[ghc-steering-committee] #493: SPECIALISE with expressions, rec: accept

[Adam Gundry]

Dear all,

Richard and Simon propose to generalise SPECIALISE pragmas to allow 
expressions, not just type signatures:

https://github.com/ghc-proposals/ghc-proposals/pull/493
https://github.com/goldfirere/ghc-proposals/blob/specialise/proposals/0000-specialise-expressions.rst

This does not add anything fundamentally new, because such SPECIALISE 
pragmas can be translated using the existing RULES machinery, but it 
does make several idioms substantially more convenient:

  * Using type applications in a SPECIALISE pragma to avoid repetition

  * Manual call-pattern specialisation

  * Loop unrolling

Thus I propose we accept this proposal.

Cheers,

Adam


-- 
Adam Gundry, Haskell Consultant
Well-Typed LLP, https://www.well-typed.com/

Registered in England & Wales, OC335890
27 Old Gloucester Street, London WC1N 3AX, England