For some reason one might need to know the type name of a Tcl object. The type name is stored in Tcl_Obj's typePtr->name. Below is the small C extension typeof to get the type name.
DKF: Be aware that Tcl makes no guarantee about the type of any value; basing any semantic decision on this information is strongly discouraged, which is why Tcl does not provide this operation itself.
ASV: Development of idea http://reddog.s35.xrea.com/wiki/Typeinfo.html .
/*
* typeof
* BSD License
*/
#include <tcl.h>
#ifdef WIN32
#ifdef typeof_EXPORTS
#define typeof_EXPORT __declspec(dllexport)
#else
#define typeof_EXPORT __declspec(dllimport)
#endif
#else
#define typeof_EXPORT
#endif
static int Typeof_Cmd(ClientData clientData, Tcl_Interp *interp, int argc, Tcl_Obj *const argv[]) {
if (argc != 2) {
Tcl_WrongNumArgs(interp, 1, argv, "object");
return TCL_ERROR;
}
if (argv[1]->typePtr) {
Tcl_SetObjResult(interp, Tcl_NewStringObj(argv[1]->typePtr->name, -1));
} else {
Tcl_SetObjResult(interp, Tcl_NewStringObj("string", -1));
}
return TCL_OK;
}
int typeof_EXPORT Typeof_Init(Tcl_Interp *interp) {
/*
* This may work with 8.0, but we are using strictly stubs here,
* which requires 8.1.
*/
if (Tcl_InitStubs(interp, "8.1", 0) == NULL
|| Tcl_PkgProvide(interp, "typeof", "0.1.1") != TCL_OK) {
return TCL_ERROR;
}
Tcl_CreateObjCommand(interp, "typeof", Typeof_Cmd, NULL, NULL);
return TCL_OK;
}Usage:
typeof object
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