ExDatalog.Constraints.Type (ExDatalog v0.2.0)

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Type predicate constraint implementation for the Constraint behaviour.

Evaluates type-check constraints (:is_integer, :is_binary, :is_atom) which filter bindings based on the Elixir type of a bound value. These are unary constraints: only left is evaluated, right and result are nil.

Summary

Functions

evaluate(constraint, binding, context)

Evaluates a type predicate constraint against a binding environment.

Functions

evaluate(constraint, binding, context)

@spec evaluate(
  ExDatalog.IR.Constraint.t(),
  ExDatalog.Engine.Binding.t(),
  ExDatalog.Constraint.Context.t()
) :: {:ok, ExDatalog.Engine.Binding.t()} | :filter

Evaluates a type predicate constraint against a binding environment.

Accepts an IR.Constraint struct as produced by the compiler. Returns {:ok, binding} (unchanged) when the type check passes, or :filter when it fails or the input variable is unbound.