Module constraint

Structs§

AllEqualTypeConstraint: A type constraint that requires all or some arguments to have the same type.
Assignment: A mapping from variables to their assigned values. This is the result of constraint solving. Uses an immutable HashMap for efficient cloning during constraint solving.
Problem: A constraint satisfaction problem consisting of constraints and a range of variables to solve for. The problem is considered solved when all variables in the range are assigned.
SimpleTypeConstraint: A type constraint that assigns specific sorts to each argument position. Constructs a set of Assign constraints that fully constrain the type of arguments.

ConstraintError: Errors that can occur during constraint solving. These represent various ways that constraint satisfaction can fail.
ImpossibleConstraint: Represents constraints that are logically impossible to satisfy. These are used to signal type errors during constraint solving.

Constraint: A constraint that can be applied to variable assignments. Constraints are used in type inference to represent relationships between variables and values.
TypeConstraint: A trait for generating type constraints from atom applications. This is used to create constraints that ensure proper typing of function/primitive applications.

and: Creates a conjunction constraint that requires all sub-constraints to be satisfied.
assign: Creates an assignment constraint that binds a variable to a specific value. The constraint fails if the variable is already assigned to a different value.
eq: Creates an equality constraint between two variables. If one of the variable has a known value, the constraint propagates value to the other variable. If both variables have known but different values, the constraint fails.
implies: Creates an implication constraint that activates when all watch variables are assigned. The constraint function is called with the values of the watch variables to generate the actual constraint.
impossible: Creates a constraint that always fails with the given impossible constraint. This is used to signal type errors during constraint solving.
xor: Creates an exclusive-or constraint that requires exactly one sub-constraint to be satisfied. The constraint proceeds if exactly one sub-constraint can be satisfied and all others lead to failure. The constraint fails if zero sub-constraints can be satisfied.