That workaround is fragile for me:
When I put everything into one file, the "fromList/toList" rule fires.
However, when I put the test1 and main definitions into a separate file,
the "fromList/toList" rule no longer fires.
The reason for that seems to be that " fromList' = fromList " is rewritten
to " fromList' = fromList' ", and then the strictness/demand analysis flags
it up as always bottoming.
Then in the file where we write `test1 x = fromList (toList x)`, it gets
rewritten to `test1 x = fromList' (toList x)`, after which (because of the
always bottoming) it gets rewritten to `test1 _ = case fromList' of {}`On Sat, 7 Mar 2020 at 02:56, Dr. ÉRDI Gergő <ge...@erdi.hu> wrote: > As a workaround, can you try this? > https://stackoverflow.com/a/32133083/477476 > > On Fri, Mar 6, 2020, 23:23 Christiaan Baaij <christiaan.ba...@gmail.com> > wrote: > >> Hello, >> >> The other day I was experimenting with RULES and got this warning: >> >> src/Clash/Sized/Vector.hs:2159:11: warning: [-Winline-rule-shadowing] >> Rule "map Pack" may never fire >> because rule "Class op pack" for ‘pack’ might fire first >> Probable fix: add phase [n] or [~n] to the competing rule >> | >> 2159 | {-# RULES "map Pack" map pack = id #-} >> >> The warning seems to suggests two things: >> 1. "Class op" -> "dictionary projection" are implemented as rewrite rules >> and executed the same way as other user-defined RULES >> 2. These rules run first, and you cannot run anything before them >> >> Now my question is, is 1. actually true? or is that warning just a >> (white) lie? >> If 1. is actually true, would there be any objections to adding a "-1" >> phase: where RULES specified to start from phase "-1" onward fire before >> any of the Class op rules. >> I'm quite willing to implement the above if A) Class op rules are >> actually implemented as builtin RULES; B) there a no objections to this >> "-1" phase. >> >> Thanks, >> Christiaan >> >> _______________________________________________ >> ghc-devs mailing list >> ghc-devs@haskell.org >> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >> >
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