Re: Convert utf8 string to iso8859-1 (Latin1)

[Christian <cn00@...>]

On 2015-02-11 20:29 Sean Conner wrote:
> It was thus said that the Great Igor Medeiros once stated:
> > Dear contributors,
> >
> > Is there a way to covert a string whose characters are encoded in utf8, to
> > a string with characters encoded in iso-8859-1, just using lua standard
> > libs? I cannot use libs with C codes.
> >
> > If there is, could you tell me how to do that or even point some site with
> > this information?
>    I don't know of any existing Lua code to do this, but the concept is
> straightforward:
>
> 	1. convert UTF-8 sequence to a Unicode codepoint
> 	   (http://en.wikipedia.org/wiki/UTF-8)
>
> 	2. Convert the Unicode codepoint
> 	(http://www.unicode.org/Public/UCD/latest/charts/CodeCharts.pdf  WARNING:
> 	LARGE PDF) to ISO-8859-1 codepoint
> 	(http://en.wikipedia.org/wiki/ISO/IEC_8859-1)
>
> 	3. Go back to step 1 if more data.
>
>    -spc (That should be enough to get you going ... )

Actually, the Latin 1 subset of unicode has the same codepoints as 
Latin1. It's just that UTF-8 is a different encoding. The following 
suffices to do the conversion with Lua 5.3:

    function utf8_to_latin1(s)
        local r = ''
        for _, c in utf8.codes(s) do
            r = r .. string.char(c)
        end
        return r
    end


HTH, Christian