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agrafix / superrecord

Haskell: Supercharged anonymous records
BSD 3-Clause "New" or "Revised" License
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Create records from tuples #20

Open habbler opened 6 years ago

habbler commented 6 years ago

I see that newest version of vinyl supports creating records from tuples. Maybe supporting this in superrecord would help with the problem of slow compile times? (I tried superrecord out, found it quite good, but decided not to live with the longer compile times). i.e. for a 7-tuple we would know in advance we are creating a record with 7 fields.

Going in the other direction would be nice as will. A function that maps from a tuple of field labels to a tuple of values. Would make reading multiple fields more concise.

agrafix commented 6 years ago

The problem with this is that we would need to manually write one instance for each tuple size since there's no abstraction over all tuple sizes. Maybe we can get away with CPP macros?

habbler commented 6 years ago

I would suggest generating the tuple instances. What I don't know is whether this could be used to help improve the compile times.

habbler commented 6 years ago

I suspect the compile time performance is due to https://ghc.haskell.org/trac/ghc/ticket/8095 I guess a fix from GHC will be necessary.

neongreen commented 4 years ago

This is done in jrec: https://github.com/juspay/jrec/blob/master/src/JRec/Tuple.hs

The tuple is generated with a script in the bin/ folder. The same script can be adapted for superrecord.

TH is also an option.

I think it brings record creation times from O(n^2) to O(n), but I have not benchmarked it.