`Declare` Statement

Makes a wrapper for a procedure.

Syntax

One-line construct

[ @Platform platform_name ] _
Declare [ library_name [ flags ] ] { Function | Sub } name _
  [ Is canonical_name ] [ parameter_list ]

Block construct

[ @Platform platform_name ] _
Declare library_name [ flags ]
  { Function | Sub } name [ Is canonical_name ] [ parameter_list ]
  …
End [ Declare ]

Parts

@Platform

Optional modifier tells the compiler that the element(s) is/are available only on the given platform.

platform_name

Mandatory after @Platform, the name of a platform. See @Platform for a full list.

library_name

Optional string literal with the name of a compiled library, for example, a dynamic link library (DLL).

flags

Optional one or more non-reserved keywords. A comma between each is optional.

ANSI – Strings are 8-bit ANSI. Cannot use with UTF16.
CDECL – Uses the C calling convention.
UTF16 – Strings are 16-bit Unicode. Cannot use with ANSI.

name

Mandatory name for the wrapper procedure.

canonical_name

If library_name is given, an optional string literal, when the exported name is different.

If library_name is not given, name becomes an alternative name for the procedure canonical_named.

parameter_list

Optional. See Parameter List for more information.

If library_name is not given, a different construct is used.

Parameter list

( mandatory_params [ Optional optional_param [ = default ] [ , optional_params ] ] )

mandatory_params: One or more integer literals, with a comma between each. Use 1 for the initial parameter, 2 for the second, thru all mandatory parameters. You can write the parameters out of sequence.
optional_param: Mandatory after Optional – an integer literal.
default: Optional expression.
optional_params: Optional one or more subsequent parameters, with a comma between each. Each can have a default value.

End

Completes the block construct. You can also use End Declare.

You can change the syntax of this part. See @Option Directive for more information.

Instructions

TODO

Give procedures alternative names.
Import procedures from compiled libraries.
Change the sequence of parameters.
Make mandatory parameters optional, with default values.
Make optional parameters mandatory, or change their default values.

Examples

Alternative names

Declare Function MyAlias1 Is SomeNamespace.SomeFunction
Declare Function MyAlias2 Is SomeOtherFunction(1, 2, Optional 3=False, 4=0.0)
Declare Function TwoArgs Is FourArgs(3, 2, Optional 1=0, 4=0)

Foreign function libraries

Declare "user32.dll" Function BringWindowToTop (
    h As Int32) As Int32
Declare "user32.dll" UTF16 Function SetWindowText Is "SetWindowTextW" (
    h As Int32, s As String ) As Int32

Declare "user32.dll" UTF16
    Function BringWindowToTop (
        h As Int32) As Int32
    Function SetWindowText Is "SetWindowTextW" (
        h As Int32, s As String) As Int32
End Declare

Declare Statement