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diff --git a/doc/uplevel.n b/doc/uplevel.n deleted file mode 100644 index 83290d3..0000000 --- a/doc/uplevel.n +++ /dev/null @@ -1,80 +0,0 @@ -'\" -'\" Copyright (c) 1993 The Regents of the University of California. -'\" Copyright (c) 1994-1997 Sun Microsystems, Inc. -'\" -'\" See the file "license.terms" for information on usage and redistribution -'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -'\" -'\" RCS: @(#) $Id: uplevel.n,v 1.2 1998/09/14 18:39:56 stanton Exp $ -'\" -.so man.macros -.TH uplevel n "" Tcl "Tcl Built-In Commands" -.BS -'\" Note: do not modify the .SH NAME line immediately below! -.SH NAME -uplevel \- Execute a script in a different stack frame -.SH SYNOPSIS -\fBuplevel \fR?\fIlevel\fR?\fI arg \fR?\fIarg ...\fR? -.BE - -.SH DESCRIPTION -.PP -All of the \fIarg\fR arguments are concatenated as if they had -been passed to \fBconcat\fR; the result is then evaluated in the -variable context indicated by \fIlevel\fR. \fBUplevel\fR returns -the result of that evaluation. -.PP -If \fIlevel\fR is an integer then -it gives a distance (up the procedure calling stack) to move before -executing the command. If \fIlevel\fR consists of \fB#\fR followed by -a number then the number gives an absolute level number. If \fIlevel\fR -is omitted then it defaults to \fB1\fR. \fILevel\fR cannot be -defaulted if the first \fIcommand\fR argument starts with a digit or \fB#\fR. -.PP -For example, suppose that procedure \fBa\fR was invoked -from top-level, and that it called \fBb\fR, and that \fBb\fR called \fBc\fR. -Suppose that \fBc\fR invokes the \fBuplevel\fR command. If \fIlevel\fR -is \fB1\fR or \fB#2\fR or omitted, then the command will be executed -in the variable context of \fBb\fR. If \fIlevel\fR is \fB2\fR or \fB#1\fR -then the command will be executed in the variable context of \fBa\fR. -If \fIlevel\fR is \fB3\fR or \fB#0\fR then the command will be executed -at top-level (only global variables will be visible). -.PP -The \fBuplevel\fR command causes the invoking procedure to disappear -from the procedure calling stack while the command is being executed. -In the above example, suppose \fBc\fR invokes the command -.CS -\fBuplevel 1 {set x 43; d}\fR -.CE -where \fBd\fR is another Tcl procedure. The \fBset\fR command will -modify the variable \fBx\fR in \fBb\fR's context, and \fBd\fR will execute -at level 3, as if called from \fBb\fR. If it in turn executes -the command -.CS -\fBuplevel {set x 42}\fR -.CE -then the \fBset\fR command will modify the same variable \fBx\fR in \fBb\fR's -context: the procedure \fBc\fR does not appear to be on the call stack -when \fBd\fR is executing. The command ``\fBinfo level\fR'' may -be used to obtain the level of the current procedure. -.PP -\fBUplevel\fR makes it possible to implement new control -constructs as Tcl procedures (for example, \fBuplevel\fR could -be used to implement the \fBwhile\fR construct as a Tcl procedure). -.PP -\fBnamespace eval\fR is another way (besides procedure calls) -that the Tcl naming context can change. -It adds a call frame to the stack to represent the namespace context. -This means each \fBnamespace eval\fR command -counts as another call level for \fBuplevel\fR and \fBupvar\fR commands. -For example, \fBinfo level 1\fR will return a list -describing a command that is either -the outermost procedure call or the outermost \fBnamespace eval\fR command. -Also, \fBuplevel #0\fR evaluates a script -at top-level in the outermost namespace (the global namespace). - -.SH "SEE ALSO" -namespace(n) - -.SH KEYWORDS -context, level, namespace, stack frame, variables |