Interface IExternalDispatcher
Runs a call to something outside the workspace.
public interface IExternalDispatcherRemarks
The counterpart of IProcedureInvoker, which runs the workspace's own procedures. The two are chosen between by one fact: a workspace procedure has an instruction list, an external member has a ExternalTarget. Nothing above that point — the resolver, the expression evaluator, the executor, the semantics — is aware of the difference, which is the whole reason this is shaped like the invoker it sits beside.
🎯 Implementations are expected to be composed rather than singular: an availability check, then the
workspace's own policy, then whatever is intercepting calls (a log, a mock), and only then the provider
that really runs it. A call that is refused, or answered by an interceptor, never reaches a provider —
which is what makes a Declare blockable and a MsgBox mockable without either of them
knowing.
⚖️RDCore provides implementations of this interface licensed under GPLv3.
Methods
Invoke(ExternalCallRequest, ISymbolResolver)
Runs request and returns what it yielded, the way the semantics of the language
do: an error is in the result rather than thrown.
RuntimeSemanticsEvaluationResult Invoke(ExternalCallRequest request, ISymbolResolver resolver)Parameters
requestExternalCallRequestThe call to run.
resolverISymbolResolverA read-only interface over the current execution context.
Returns
Remarks
A member this dispatcher cannot reach — no implementation, no provider, or a policy that refuses it — is a run-time error saying so, not an internal error and never a silent success. A workspace can trap it like any other.