Clarify seq documentation
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Authored by psibi on Sep 11 2017, 10:10 AM.

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Summary

Improves the documentation by specifying that the first argument in
seq function is evaluated to WHNF.

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rGHC Glasgow Haskell Compiler
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psibi created this revision.Sep 11 2017, 10:10 AM
psibi updated this revision to Diff 13820.Sep 11 2017, 10:23 AM
  • Add further clarification
harendra added inline comments.
compiler/prelude/primops.txt.pp
2819

I would rephrase it like this:

The value of {\tt seq a b} is bottom if {\tt a} is bottom, and otherwise equal to {\tt b}. In other words, it evaluates the first argument {\tt a} to weak head normal form (WHNF). {\tt seq} is usually introduced to improve performance by avoiding unneeded laziness.

bgamari accepted this revision.Sep 13 2017, 11:32 AM

Thanks!

This revision is now accepted and ready to land.Sep 13 2017, 11:32 AM
bgamari retitled this revision from seq documentation: fix trac issue #14213 to Clarify seq documentation.Sep 13 2017, 11:33 AM
bgamari updated the Trac tickets for this revision.
This revision was automatically updated to reflect the committed changes.