Tcl_DoubleObj(3)            Tcl Library Procedures            Tcl_DoubleObj(3)


       Tcl_NewDoubleObj,  Tcl_SetDoubleObj,  Tcl_GetDoubleFromObj - manipulate
       Tcl objects as floating-point values

       #include <tcl.h>

       Tcl_Obj *

       Tcl_SetDoubleObj(objPtr, doubleValue)

       Tcl_GetDoubleFromObj(interp, objPtr, doublePtr)

       double       doubleValue   (in)      A double-precision floating  point
                                            value  used to initialize or set a
                                            double object.

       Tcl_Obj      *objPtr       (in/out)  For Tcl_SetDoubleObj, this  points
                                            to  the  object to be converted to
                                            double type.   For  Tcl_GetDouble-
                                            FromObj, this refers to the object
                                            from which to get a double  value;
                                            if  objPtr  does not already point
                                            to a  double  object,  an  attempt
                                            will be made to convert it to one.

       Tcl_Interp   *interp       (in/out)  If an error occurs during  conver-
                                            sion,  an error message is left in
                                            the  interpreter's  result  object
                                            unless interp is NULL.

       double       *doublePtr    (out)     Points  to place to store the dou-
                                            ble value obtained from objPtr.

       These procedures are used  to  create,  modify,  and  read  double  Tcl
       objects from C code.  Tcl_NewDoubleObj and Tcl_SetDoubleObj will create
       a new object of double type or modify an existing object to have double
       type.   Both of these procedures set the object to have the double-pre-
       cision floating point  value  given  by  doubleValue;  Tcl_NewDoubleObj
       returns  a pointer to a newly created object with reference count zero.
       Both procedures set the object's type to be double and assign the  dou-
       ble  value  to the object's internal representation doubleValue member.
       Tcl_SetDoubleObj invalidates any old string representation and, if  the
       object is not already a double object, frees any old internal represen-

       Tcl_GetDoubleFromObj attempts to return a double  value  from  the  Tcl
       object  objPtr.   If the object is not already a double object, it will
       attempt to convert it to one.  If an error occurs during conversion, it
       returns  TCL_ERROR  and  leaves  an  error message in the interpreter's
       result object unless interp is NULL.  Otherwise, it returns TCL_OK  and
       stores  the  double  value  in  the address given by doublePtr.  If the
       object is not already a double object, the conversion will free any old
       internal representation.

       Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult

       double,  double  object,  double type, internal representation, object,
       object type, string representation

Tcl                                   8.0                     Tcl_DoubleObj(3)