On Sunday, 5 October 2014 at 08:27:58 UTC, Uranuz wrote:
I have struct StringStream that I use to go through and parse
input string. String could be of string, wstring or dstring
type. I implement function popChar that reads codeUnit from
Stream. I want to have *debug* mode of parser (via CT switch),
where I could get information about lineIndex, codeUnitIndex,
graphemeIndex. So I don't want to use *front* primitive because
it autodecodes everywhere, but I want to get info abot index of
*user perceived character* in debug mode (so decoding is needed
here).
Question is how to detect that I go from one Unicode grapheme
to another when iterating on string, wstring, dstring by code
unit? Is it simple or is it attempt to reimplement a big piece
of existing std library code?
You can use std.uni.byGrapheme to iterate by graphemes:
http://dlang.org/phobos/std_uni.html#.byGrapheme
AFAIK, graphemes are not "self synchronizing", but codepoints
are. You can pop code units until you reach the beginning of a
new codepoint. From there, you can iterate by graphemes, though
your first grapheme might be off.
