DIP 50 - AST macros

[Ellery Newcomer]

On 11/17/2013 11:41 AM, Simen Kjærås wrote:
>
> Source is attached. I hope God forgives me.
>

I suppose you'd have to do something like

x.Where(OR( NOT(Args.thing = "thing"), Args.sing = "sing"))

for nesting and negation and all that.

I'd wait for walter to relax the restrictions on ==, &&, etc operator 
overloading. Then you probably could do

x.Where(X => X.thing != "thing" || X.sing == "sing")

let's see here. If X's type is QueryExp!Entity and the return type is 
SomeRange!Entity then querying looks doable.

how about composing expressions? take the result of that lambda EXP,
EXP = EXP && X.cling == 1; // should work fine?

how about decomposing expressions?
EXP = EXP.lhs; // should work fine?

EXP.rhs.rhs.value // returns "sing" - should work fine? the lambda 
should create a closure, so we should be able to get out any value we put in

you won't be able to do

x.Where(X => upper(X.thing) == "THING")

without ast macros but will have to be satisfied with

x.Where(X => X.thing.upper() == "THING")

will you be able to do

x.Where(X => X.thing == "THING" && x.Any(X2 => X2.thing == X.thing && 
X2.id != X.id))

?

either "Any" would have to be only for template expressions, or X would 
have to be an outer context like so:

x.Where(X => X.it.thing == "THING" && X.x.Any(X2 => X2.it.thing == 
X.it.thing && X2.it.id != X.it.id))

because x.Any(...) should return bool, but inside the query expression 
it should return QueryExp. In both cases it would take a param of

QueryExp delegate(QueryExp)

Anybody else have any other ideas?