(#) is a legal operator today and is used in a number of libraries. On Sun, Jun 30, 2013 at 11:38 PM, <amin...@gmail.com> wrote:
> As long as we're bikeshedding... > > Possibly '#' is unused syntax -- Erlang uses it for its records too, so we > wouldn't be pulling it out of thin air. E.g. "person#firstName" > > Tom > > > El Jun 30, 2013, a las 22:59, AntC <anthony_clay...@clear.net.nz> > escribió: > > >> Carter Schonwald <carter.schonwald <at> gmail.com> writes: > >> > >> indeed, this relates / augments record puns syntax already in > > GHC http://www.haskell.org/ghc/docs/latest/html/users_guide/syntax- > > extns.html#record-puns. > > > > Uh-oh. That documentation gives an example, and it exactly explains the > > weird type-level error I got when I tried to use the proposed syntax > > myself: > > > > Note that: > > > > * Record punning can also be used in an expression, writing, for > > example, > > > > let a = 1 in C {a} -- !!! > > > > instead of > > > > let a = 1 in C {a = a} > > > > The expansion is purely syntactic, so the expanded right-hand side > > expression refers to the nearest enclosing variable that is spelled the > > same as the field name. > > > > IOW the proposal _does_ conflict with existing syntax. (And I guess I can > > see a use for the example. Note that outside of that let binding, `a` > > would be a field selector function generated from the data decl in which > > field `a` appears -- that's the weirdity I got.) > > > > I suppose the existing syntax has a data constructor in front of the > > braces, whereas the proposal wants a term. But of course a data > > constructor is a term. > > > > So the proposal would be a breaking change. Rats! Is anybody using that > > feature? > > > >> > >> On Sun, Jun 30, 2013 at 2:59 AM, Judah Jacobson <judah.jacobson <at> > > gmail.com> wrote: > >> > >> Unlike dot notation, this is unambiguous and doesn't conflict with any > > existing syntax (AFAIK). ... > > > > > > _______________________________________________ > > Glasgow-haskell-users mailing list > > Glasgow-haskell-users@haskell.org > > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users > > _______________________________________________ > Glasgow-haskell-users mailing list > Glasgow-haskell-users@haskell.org > http://www.haskell.org/mailman/listinfo/glasgow-haskell-users >
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