Tcl_BooleanObj(3) Tcl Library Procedures Tcl_BooleanObj(3)
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NAME
Tcl_NewBooleanObj, Tcl_SetBooleanObj, Tcl_GetBooleanFromObj - manipulate Tcl objects as boolean val-ues values
ues
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 message 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.
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DESCRIPTION
These procedures are used to create, modify, and read boolean Tcl objects from C code. Tcl_New-BooleanObj Tcl_NewBooleanObj
BooleanObj 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 Tcl_NewBooleanObj
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 representa-tion representation
tion longValue member. Tcl_SetBooleanObj invalidates any old string representation 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_GetBooleanFromObj 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. Objects having a string representation equal to any of 0,
false, no, or off have a boolean value 0; if the string representation is any of 1, true, yes, or on
the boolean value is 1. Any of these string values may be abbreviated, and upper-case spellings are
also acceptable.
SEE ALSO
Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult
KEYWORDS
boolean, boolean object, boolean type, internal representation, object, object type, string represen-tation representation
tation
Tcl 8.0 Tcl_BooleanObj(3)
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