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Reduce re-allocations in eval

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greg 2017-01-05 03:47:52 -08:00
parent 8651839a66
commit dc81d237c5
1 changed files with 10 additions and 8 deletions
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18
src/eval.rs
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@ -165,17 +165,18 @@ impl<'a> Evaluator<'a> {
Some(expr) => (expr, None),
}
}
BinExp(op, box left, box right) => {
BinExp(op, mut left, mut right) => {
if right.is_reducible() {
let new = self.reduce_expr(right);
return (BinExp(op, Box::new(left), Box::new(new.0)), new.1);
let mut side_effect = None;
take_mut::take(right.as_mut(), |expr| { let (a, b) = self.reduce_expr(expr); side_effect = b; a});
return (BinExp(op, left, right), side_effect);
}
// special case for variable assignment
if *op == "=" {
match left {
match *left {
Variable(var) => {
let binding = SideEffect::AddBinding(var, right);
let binding = SideEffect::AddBinding(var, *right);
return (Null, Some(binding));
}
_ => return (Null, None),
@ -183,10 +184,11 @@ impl<'a> Evaluator<'a> {
}
if left.is_reducible() {
let new = self.reduce_expr(left);
(BinExp(op, Box::new(new.0), Box::new(right)), new.1)
let mut side_effect = None;
take_mut::take(left.as_mut(), |expr| { let (a, b) = self.reduce_expr(expr); side_effect = b; a});
(BinExp(op, left, right), side_effect)
} else {
(self.reduce_binop(op, left, right), None) //can assume both arguments are maximally reduced
(self.reduce_binop(op, *left, *right), None) //can assume both arguments are maximally reduced
}
}
Call(name, mut args) => {