Re: [q-lang-users] The implicit operator in Q

[John C. <co...@cc...>]

Albert Graef scripsit:

> 1. forbid a variable as the head element of the toplevel expression on 
> the lhs of an equation

I think it's against the spirit of Q to forbid something for no particular
reason, just because something that seems equivalent is forbidden
for good reason.  So I'd say no.

> 2. never reduce a function application with a "const" in the head, even 
> if there's a rule which allows this

This would be very surprising.  Rules should either work or provoke
an error.

> 3. forget about "const" and allow rules with constants in the head (but 
> this means that an equation like "0=1;" would be valid Q again)

That makes hash of the idea of constructors, which is a very important
one.  0 is just as much a constructor as bin_stream.

> 4. be happy that Q still leaves some dirty tricks to be discovered by 
> the master Q programmer ;-)

Indeed, though I think this particular trick could now be documented
in the manual.

> Note that this invisible operator is in fact just function application. 
> Since expressions in Q are not subject to any typing constraints, 
> nothing keeps you from writing something like "0 1" which applies the 
> "function" 0 to the "argument" 1.

I discovered this when playing with my Chicken egg; at that time I
didn't have identifiers working.

-- 
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