[Haskell-cafe] GHC Extension Proposal: ArgumentBlock

Manuel Gómez targen at gmail.com
Tue Sep 8 04:57:52 UTC 2015

On 09/08/2015 03:08 AM, Dan Burton wrote:
> You can even write in the old style if you have the extension turned on. It
> doesn't disable the old way of doing things. It just allows a new way. It's
> entirely backwards compatible with working code when turned on, is it not?

On Mon, Sep 7, 2015 at 11:32 PM, Bardur Arantsson <spam at scientician.net> wrote:
> Except now there are two "dialects" everybody has to read/understand.
> That's not progress IMO. (Considering that it's so little gain. I really
> don't understand the hatred of $ that some people seem to have.)

Every library published on Hackage could be said to create a new
dialect of Haskell for some specific purpose.  Operator-heavy,
multipurpose libraries such as lens could also be said to introduce
new dialects.  Yes, they all parse under the same grammar, but if you
don’t know the fixity of some operator, it might as well be some
strange unknown syntax — let alone not knowing what it actually does.

We’re so used to understanding complex semantics and diverse,
sometimes even obtuse styles of expression (pointfree, anyone?).
Surely the mental effort of parsing a lambda or a do-block in a new,
previously invalid syntax is a trivial matter for programmers
accustomed to running type checking algorithms in our heads.

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