[STD, S03] slaughter of the LTM metatokens
This cleans up the metaop scene quite a bit. Bravo!
I went through STD.pm with a fine tooth comb again, to extract what
I'd say about which operators were allowed to be meta'd by each given
metaop:
(The notation "foo --> bar" means, takes an operator of type foo and
makes an operator of type bar)
op= infix --> infix
op can't be :assoc<non>
op must be :assign
** The first test is excessive: There are no non-associative operators
that have the :assign property. Hence, testing for :assign should be
enough. Besides, I'm not sure what about this metaop should require
non-associativity from its internal operator.
!op infix --> infix
op must not start with '!'
op must return 'bool', these are the chaining ops and %
or op can be '='
** Declaring that infix:sym<%> is :returns<Bool> just so this works
seems a bit ugly to me. Why not simply define infix:sym<!%>?
** Why is the test for .text eq '=' in there? infix:sym<!=> is
already defined.
Rop infix --> infix
op must not start with '='
** The restriction seems unneeded and has odd side-effects. It is true
that there is no reason to all R== R=:= or R===, since they are the
same as their non-reversed selves. But the restriction means that:
Rp5=> is an operator, but R=> is not
R:= is an operator, but R= is not
In the first case, I'd imagine I'd want them both to be. In the
second, I imagine I'd want neither -- but not sure I care all that much.
Xop infix --> infix
op<< prefix --> prefix
>>op postfix --> postfix
>>op<< infix --> infix
++ No restrictions here... Woot!
[op] infix --> prefix
op can't be :assoc('non')
op can't have same precedence as %conditional
** The second test should probably be can't be :assoc('chain')
** Really, the restriction on the operator is that it has to return a
type that is compatible with being on its left side for a given type
on its right. There are things that are currently allowed here, like
[:=] or [=>] that may not make much sense. Perhaps there should
be :reduce like there is :assign to indicate which are
- MtnViewMark
