Types

Type Libraries

In order to precisely describe the interface and (in some cases!) the functionality of a COM object, COM defines a language independant mechanism for describing types, called Type Libraries. You can think of these as a machine readable superset of header files. Using Type Libraries, the interfaces (more about these later), methods, events and properties of an object can be accurrately described.

Having this kind of information is very important as it can a) allow for the accurate type conversion between Tcl objects and COM types, and b) speed up an invocation on an object.

OpTcl is now type library aware - at least in terms of reading them and being type sensitive in its invocations. I have a test version that can write out new libraries, and wrap Tcl scripts as fully-fledged ActiveX objects - more about this later...

In OpTcl, types are represented as a strings comprising of the programmatic name for a type library and its contained typename, joined using a dot. So for example, stdole.IFontDisp is the IFontDisp type defined in the library called stdole.

Primitive Types

The only exception to the formatting rule specified above are primitive. These are always a single word with no '.' delimiter. They are listed in the following table:

Type	Description	Type	Description
char	A single character	string	single byte string
uchar	An unsigned character	carray	C-style array - not currently supported
short	16 bit signed integer	decimal	96-bit number
ushort	16 bit unsigned integer	float	32 bit real number
long	32 bit signed integer	double	64 bit real number
ulong	32 bit unsigned integer	dispatch	Scriptable interface to an object
bool	boolean	interface	Non-scriptable interface to an object
date	Date type.	currency	Currency. Range: ±922337203685477.5807
any	A variant type.