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Unknow state transition: LINE -> END

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0

-errorstack

INNER {returnImm {Unknow state transition: LINE -> END} {}} CALL {my render_wikit {Namespace variables} {[Martin Lemburg]: here some procedures ...

    * ... to get the full qualified name of ...
    * ... to check the existence of ...
    * ... to connect (with upvar) to ...

... a variable in the current or any parent namespace

======
 proc getFullNspcVarName {args} {
    switch -exact -- [llength $args] {
       1   {
          set nspc    [uplevel namespace current];
          set varname [lindex $args 0];
       }
       2   {
          foreach {nspc varname} $args {break;}
          
          if {[catch {namespace parent $nspc}]} {
             error "no such namespace \"$nspc\"";
          }
       }
       default   {
          error "wrong # args: should be \"getFullNspcVarName ?namespace? varname\"";
       }
    }
    
    while {![info exists ${nspc}::$varname]} {
       if {$nspc == "::"} {
          return "";
       }

       set nspc [namespace parent $nspc];
    }

    return ${nspc}::$varname;
 }
======

(See also [[[namespace] which]].)

[Martin Lemburg]:

no, "namespace which" is not comparable.

It doesn't do an recursive search over all parent namespace of the current or the given namespace.

There was a wikit-page [Dynamic variable scoping] with a procedure '''dynascope'''. This procedure provided access to variables in upper scope levels, with searching for the given variable in upper scope levels and [upvar]ing it, if found.

The '''getFullNspcVarName''' procedure provides a similar support, for searching the given variable, but not in upper scope, but namespace "levels".

======
 proc varExistsInNspc {args} {
    if {[catch {set result [uplevel getFullNspcVarName $args]} reason]} {
       error $reason;
    }

    if {$result == ""} {
       return 0;
    }

    return 1;
 }

 proc nspcVar2LocalVar {args} {
    if {[catch {set result [uplevel getFullNspcVarName $args]} reason]} {
       error $reason;
    }

    if {$result == ""} {
       return 0;
    }

    set varname [namespace tail $result];

    if {[uplevel info exists $varname]} {
       error "namespace var \"$result\" already exists";
    }
    
    uplevel upvar $result $varname;

    return 1;
 }

 # demo and test:

 if {[file tail [info script]] == [file tail $argv0]} {
    namespace eval a {
       variable a1;
       variable a2;
       variable a3;

       set a1 "a1 is a var of ::a";
       set a2 "a2 is a var of ::a";
       set a3 "a3 is a var of ::a";

       namespace eval b {
          variable b1;
          variable a2;

          set b1 "b1 is a var of ::a::b";
          set a2 "a2 is a var of ::a::b";

          puts "varExistsInNspc b1    = [varExistsInNspc b1]";
          puts "getFullNspcVarName b1 = [getFullNspcVarName b1]";
          puts "varExistsInNspc a1    = [varExistsInNspc a1]";
          puts "getFullNspcVarName a1 = [set var [getFullNspcVarName a1]]";

          if {[nspcVar2LocalVar a1]} {
             puts "connected \"$var\" to \"a1\"";
             puts "a1 = $a1";
          } else {
             puts stderr "couldn't connect to \"a1\"";
          }

          nspcVar2LocalVar a2;
       }
    }
 }

<<categories>> Uncategorized} regexp2} CALL {my render {Namespace variables} {[Martin Lemburg]: here some procedures ...

    * ... to get the full qualified name of ...
    * ... to check the existence of ...
    * ... to connect (with upvar) to ...

... a variable in the current or any parent namespace

======
 proc getFullNspcVarName {args} {
    switch -exact -- [llength $args] {
       1   {
          set nspc    [uplevel namespace current];
          set varname [lindex $args 0];
       }
       2   {
          foreach {nspc varname} $args {break;}
          
          if {[catch {namespace parent $nspc}]} {
             error "no such namespace \"$nspc\"";
          }
       }
       default   {
          error "wrong # args: should be \"getFullNspcVarName ?namespace? varname\"";
       }
    }
    
    while {![info exists ${nspc}::$varname]} {
       if {$nspc == "::"} {
          return "";
       }

       set nspc [namespace parent $nspc];
    }

    return ${nspc}::$varname;
 }
======

(See also [[[namespace] which]].)

[Martin Lemburg]:

no, "namespace which" is not comparable.

It doesn't do an recursive search over all parent namespace of the current or the given namespace.

There was a wikit-page [Dynamic variable scoping] with a procedure '''dynascope'''. This procedure provided access to variables in upper scope levels, with searching for the given variable in upper scope levels and [upvar]ing it, if found.

The '''getFullNspcVarName''' procedure provides a similar support, for searching the given variable, but not in upper scope, but namespace "levels".

======
 proc varExistsInNspc {args} {
    if {[catch {set result [uplevel getFullNspcVarName $args]} reason]} {
       error $reason;
    }

    if {$result == ""} {
       return 0;
    }

    return 1;
 }

 proc nspcVar2LocalVar {args} {
    if {[catch {set result [uplevel getFullNspcVarName $args]} reason]} {
       error $reason;
    }

    if {$result == ""} {
       return 0;
    }

    set varname [namespace tail $result];

    if {[uplevel info exists $varname]} {
       error "namespace var \"$result\" already exists";
    }
    
    uplevel upvar $result $varname;

    return 1;
 }

 # demo and test:

 if {[file tail [info script]] == [file tail $argv0]} {
    namespace eval a {
       variable a1;
       variable a2;
       variable a3;

       set a1 "a1 is a var of ::a";
       set a2 "a2 is a var of ::a";
       set a3 "a3 is a var of ::a";

       namespace eval b {
          variable b1;
          variable a2;

          set b1 "b1 is a var of ::a::b";
          set a2 "a2 is a var of ::a::b";

          puts "varExistsInNspc b1    = [varExistsInNspc b1]";
          puts "getFullNspcVarName b1 = [getFullNspcVarName b1]";
          puts "varExistsInNspc a1    = [varExistsInNspc a1]";
          puts "getFullNspcVarName a1 = [set var [getFullNspcVarName a1]]";

          if {[nspcVar2LocalVar a1]} {
             puts "connected \"$var\" to \"a1\"";
             puts "a1 = $a1";
          } else {
             puts stderr "couldn't connect to \"a1\"";
          }

          nspcVar2LocalVar a2;
       }
    }
 }

<<categories>> Uncategorized}} CALL {my revision {Namespace variables}} CALL {::oo::Obj630721 process revision/Namespace+variables} CALL {::oo::Obj630719 process}

-errorcode

NONE

-errorinfo

Unknow state transition: LINE -> END
    while executing
"error $msg"
    (class "::Wiki" method "render_wikit" line 6)
    invoked from within
"my render_$default_markup $N $C $mkup_rendering_engine"
    (class "::Wiki" method "render" line 8)
    invoked from within
"my render $name $C"
    (class "::Wiki" method "revision" line 31)
    invoked from within
"my revision $page"
    (class "::Wiki" method "process" line 56)
    invoked from within
"$server process [string trim $uri /]"

-errorline

4