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|
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE OverloadedLabels #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# OPTIONS_GHC -freduction-depth=0 #-}
{- Notes on LargeRecord
~~~~~~~~~~~~~~~~~~~~~~~
I noticed that in GHC of July 2022, when compiling this
module I got lots of "SPEC" rules
SuperRecord.$fRecCopy:ltsrts_$crecCopyInto @"f2"
@'["f1" := Int, "f2" := Int, "f3" := Int,
"f4" := Int]
@Int
@'["f2" := Int, "f3" := Int, "f4" := Int]
@'["f3" := Int, "f4" := Int]
$d(%,,%)_X1 $d(%,,%)1_X2 $dRecCopy_X3
SuperRecord.$fRecCopy:ltsrts_$crecCopyInto @"f3"
@'["f1" := Int, "f2" := Int, "f3" := Int,
"f4" := Int]
@Int
@'["f2" := Int, "f3" := Int, "f4" := Int]
@'["f4" := Int]
$d(%,,%)_X1 $d(%,,%)1_s6yK $dRecCopy_X2
SuperRecord.$fRecCopy:ltsrts_$crecCopyInto @"f3"
@'["f2" := Int, "f3" := Int, "f4" := Int]
@Int
@'["f3" := Int, "f4" := Int]
@'["f4" := Int]
$d(%,,%)_s6yr $d(%,,%)1_X1 $dRecCopy_X2
SuperRecord.$fRecCopy:ltsrts_$crecCopyInto @"f4"
@(SortInsert'
(GHC.TypeLits.Internal.CmpSymbol "f3" "f4")
("f3" := Int)
("f4" := Int)
'[])
@Int
@'["f4" := Int]
@'[]
$d(%,,%)_X1 $d(%,,%)1_X2 $dRecCopy_s6yb
(This was with BigFieldList having only four elements.)
The relevant function SuperRecord.$fRecCopy:ltsrts_$crecCopyInto is
only a wrapper that we were specialising -- little or no benefit. We
don't want to specialise wrappers! -}
module DCo_Record where
import SuperRecord
type BigFieldList =
'[ "f1" := Int
, "f2" := Int
, "f3" := Int
, "f4" := Int
, "f5" := Int
, "f6" := Int
, "f7" := Int
, "f8" := Int
, "f9" := Int
, "f10" := Int
, "f11" := Int
, "f12" := Int
, "f13" := Int
, "f14" := Int
, "f15" := Int
]
bigRec :: Record BigFieldList
bigRec =
#f1 := 1
& #f2 := 2
& #f3 := 3
& #f4 := 4
& #f5 := 5
& #f6 := 6
& #f7 := 7
& #f8 := 8
& #f9 := 9
& #f10 := 10
& #f11 := 11
& #f12 := 12
& #f13 := 13
& #f14 := 14
& #f15 := 15
& rnil
main :: IO ()
main = print "ok"
|
