Index: doc/example-scripts/traits-simple.html =================================================================== diff -u -r93bb0947d582f274afb1cdbc885909d55e100b36 -rc4f449cb353be812ba6502ef8e9587e87881f59b --- doc/example-scripts/traits-simple.html (.../traits-simple.html) (revision 93bb0947d582f274afb1cdbc885909d55e100b36) +++ doc/example-scripts/traits-simple.html (.../traits-simple.html) (revision c4f449cb353be812ba6502ef8e9587e87881f59b) @@ -1,866 +1,866 @@ - - - - - -Listing of doc/example-scripts/traits-simple.tcl - - - - - -
-
-
-

Implementation study based on

-
    -
  1. -

    -Ducasse, O. Nierstrasz, N. Schärli, R. Wuyts, A. Black: - Traits: A Mechanism for Fine-grained Reuse, - ACM transactions on Programming Language Systems, Vol 28, No 2, March 2006 -

    -
    2. -
-

Example in Fig 12: ReadStream and Trait tReadStream

-

In this example, traits are used to extend classes and other traits.

-
-
-
package require nx::trait
-

Create a simple trait called tReadStream which provides the -interface to a stream. In contrary to a composite trait, a simple -trait does not inherit from another trait.

-
-
-
nx::Trait create tReadStream {
-  #
-  # Define the methods provided by this trait:
-  #
-  :public method atStart {} {expr {[:position] == [:minPosition]}}
-  :public method atEnd {} {expr {[:position] == [:maxPosition]}}
-  :public method setToStart {} {set :position [:minPosition]}
-  :public method setToEnd {} {set :position [:maxPosition]}
-  :public method maxPosition {} {llength ${:collection}}
-  :public method on {collection} {set :collection $collection; :setToStart}
-  :public method next {} {
-    if {[:atEnd]} {return ""} else {
-      set r [lindex ${:collection} ${:position}]
-      :nextPosition
-      return $r
-    }
-  }
-  :public method minPosition {} {return 0}
-  :public method nextPosition {} {incr :position 1}
-
-  # This trait requires a method "position" and a variable
-  # "collection" from the base class. The definition is incomplete in
-  # these regards.
-
-  :requiredMethods position
-  :requiredVariables collection
-}
-

Define the class ReadStream with properties position and -collection that uses the trait. The method require trait checks the -requirements of the trait and imports the methods into ReadStream.

-
-
-
nx::Class create ReadStream {
-  :property {collection ""}
-  :property -accessor public {position 0}
-  :require trait tReadStream
-}
-

Create an instance of the class ReadStream:

-
-
-
ReadStream create r1 -collection {a b c d e}
-

Test the behavior of the composed class:

-
-
-
% r1 atStart
-1
-% r1 atEnd
-0
-% r1 next
-a
-% r1 next
-b
-
-
-
-
- - - + + + + + +Listing of doc/example-scripts/traits-simple.tcl + + + + + +
+
+
+

Implementation study based on

+
    +
  1. +

    +Ducasse, O. Nierstrasz, N. Schärli, R. Wuyts, A. Black: + Traits: A Mechanism for Fine-grained Reuse, + ACM transactions on Programming Language Systems, Vol 28, No 2, March 2006 +

    +
    2. +
+

Example in Fig 12: ReadStream and Trait tReadStream

+

In this example, traits are used to extend classes and other traits.

+
+
+
package require nx::trait
+

Create a simple trait called tReadStream which provides the +interface to a stream. In contrary to a composite trait, a simple +trait does not inherit from another trait.

+
+
+
nx::Trait create tReadStream {
+  #
+  # Define the methods provided by this trait:
+  #
+  :public method atStart {} {expr {[:position] == [:minPosition]}}
+  :public method atEnd {} {expr {[:position] == [:maxPosition]}}
+  :public method setToStart {} {set :position [:minPosition]}
+  :public method setToEnd {} {set :position [:maxPosition]}
+  :public method maxPosition {} {llength ${:collection}}
+  :public method on {collection} {set :collection $collection; :setToStart}
+  :public method next {} {
+    if {[:atEnd]} {return ""} else {
+      set r [lindex ${:collection} ${:position}]
+      :nextPosition
+      return $r
+    }
+  }
+  :public method minPosition {} {return 0}
+  :public method nextPosition {} {incr :position 1}
+
+  # This trait requires a method "position" and a variable
+  # "collection" from the base class. The definition is incomplete in
+  # these regards.
+
+  :requiredMethods position
+  :requiredVariables collection
+}
+

Define the class ReadStream with properties position and +collection that uses the trait. The method require trait checks the +requirements of the trait and imports the methods into ReadStream.

+
+
+
nx::Class create ReadStream {
+  :property {collection ""}
+  :property -accessor public {position 0}
+  :require trait tReadStream
+}
+

Create an instance of the class ReadStream:

+
+
+
ReadStream create r1 -collection {a b c d e}
+

Test the behavior of the composed class:

+
+
+
% r1 atStart
+1
+% r1 atEnd
+0
+% r1 next
+a
+% r1 next
+b
+
+
+
+
+ + +