On 24 February 2014 10:52, Nicolas Cellier
<nicolas.cellier.aka.nice at gmail.com> wrote:
> Though being reserved for return statements, the upArrow ^ could perfectly
> be accepted as a character composing a binary selector, like the verticalBar
> | already is.
> Indeed there is no ambiguity, since the return ^ is always prefixed, while a
> binary message never is...
> (well, except in the method source, but method source must begin with
> selector, it cannot begin with a return statement, so no ambinguity there
> neither...).
>
> I don't plan to use or add such selector in core Squeak/Pharo, but I think
> that it is important to allow a variety of selectors : it allows the most
> simple DSL : one using Smalltalk syntax (no need to define a new syntax, a
> new parser, etc...).
> If we did it for |, I don't see why we shouldn't for ^.
> Note that we recently also extended usage of - at any place in binary
> selectors (it was restricted to first position previously), though no core
> message is concerned so far.
>
> The main objection could be that a missing period before a return statement
> won't be reported, but interpreted as a message send... like in:
>     x := a+b
>     ^x
>
> But I don't think it's really a feature stopper.
>
> It's very easy to modify the old Compiler and shouldn't be that hard in Opal
> too.
> I'll try and push a prototype in Squeak inbox this evening.
>
> What do you think?

I think that I should read _all_ my mail before repyling. I mildly in
favour of allowing ^ as a binary selector. It would be nice if we
could automatically infer the impact of seemingly minor grammatical
changes like this, and sniff out newly introduced ambiguities and
such.

frank