diff options
Diffstat (limited to 'doc/BoolObj.3')
| -rw-r--r-- | doc/BoolObj.3 | 46 |
1 files changed, 28 insertions, 18 deletions
diff --git a/doc/BoolObj.3 b/doc/BoolObj.3 index 41c0a73..f586621 100644 --- a/doc/BoolObj.3 +++ b/doc/BoolObj.3 @@ -4,7 +4,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: BoolObj.3,v 1.5 2004/10/07 15:37:43 dkf Exp $ +'\" RCS: @(#) $Id: BoolObj.3,v 1.6 2005/04/22 15:46:51 dgp Exp $ '\" .so man.macros .TH Tcl_BooleanObj 3 8.0 Tcl "Tcl Library Procedures" @@ -65,25 +65,35 @@ and, if the object is not already a boolean object, frees any old internal representation. .PP \fBTcl_GetBooleanFromObj\fR attempts to return a boolean value -from the Tcl object \fIobjPtr\fR. -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 \fBTCL_ERROR\fR -and leaves an error message in the interpreter's result object -unless \fIinterp\fR is NULL. -Otherwise, \fBTcl_GetBooleanFromObj\fR returns \fBTCL_OK\fR -and stores the boolean value in the address given by \fIboolPtr\fR. -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 \fB0\fR, -\fBfalse\fR, \fBno\fR, or \fBoff\fR have a boolean value 0; if the -string representation is any of \fB1\fR, \fBtrue\fR, \fByes\fR, or -\fBon\fR the boolean value is 1. -Any of these string values may be abbreviated, and upper-case spellings -are also acceptable. +corresponding to the value of the Tcl object \fIobjPtr\fR. +If \fIobjPtr\fR is of the boolean type, its boolean value +is written at the address given by \fIboolPtr\fR. +If \fIobjPtr\fR has a string representation recognized by +\fBTcl_GetBoolean\fR, then \fIobjPtr\fR is converted to boolean +type and its boolean value is written at the address given +by \fIboolPtr\fR. If \fIobjPtr\fR holds any value recognized as +a number by Tcl, then if that value is zero a 0 is written at +the address given by \fIboolPtr\fR and if that +value is non-zero a 1 is written at the address given by \fIboolPtr\fR. +In all cases where a value is written at the address given +by \fIboolPtr\fR, \fBTCL_OK\fR is returned. +If the value of \fIobjPtr\fR does not meet any of the conditions +above, then \fBTCL_ERROR\fR is returned and error message is +left in the interpreter's result unless \fIinterp\fR is NULL. +.PP +Note that the routines \fBTcl_GetBooleanFromObj\fR and +\fBTcl_GetBoolean\fR are not functional equivalents. +The set of values for which \fBTcl_GetBooleanFromObj\fR +will return \fBTCL_OK\fR is strictly larger than +the set of values for which \fBTcl_GetBoolean\fR will do the same. +For example, the value "5" passed to \fBTcl_GetBooleanFromObj\fR +will lead to a \fBTCL_OK\fR return (and the boolean value 1), +while the same value passed to \fBTcl_GetBoolean\fR will lead to +a \fBTCL_ERROR\fR return. .SH "SEE ALSO" -Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult +Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult, +Tcl_GetBoolean .SH KEYWORDS boolean, boolean object, boolean type, internal representation, object, object type, string representation |