PUBLIC
Just so this isn't prematurely all lost, I went back and looked for this
example. With the following two definitions:
subsequences :: [a] -> [[a]]
subsequences xs = [] : nonEmptySubsequences xs
nonEmptySubsequences :: [a] -> [[a]]
nonEmptySubsequences [] = []
nonEmptySubsequences (x:xs) = [x] : foldr f [] (nonEmptySubsequences xs)
where f ys r = ys : (x : ys) : r
If I save the interface, load it back and look at the unfoldings, I see that
`subsequences` has a useful unfolding:
subsequences Unf{Src=<vanilla>, TopLvl=True, Value=True,
ConLike=True, WorkFree=True, Expandable=True,
Guidance=IF_ARGS [0] 30 10}
Whereas `nonEmptySubsequenes` has a trivial one:
nonEmptySubsequences OtherCon []
The interface I save is created from the ModDetails returned by tidyProgram.
ExposeAllUnfoldings is set.
Unfortunately, I am unable to reproduce this from the command line using the
GHC executable, so before I put in the effort of making a minimal example of
using the GHC API to get this result, I would first like to know if this is
even an interesting case, or if there is some explanation for why one of these
two would have an unfolding when the other doesn't, in certain cases.
-----Original Message-----
From: ghc-devs <[email protected]> On Behalf Of Gergo Érdi
Sent: Saturday, April 2, 2022 11:31 AM
To: Simon Peyton Jones <[email protected]>
Cc: GHC Devs <[email protected]>; [email protected]
Subject: [External] Re: Avoiding `OtherCon []` unfoldings, restoring
definitions from unfoldings
I'm using Prep's output (mostly so that it's in ANF) in my full compilation
pipeline, so ideally I would save Prep'd Core in my .hi-equivalents so that I
don't have to rerun Prep on them every time I use them.
I'll get back to you with some concrete examples of `OtherCon []` vs.
meaningful unfoldings next week.
Merging with my other question about shadowing problems with `toIface*`, in
summary it seems that what I really should be doing, is compiling up to Tidy,
taking the `CoreBinding`s from there and using `toIfaceBinding` on them to save
the definitions.
This email and any attachments are confidential and may also be privileged. If
you are not the intended recipient, please delete all copies and notify the
sender immediately. You may wish to refer to the incorporation details of
Standard Chartered PLC, Standard Chartered Bank and their subsidiaries at
https: //www.sc.com/en/our-locations
Where you have a Financial Markets relationship with Standard Chartered PLC,
Standard Chartered Bank and their subsidiaries (the "Group"), information on
the regulatory standards we adhere to and how it may affect you can be found in
our Regulatory Compliance Statement at https: //www.sc.com/rcs/ and Regulatory
Compliance Disclosures at http: //www.sc.com/rcs/fm
Insofar as this communication is not sent by the Global Research team and
contains any market commentary, the market commentary has been prepared by the
sales and/or trading desk of Standard Chartered Bank or its affiliate. It is
not and does not constitute research material, independent research,
recommendation or financial advice. Any market commentary is for information
purpose only and shall not be relied on for any other purpose and is subject to
the relevant disclaimers available at https:
//www.sc.com/en/regulatory-disclosures/#market-disclaimer.
Insofar as this communication is sent by the Global Research team and contains
any research materials prepared by members of the team, the research material
is for information purpose only and shall not be relied on for any other
purpose, and is subject to the relevant disclaimers available at https:
//research.sc.com/research/api/application/static/terms-and-conditions.
Insofar as this e-mail contains the term sheet for a proposed transaction, by
responding affirmatively to this e-mail, you agree that you have understood the
terms and conditions in the attached term sheet and evaluated the merits and
risks of the transaction. We may at times also request you to sign the term
sheet to acknowledge the same.
Please visit https: //www.sc.com/en/regulatory-disclosures/dodd-frank/ for
important information with respect to derivative products.
_______________________________________________
ghc-devs mailing list
[email protected]
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
