Re: Programming Lout Backends

On Tue, Dec 16, 2008 at 07:07:35PM +0100, Christoph Angerer wrote:
> 
> My idea would have been, to use lout as the "lingua franca" and  
> provide different backends in lout to generate the formats directly  
> instead of trying to convert postscript files into mobipocket files
> 
> My question is now: does anybody think this is feasible? How difficult  
> is it (in practice) to write another lout backend? As I said, the  
> input documents are?at least for now?rather simple texts with sections  
> and subsections and maybe sometimes boldface font or a quote.
> 
> In the lout source code, backends look pretty well modularized; I am  
> thinking of the typedef struct back_end_rec in externs.h that seems to  
> provide some plugin functionality. So is it as simple as providing  
> implementations of those 26 functions to produce a file in a  
> completely new format? Or are there some caveats or am i missing  
> something? (Since the PDF backend is kinda discontinued it makes me  
> think that this might be harder than it looks...)

I don't think Lout is well suited to the job of being a universal
document markup language.  I can't think of any language that is
well suited to that task, except Nonpareil, which does not exist yet.

There are a lot of issues hiding behind the 26 backend functions.

My suggestion would be to make a design that allowed multiple formats
and plugins that convert those formats to other formats.  In the end
I think you want to be displaying PDF, because it can display all
kinds of fun things, it is a moderately reliable standard, and there
are converters from virtually every format to PDF.  But of course
you can't store documents in PDF format, because they are already
laid out in a fixed format.

Jeff