5.4.2.1 Call Statement

Note

This section describes the implementation of MS-VBAL §5.4.2.1 Call Statement.

Syntax

AST node	Instruction kind(s)	Notes
CallStatementNode	`Simple`	A `Call` statement or a bare call.

See RD-VBAL §3.4.2 Simple Statements and RD-VBAL §3.5.2 Instruction.

Static Semantics

What a call statement calls is a procedure: a Sub, a Function or a Property, of the workspace, of a library or a Declare. A variable or a constant is none, and a call statement written on one is a compile error, with Call or without, as it is in MS-VBA (recorded in Excel):

What the statement names	Example	Outcome
A variable or a constant of the procedure, a parameter included	`Dim x As Long` … `x (1)`, `x`, `Call x`	`VBC09364` Expected Sub, Function, or Property
A variable or a constant of a module, bare or qualified	`Count (1)`, `Globals.Count (1)`, `Call Count`	`VBC09370` Expected procedure, not variable
A variable of an object, without `Call`	`Dim c As New Collection` … `c (1)`	Valid: the statement calls the object's default member.

A Variant is no object: a call statement on one is the error, whatever it holds. A variable hides a procedure of the same name in the procedure that declares it, so P (1) in a procedure that declares Dim p As Long is VBC09364, though the module has a Sub P.

Runtime Semantics

A Call statement or a bare-call statement whose callee is a bare name (Foo, Foo(...), Call Foo(...)) invokes it through a callable binding (ICallableBindingFactory):

Callee	Invoked through
A procedure of the workspace	IProcedureInvoker
A member with an external target (a standard-library member)	IExternalDispatcher (RD-VBAL §6.0 Standard Library)

The unparenthesized argument form of a bare-call statement (Foo 1, 2, p.Grow 2) and a callee reached through a member access (obj.Foo, Call obj.Foo(1)) are invoked the same way: a member of an object, of a module (Strings.LenB) or of a project (VBA.LenB) is a callee like any other (RD-VBAL §5.6.12).

A bare reference to a Sub, Function or Property Get invokes a procedure the same way (RD-VBAL §5.3.1.11 Procedure Invocation Argument Processing, RD-VBAL §5.6.10 Simple Name Expressions).

A callee's run-time error propagates like any other run-time error. The callee's error result (RuntimeSemanticsEvaluationResult) is converted back into an Error outcome by the caller's ExecuteCall.

Implementation

A Simple instruction is dispatched by its statement type through RDCore.Runtime.Semantics.Statements.IStatementRuntimeSemanticsProvider (RD-VBAL §3.5.4 Execution); ExecuteCall handles a CallStatementNode.
RDCore.Runtime.Execution.RuntimeProcedureInvoker is the IProcedureInvoker implementation.
RDCore.Runtime.Execution.RuntimeCallableBindingFactory is the ICallableBindingFactory implementation. A member that carries SymbolProperties.ExternalTarget is bound to the external dispatcher; any other member is bound to the procedure invoker.