Enum FusedPattern 

pub enum FusedPattern<'a> {
    RangeSum {
        start: Option<&'a Node>,
        end: &'a Node,
    },
}

A high-level fusion pattern recognised at the AST level. Each variant borrows the relevant sub-expressions straight off the AST so consumers can re-evaluate / re-lower them in their own context (interpreter scope or IR LowerCtx).

Variants

RangeSum

list.sum(range(end)) or list.sum(range(start, end)) with no intervening .map(...) / .filter(...) stages.

Equivalent fused semantics (the byte-exact contract every back-end and the interpreter must honour):

acc: i64 = 0
for i in start..end {        // empty when start >= end
    acc = acc.checked_add(i)?   // NumericOverflow on overflow
}
result = Int(acc)

This is a fusion (drop the intermediate Vec<Value> allocation), not a closed-form substitution: the same additions happen in the same order with the same checked-overflow behaviour as [start, .., end-1].sum() — the first overflowing partial sum raises NumericOverflow. start defaults to 0 for the one-arg range(end) form.

Fields

start: Option<&'a Node>

start argument node when range(start, end); None for the one-arg range(end) form (implicit start = 0).

end: &'a Node

end argument node — always present.

Trait Implementations

impl<'a> Debug for FusedPattern<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.