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-rw-r--r--doc/DoubleObj.367
1 files changed, 27 insertions, 40 deletions
diff --git a/doc/DoubleObj.3 b/doc/DoubleObj.3
index 4af284d..ea62c07 100644
--- a/doc/DoubleObj.3
+++ b/doc/DoubleObj.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: DoubleObj.3,v 1.3 2004/09/06 09:44:56 dkf Exp $
+'\" RCS: @(#) $Id: DoubleObj.3,v 1.4 2006/04/25 17:15:25 dgp Exp $
'\"
.so man.macros
.TH Tcl_DoubleObj 3 8.0 Tcl "Tcl Library Procedures"
@@ -25,55 +25,42 @@ int
.SH ARGUMENTS
.AS Tcl_Interp doubleValue in/out
.AP double doubleValue in
-A double-precision floating-point value used to initialize or set a double object.
+A double-precision floating-point value used to initialize or set a Tcl object.
.AP Tcl_Obj *objPtr in/out
-For \fBTcl_SetDoubleObj\fR, this points to the object to be converted
-to double type.
+For \fBTcl_SetDoubleObj\fR, this points to the object in which to store a
+double value.
For \fBTcl_GetDoubleFromObj\fR, this refers to the object
-from which to get a double value;
-if \fIobjPtr\fR does not already point to a double object,
-an attempt will be made to convert it to one.
+from which to retrieve a double value.
.AP Tcl_Interp *interp in/out
-If an error occurs during conversion,
-an error message is left in the interpreter's result object
-unless \fIinterp\fR is NULL.
+When non-NULL, an error message is left here when double value retrieval fails.
.AP double *doublePtr out
-Points to place to store the double value
-obtained from \fIobjPtr\fR.
+Points to place to store the double value obtained from \fIobjPtr\fR.
.BE
.SH DESCRIPTION
.PP
-These procedures are used to create, modify, and read
-double Tcl objects from C code.
-\fBTcl_NewDoubleObj\fR and \fBTcl_SetDoubleObj\fR
-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-precision floating-point value given by \fIdoubleValue\fR;
-\fBTcl_NewDoubleObj\fR 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 double value to the object's internal representation
-\fIdoubleValue\fR member.
-\fBTcl_SetDoubleObj\fR invalidates any old string representation
-and, if the object is not already a double object,
-frees any old internal representation.
+These procedures are used to create, modify, and read Tcl objects that
+hold double-precision floating-point values.
.PP
-\fBTcl_GetDoubleFromObj\fR attempts to return a double value
-from the Tcl object \fIobjPtr\fR.
-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 \fBTCL_ERROR\fR
-and leaves an error message in the interpreter's result object
-unless \fIinterp\fR is NULL.
-Otherwise, it returns \fBTCL_OK\fR and stores the double value
-in the address given by \fIdoublePtr\fR.
-If the object is not already a double object,
-the conversion will free any old internal representation.
-
+\fBTcl_NewDoubleObj\fR creates and returns a new Tcl object initialized to
+the double value \fIdoubleValue\fR. The returned Tcl object is unshared.
+.PP
+\fBTcl_SetDoubleObj\fR sets the value of an existing Tcl object pointed to
+by \fIobjPtr\fR to the double value \fIdoubleValue\fR. The \fIobjPtr\fR
+argument must point to an unshared Tcl object. Any attempt to set the value
+of a shared Tcl object violates Tcl's copy-on-write policy. Any existing
+string representation or internal representation in the unshared Tcl object
+will be freed as a consequence of setting the new value.
+.PP
+\fBTcl_GetDoubleFromObj\fR attempts to retreive a double value from the
+Tcl object \fIobjPtr\fR. If the attempt succeeds, then \fBTCL_OK\fR is
+returned, and the double value is written to the storage pointed to by
+\fIdoublePtr\fR. If the attempt fails, then \fBTCL_ERROR\fR is returned,
+and if \fIinterp\fR is non-NULL, an error message is left in \fIinterp\fR.
+The \fBTcl_ObjType\fR of \fIobjPtr\fR may be changed to make subsequent
+calls to \fBTcl_GetDoubleFromObj\fR more efficient.
+'\" TODO: add discussion of treatment of NaN value
.SH "SEE ALSO"
Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult
-
.SH KEYWORDS
double, double object, double type, internal representation, object, object type, string representation