(C) 2020 Kriss Blank under the https://opensource.org/licenses/MIT

local wutf = require("wetgenes.txt.utf")

helper functions to help manage a string as a stream of utf8 tokens.

string = wutf.char(number)

convert a single unicode value to a utf8 string of 1-4 bytes

string:gmatch(wutf.charpattern)

lua pattern to match each utf8 character in a string

string = wutf.chars(number,number,...)
string = wutf.chars({number,number,...})

convert one or more unicode values into a utf8 string

unicode = wutf.ncode(string,index)

get the utf8 value at the given code index.

Note that this is slower than wutf.code as we must search the string to find the byte index of the code.

unicode = wutf.map_latin0_to_unicode[latin0] or latin0

latin0 = wutf.map_unicode_to_latin0[unicode] or unicode

I prefer the coverage of latin0 (ISO/IEC 8859-15) for font layout as it is just a few small differences for western european languages to get most needed glyphs into the first 256 codes.

size = wutf.size(string,index)

get the size in bytes of the utf8 value at the given byte index.

size = wutf.size(string)

get the size in bytes of the utf8 value at the start of this string

The return value will be 1-4 as 4 is the biggest utf8 code size.

unicode = wutf.code(string,index)

get the utf8 value at the given byte index.

unicode = wutf.code(string)

get the utf8 value at the start of this string