Type Alias ValueBindings 

pub type ValueBindings = HashMap<ParameterName, Value>;

Parameter-name → value lookup passed to Expression::eval.

Aliased rather than newtyped so callers can build bindings however is convenient — from iterators, from a hand-constructed HashMap, whatever. A later slice can upgrade this to a trait once the plan- binder lands.

Aliased Type

pub struct ValueBindings { /* private fields */ }