Struct move_model::ty::TypeInstantiationDerivation

pub struct TypeInstantiationDerivation {}

A helper to derive the set of instantiations for type parameters

Implementations

impl TypeInstantiationDerivation

pub fn progressive_instantiation<'a, I>( lhs_types: I, rhs_types: I, treat_lhs_type_param_as_var: bool, treat_rhs_type_param_as_var: bool, refine_lhs: bool, refine_rhs: bool, params_arity: usize, target_lhs: bool, mark_irrelevant_param_as_error: bool ) -> BTreeSet<Vec<Type>>where I: Iterator<Item = &'a Type> + Clone,

Find the set of valid instantiation combinations for all the type parameters.

The algorithm is progressive. For a list of parameters with arity params_arity = N, it

• first finds all possible instantiation for parameter at index 0 (inst_param_0) and,’
• for each instantiation in inst_param_0,
  • refines LHS or RHS types and
  • finds all possible instantiations for parameter at index 1 (inst_param_1)
  • for each instantiation in inst_param_1,
    • refines LHS or RHS types and
    • finds all possible instantiations for parameter at index 2 (inst_param_2)
    • for each instantiation in inst_param_2,
      • …… The process continues until all type parameters are analyzed (i.e., reaching the type parameter at index N).

If refine_lhs is True, refine the lhs_types after each round; same for refine_rhs.

If target_lhs is True, find instantiations for the type parameters in the lhs_types, otherwise, target the rhs_types.

If mark_irrelevant_param_as_error is True, type parameters that do not have any valid instantiation will be marked as Type::Error. Otherwise, leave the type parameter as it is.