Re: Using guile as an extension language for GNU make

[Hans Aberg]

On 21 Sep 2011, at 04:42, Mark H Weaver wrote:

>> And finally, currently I have all unknown types expanding to the empty
>> string but now I'm thinking it would be better to start out more
>> restrictive and throw errors.  This would ensure that people write their
>> Guile scripts correctly (giving valid return values) from the start, and
>> would let me, in the future, expand the supported types without breaking
>> anything.
> 
> I agree wholeheartedly.  If you are too permissive, it may cause
> programming errors to go unnoticed.  It's better to limit the automatic
> conversions to common cases that are clearly useful.  The other cases
> can be handled easily from Scheme.
> 
> As for the suggestion to look at the pretty-printing library: I don't
> see why that would be useful.  The purpose of that library is primarily
> to intelligently choose where to insert newlines in nested list
> structure, so that lines don't grow too long for the terminal display,
> and to add indentation as would be found in typical Scheme source code.
> It seems to me that these functions are undesirable for this purpose.

What I had in my mind is a more general "pretty-printing" object, which can 
override normal printing. For each object, one should be able define new 
printing. Perhaps Guile would need to have some kind of extension to achieve 
that.

Hans