12 Dec
2008
12 Dec
'08
5:41 p.m.
On 11-12 22:01, Andrei Pelinescu-Onciul wrote:
It would be better to have different operators for strings and for
integers. Right now we have '+', '==' and '!=' that can be used
both for
strings and integers. The problem with this approach is that it makes
some optimizations impossible, especially when combined with dynamic
typed variables (avps or pvars). '+' is especially bad because one
can tell what type ($v + x) has only at runtime.
I would like to preserve the original behaviour for strings. They are used
much more often than integers. If you need to change anything then, please,
consider changing the behaviour of integer operators.
I think having perl like operators would help a lot:
- '.' for string concatenation (instead of reusing '+'), e.g.:
$v= "foo" . "bar"
Yes, I like this one.
- 'eq' instead of == for strings, e.g.: $v eq
"bar"
- 'ne' instead of != for strings, e.g.: $v ne "bar"
I don't like this. If there really is a need to have separate operators then
use 'eq' and 'ne' for integers and keep == and != for strings. Test (see
man
test) has string and integer operators this way.
We could support them right now in parallel with the
old ones and
obsolete +, == and != for strings in the future (but that means we
still cannot optimize '+' in all the cases) or switch right now
(maybe with some old compat switch which will support old scripts
style).
The question is how much are they used right now. While I think '==' and
'!=' are used quite often, I'm not sure about '+' for strings (and
'+'
is the most important anyway).
I guess == and != are used most often with strings.
Note: we can still support '==' and
'!=' for condition tests not
involving variables (e.g. method=="INVITE", uri=="sip:foo" a.s.o.).
That would be inconsistent. if (method=="INVITE") would work, but
if ($abc=="foo") would not work if strings operators are replaced with
'eq'
and 'ne'.
Jan.