diff options
Diffstat (limited to 'doc/upvar.n')
| -rw-r--r-- | doc/upvar.n | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/doc/upvar.n b/doc/upvar.n index 214aea9..8242a43 100644 --- a/doc/upvar.n +++ b/doc/upvar.n @@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: upvar.n,v 1.16 2007/12/13 15:22:33 dgp Exp $ +'\" RCS: @(#) $Id: upvar.n,v 1.17 2008/10/17 10:22:25 dkf Exp $ '\" .so man.macros .TH upvar n "" Tcl "Tcl Built-In Commands" @@ -45,12 +45,14 @@ The \fBupvar\fR command simplifies the implementation of call-by-name procedure calling and also makes it easier to build new control constructs as Tcl procedures. For example, consider the following procedure: +.PP .CS proc \fIadd2\fR name { \fBupvar\fR $name x set x [expr {$x + 2}] } .CE +.PP If \fIadd2\fR is invoked with an argument giving the name of a variable, it adds two to the value of that variable. Although \fIadd2\fR could have been implemented using \fBuplevel\fR @@ -85,6 +87,7 @@ will be .QW "\fIlocalVar\fR" rather than .QW "\fIoriginalVar\fR" : +.PP .CS proc \fItraceproc\fR { name index op } { puts $name @@ -106,15 +109,17 @@ made to \fImyVar\fR will not be passed to subprocesses correctly. .SH EXAMPLE A \fBdecr\fR command that works like \fBincr\fR except it subtracts the value from the variable instead of adding it: +.PP .CS proc decr {varName {decrement 1}} { \fBupvar\fR 1 $varName var incr var [expr {-$decrement}] } .CE - .SH "SEE ALSO" global(n), namespace(n), uplevel(n), variable(n) - .SH KEYWORDS context, frame, global, level, namespace, procedure, variable +.\" Local Variables: +.\" mode: nroff +.\" End: |