[Haskell] Re: Proposal: Allow "\=" for field update in record update syntax

Andre Pang ozone at algorithm.com.au
Sat Feb 19 06:33:00 EST 2005


On 19/02/2005, at 5:20 AM, Keean Schupke wrote:

> Yes, your idea is much nicer... I was just suggesting TH as a way to 
> implement custom  syntax... It would be nice if come sort of standard 
> existed for template-haskell so that other compilers/interpreters 
> could adopt it. A portable template would be a cool thing.

The $(...) syntax that you need at the splice site greatly diminishes 
the potential for Template Haskell to be used as syntax, unfortunately. 
  The interesting (or frustrating?) thing is that Template Haskell 
implements the majority of the hard work needed for a proper hygienic 
macro system, but unfortunately doesn't go quite the extra mile to 
enable you to actually define new syntax.  I suspect all you'd need is 
a way to annotate the function you wanted to use as a macro, so that 
the compiler knows that the function should always be spliced in, 
rather than be explicitly spliced in at the call site.  (People who 
know better, shoot me down if I'm wrong ...)

I'd actually go so far blame the lack of macro support in TH on the 
Haskell community as a whole, since the general consensus I get from 
e.g. the mailing lists is that "syntactic sugar is bad".


-- 
% Andre Pang : trust.in.love.to.save  <http://www.algorithm.com.au/>


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