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Author gvanrossum
Recipients Inyeol.Lee, Jim Fasarakis-Hilliard, belopolsky, benjamin.peterson, danielsh, emptysquare, erickt, esc24, georg.brandl, glyph, gvanrossum, ncoghlan, rhettinger, serhiy.storchaka, yselivanov
Date 2017-11-26.06:22:42
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On Nov 25, 2017 18:01, "Nick Coghlan" <> wrote:

> Nick Coghlan <> added the comment:
> Serhiy's PR now implements the "Prohibit yield & yield from in generator
> expressions and comprehensions" approach discussed on python-dev (currently
> as a hard SyntaxError, but it could be amended to be a warning instead
> without too much difficulty).
> The PR does highlight an interesting subtlety though: the easiest way to
> implement this still allows yield expressions in the outermost iterator,
> since that gets compiled in a different scope from the rest of the
> comprehension body (it's evaluated eagerly and passed in to the implicit
> nested function).
> I'm thinking we probably don't want to expose that detail to end users,
> and will instead want to include a second check that prohibits yield
> expressions in the outermost iterator as well. However, I'm not entirely
> sure how we could implement such a check, short of adding a new "yield
> expression prohibited" counter in the AST generation and/or symbol analysis
> pass.
> ----------
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Date User Action Args
2017-11-26 06:22:42gvanrossumsetrecipients: + gvanrossum, georg.brandl, rhettinger, ncoghlan, belopolsky, benjamin.peterson, erickt, glyph, Inyeol.Lee, serhiy.storchaka, yselivanov, esc24, danielsh, emptysquare, Jim Fasarakis-Hilliard
2017-11-26 06:22:42gvanrossumlinkissue10544 messages
2017-11-26 06:22:42gvanrossumcreate