plucky (3) link.3tcl.gz

NAME

       link - create link from command to method of object

SYNOPSIS

       package require tcl::oo

       link methodName ?...?
       link {commandName methodName} ?...?
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DESCRIPTION

       The  link  command is available within methods. It takes a series of one or more method names (methodName
       ...) and/or pairs of command- and method-name ({commandName methodName})  and  makes  the  named  methods
       available as commands without requiring the explicit use of the name of the object or the my command. The
       method does not need to exist at the time that the link is made; if the link command is invoked when  the
       method does not exist, the standard unknown method handling system is used.

       The  command  name  under  which  the  method becomes available defaults to the method name, except where
       explicitly specified through an alias/method pair.  Formally, every argument must be a list; if the  list
       has  two  elements,  the first element is the name of the command to create and the second element is the
       name of the method of the current object to which the command links; otherwise, the name of  the  command
       and the name of the method are the same string (the first element of the list).

       If the name of the command is not a fully-qualified command name, it will be resolved with respect to the
       current namespace (i.e., the object namespace).

EXAMPLES

       This demonstrates linking a single method in various ways. First it makes a simple link, then  a  renamed
       link,  then  an external link. Note that the method itself is unexported, but that it can still be called
       directly from outside the class.

              oo::class create ABC {
                  method Foo {} {
                      puts "This is Foo in [self]"
                  }

                  constructor {} {
                      link Foo
                      # The method Foo is now directly accessible as Foo here
                      link {bar Foo}
                      # The method Foo is now directly accessible as bar
                      link {::ExternalCall Foo}
                      # The method Foo is now directly accessible in the global
                      # namespace as ExternalCall
                  }

                  method grill {} {
                      puts "Step 1:"
                      Foo
                      puts "Step 2:"
                      bar
                  }
              }

              ABC create abc
              abc grill
                      → Step 1:
                      → This is Foo in ::abc
                      → Step 2:
                      → This is Foo in ::abc
              # Direct access via the linked command
              puts "Step 3:"; ExternalCall
                      → Step 3:
                      → This is Foo in ::abc

       This example shows that multiple linked commands can be made in a call to link, and that they can  handle
       arguments.

              oo::class create Ex {
                  constructor {} {
                      link a b c
                      # The methods a, b, and c (defined below) are all now
                      # directly accessible within methods under their own names.
                  }

                  method a {} {
                      puts "This is a"
                  }
                  method b {x} {
                      puts "This is b($x)"
                  }
                  method c {y z} {
                      puts "This is c($y,$z)"
                  }

                  method call {p q r} {
                      a
                      b $p
                      c $q $r
                  }
              }

              set o [Ex new]
              $o 3 5 7
                      → This is a
                      → This is b(3)
                      → This is c(5,7)

SEE ALSO

       interp(3tcl), my(3tcl), oo::class(3tcl), oo::define(3tcl)

KEYWORDS

       command, method, object