Extend performance group with Text/ByteString strictness hints#1693
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mgajda wants to merge 1 commit intondmitchell:masterfrom
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Extend performance group with Text/ByteString strictness hints#1693mgajda wants to merge 1 commit intondmitchell:masterfrom
mgajda wants to merge 1 commit intondmitchell:masterfrom
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Adds same-module, semantics-preserving strict-variant rewrites for Data.Text / Data.ByteString and their Lazy and Char8 variants in the opt-in performance group. All patterns use fully-qualified module names so they only fire on the exact import users actually wrote. - Data.Text.foldl / Data.Text.Lazy.foldl -> foldl' (strict left fold) - Data.ByteString.foldl / Data.ByteString.Lazy.foldl -> foldl' - Data.ByteString.Char8.foldl / Data.ByteString.Lazy.Char8.foldl -> foldl' - Data.Text.concat (map f xs) -> Data.Text.concatMap f xs - Data.Text.Lazy.concat (map f xs) -> Data.Text.Lazy.concatMap f xs Not included: Data.ByteString.concat . map fusion. Data.ByteString's concatMap has signature (Word8 -> ByteString) -> ByteString -> ByteString, so it is NOT the fusion of concat . map over [ByteString]. Nor are any lazy-type-to-strict-type rewrites (e.g. Data.Text.Lazy.pack -> Data.Text.pack) included; those change semantics and would silently break code that needs lazy I/O.
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Part of a set of independent PRs adding rules to the opt-in
performancegroup (disabled by default; enabled via--with-group=performanceor per-project config). Each PR in the settargets a separate rule family and can be reviewed/merged
independently.
This one covers
Data.Text/Data.ByteStringstrict-variant rewrites.Rules added
All matches use fully-qualified module names so they fire only on the
exact lazy imports users wrote (never on Prelude/Foldable
foldl).Data.Text.foldl/Data.Text.Lazy.foldl->foldl'Data.ByteString.foldl/Data.ByteString.Lazy.foldl->foldl'Data.ByteString.Char8.foldl/Data.ByteString.Lazy.Char8.foldl->foldl'Data.Text.concat (map f xs)->Data.Text.concatMap f xsData.Text.Lazy.concat (map f xs)->Data.Text.Lazy.concatMap f xsData.ByteString.concatMaphas a different type(
(Word8 -> ByteString) -> ByteString -> ByteString) so theconcat . mapfusion rule is deliberately NOT applied there.