the character at the cursor is> U+007F, you'll get
>> the first byte (in the range 0xC0-0xFD, or in practice in the range
>> 0xC0-0xF4) of its UTF-8 representation.
>
> No, you could get some byte of some entirely different character. Ie,
> on a line with two 2-byte characters, getline('.')[col('.')-1] on the
> second character would return the 2nd byte of the first character.
col() gives a one-based byte ordinal. [] takes a zero-based argument. I
stand by what I said.
>
>> The _character_ at the cursor is obtained as follows:
>> let i0 = byteidx(getline('.'), virtcol('.') - 1)
>> let i1 = byteidx(getline('.'), virtcol('.'))
>> let character = strpart(getline('.'), i0, i1 - 10)
>
> Using virtcol() there seems broken... what if you're in the middle of
> a tab, for example, with virtualedit=all?
>
> :echo join(split("áéíóú", '\zs')[1:3], '')
OK, I didn't think of virtual editing, nor even, it seems, of
multi-column characters such as tabs and fullwidth CJK. However, [1:3]
wouldn't work because the idea is that we're in a script, we don't know
that we're in the 1st, 2nd or 3rd column, just that we want "whatever is
at the cursor". I might do it with
function CursorChar()
normal yl
return @@
endfunction
>
> is how I would do it... but, is there any real reason why indexing
> into a string *should* be byte oriented instead of character oriented,
> apart from backwards compatibility? It seems drastically less easy to
> use the thing that more people want to use more of the time; and in
> fact some of the snippets in the vim help (like the example given at
> :help expr-8) won't work on multibyte lines given the way that string
> indexing works now. It seems like a place where the cost of losing
> backwards compatibility might be outweighed by the cost of keeping
> things the way they are...
>
> ~Matt
Changing an existing construct from byte-oriented to
multibyte-character-oriented would probably break a lot of existing
scripts. I don't believe Bram would ever accept that.
Best regards,
Tony.
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