NAME

       Tcl_NewBooleanObj,  Tcl_SetBooleanObj,  Tcl_GetBooleanFro­
       mObj - manipulate Tcl objects as boolean values


SYNOPSIS

       #include <tcl.h>

       Tcl_Obj *
       Tcl_NewBooleanObj(boolValue)

       Tcl_SetBooleanObj(objPtr, boolValue)

       int
       Tcl_GetBooleanFromObj(interp, objPtr, boolPtr)


ARGUMENTS

       int          boolValue (in)      Integer  value  used   to
                                        initialize   or   set   a
                                        boolean object.   If  the
                                        integer  is  nonzero, the
                                        boolean object is set  to
                                        1;  otherwise the boolean
                                        object is set to 0.

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

       Tcl_Interp   *interp   (in/out)  If an error occurs during
                                        conversion, an error mes­
                                        sage   is   left  in  the
                                        interpreter's      result
                                        object  unless  interp is
                                        NULL.

       int          *boolPtr  (out)     Points  to  place   where
                                        Tcl_GetBooleanFromObj
                                        stores the boolean  value
                                        (0  or  1)  obtained from
                                        objPtr.
_________________________________________________________________

       These procedures are used  to  create,  modify,  and  read
       boolean  Tcl  objects  from C code.  Tcl_NewBooleanObj and
       Tcl_SetBooleanObj will create a new object of boolean type
       or  modify  an existing object to have boolean type.  Both
       of these procedures set the object  to  have  the  boolean
       value  (0  or  1)  specified by boolValue; if boolValue is
       nonzero, the object is set to 1, otherwise to 0.  Tcl_New­
       BooleanObj  returns  a  pointer  to a newly created object
       with  reference  count  zero.   Both  procedures  set  the
       object's  type  to be boolean and assign the boolean value
       to the object's internal representation longValue  member.
       Tcl_SetBooleanObj  invalidates  any old string representa­
       tion and, if the object is not already a  boolean  object,
       frees any old internal representation.

       Tcl_GetBooleanFromObj  attempts  to return a boolean value
       from the Tcl object objPtr.  If the object is not  already
       a  boolean  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,  Tcl_GetBoolean­
       FromObj returns TCL_OK and stores the boolean value in the
       address given by boolPtr.  If the object is not already  a
       boolean  object, the conversion will free any old internal
       representation.



SEE ALSO

       Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetOb­
       jResult



KEYWORDS

       boolean,  boolean object, boolean type, internal represen­
       tation, object, object type, string representation