[asterisk-dev] [Code Review] Add support in AEL for macro return values and direct assignment of them to variables and functions.

[Steve Murphy]

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Hmmmm. I see that you are doing substitutions in place when you see a macro call -- even when in an expression;
I don't think that's going to work very well in more than the simplest cases;

fred = &macro-with-return(5);

=>

Gosub(macro-with-return,s,1,...)
Set(fred=${GOSUB_RETVAL})

I just built with the patch and expanded your test case
a little, and I don't think this approach will fly 
very well.

macro test-retval (val1, val2) {
        local i=5+${val1};
        i=${i}+10*${val2};
        return ${i};
}

macro test-macro-assignment () {
        foo=40 * &test-retval(2,3);
        local bub=&test-retval(3,4);
        NoOp(foo is ${foo} and bub is ${bub});
        HASH(foo,bar)=&test-retval(9,7)+&test_retval(10,4);
        return;
}

And I'm getting syntax errors on line 11, the one with HASH().

In general, it's bad to try to do anything inside an expression in ael.y. It was everything I could do to make the scanner just collect it all and pass it in as a 'word'.

I think it'd be better to leave the
ael parser alone, and make the expr parser handle that
kind of logic in expressions... that way, we still
pack up the RHS and wrap it in $[] as we have;

fred = &macro1(x,y) + &macro2(z); 
=>
Set(fred,$[&macro1(x,y) + &macro2(z)])

Right now, if we try to do this above the expression level, you are going to have problems with calling
multiple macros, having them munge each others return
values, or limiting the syntax way more than is needful.

If you do this in main/ast_expr2.{y,fl}, then you have the ability to call the macro (somehow), and collect the 
result, atomically, and finish evaluating the expression
with no such problems.

In ast_expr, we already allow you to call asterisk functions without wrapping them in ${}:

$[ ${z} + MATH(..) ]

So, adding a macro shouldn't be impossible.

$[ &test-retval(9,7)+&test_retval(10,4) ]

should be parseable and evaluatable.

So, I propose that you might think along this line, and see what ael.y and ael.flex might do to allow this notation in exprs...


- Steve


On 2008-12-30 17:59:32, Marquis wrote:
> 
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> This is an automatically generated e-mail. To reply, visit:
> http://reviewboard.digium.com/r/114/
> -----------------------------------------------------------
> 
> (Updated 2008-12-30 17:59:32)
> 
> 
> Review request for Asterisk Developers.
> 
> 
> Summary
> -------
> 
> Add support in AEL for macro return values and direct assignment of them to variables and functions.
> 
> 
> Diffs
> -----
> 
>   /trunk/CHANGES 166832 
>   /trunk/include/asterisk/ael_structs.h 166832 
>   /trunk/include/asterisk/pval.h 166832 
>   /trunk/pbx/ael/ael-test/ael-vtest26/extensions.ael PRE-CREATION 
>   /trunk/pbx/ael/ael-test/ref.ael-vtest26 PRE-CREATION 
>   /trunk/res/ael/ael.flex 166863 
>   /trunk/res/ael/ael.y 166863 
>   /trunk/res/ael/pval.c 166863 
> 
> Diff: http://reviewboard.digium.com/r/114/diff
> 
> 
> Testing
> -------
> 
> Ran the AEL regression tests in pbx/ael/ael-test.  Also adapted much of my dialplan (used in general PBXs all over the world) to use the new assignment.
> 
> 
> Thanks,
> 
> Marquis
> 
>