EiffelBase2 - Revision history

Kenga: /* Iterators */

2014-04-30T11:04:53Z

‎Iterators

Kenga: /* Status and roadmap */

2012-06-27T13:22:34Z

‎Status and roadmap

Kenga: /* Sets and tables */

2012-04-11T14:19:29Z

‎Sets and tables

Kenga: /* Sets and tables */

2012-04-11T14:18:59Z

‎Sets and tables

Kenga: /* Sets and tables */

2012-04-11T14:16:49Z

‎Sets and tables

Kenga: /* Sets and tables */

2012-04-11T14:14:25Z

‎Sets and tables

Kenga: /* Sets and tables */

2012-04-11T13:34:40Z

‎Sets and tables

Kenga: /* Inheritance */

2012-04-05T15:33:31Z

‎Inheritance

Kenga: /* Status and roadmap */

2012-04-05T15:29:03Z

‎Status and roadmap

Kenga: /* Models */

2012-04-05T15:27:38Z

‎Models

@@ Line 70: / Line 70: @@
              container as i
          loop
              print (i.item)
-            i.forth
          end
      end

← Older revision		Revision as of 13:22, 27 June 2012
Line 339:		Line 339:

	It has been used in the following projects:		It has been used in the following projects:
−	* Traffic 4: modeling public transportation in a city [~~http~~://~~traffic.origo.ethz~~.ch/ ~~http~~://~~traffic.origo.ethz~~.ch/]	+	* Traffic 4: modeling public transportation in a city [https://bitbucket.org/nadiapolikarpova/traffic https://bitbucket.org/nadiapolikarpova/traffic]

@@ Line 175: / Line 175: @@
              -- Drive `c' away, repaint it and update its view.
          require
-             car_on_map: cars.has_key (c)
+             car_in_city: cars.has_key (c)
          do
              c.move (100, 100) -- change location

@@ Line 170: / Line 170: @@
 feature
      cars: V_HASH_TABLE [CAR, CAR_VIEW]
      escape_police (c: CAR)
          require
              car_on_map: cars.has_key (c)

← Older revision		Revision as of 14:16, 11 April 2012
Line 166:		Line 166:


−	class ~~MAP~~	+	class GUI_APPLICATION

	feature		feature

@@ Line 147: / Line 147: @@
 Sometimes you want to use an object as a key in a table,
 but the content of the object can change, so you cannot derive a hash code (or order) from any of its attributes.
-EiffelBase2 provides a utility class <e>V_REFERNCE_HASHABLE</e>,
+EiffelBase2 provides a utility class <e>V_REFERENCE_HASHABLE</e>,
 which derives a hash code from the object's identity rather than its content.
 For example:

← Older revision		Revision as of 13:34, 11 April 2012
Line 144:		Line 144:

	Similar style applies to <e>V_HASH_SET</e> and <e>V_GENERAL_HASH_SET</e>, <e>V_SORTED_TABLE</e> and <e>V_GENERAL_SORTED_TABLE</e>, <e>V_SORTED_SET</e> and <e>V_GENERAL_SORTED_SET</e>.		Similar style applies to <e>V_HASH_SET</e> and <e>V_GENERAL_HASH_SET</e>, <e>V_SORTED_TABLE</e> and <e>V_GENERAL_SORTED_TABLE</e>, <e>V_SORTED_SET</e> and <e>V_GENERAL_SORTED_SET</e>.
		+
		+	Sometimes you want to use an object as a key in a table,
		+	but the content of the object can change, so you cannot derive a hash code (or order) from any of its attributes.
		+	EiffelBase2 provides a utility class <e>V_REFERNCE_HASHABLE</e>,
		+	which derives a hash code from the object's identity rather than its content.
		+	For example:
		+	<e>
		+	class
		+	CAR
		+	inherit
		+	V_REFERENCE_HASHABLE
		+
		+	feature -- Access
		+	color: COLOR
		+
		+	location: POINT
		+
		+	feature -- Modification
		+	...
		+	end
		+
		+
		+	class MAP
		+
		+	feature
		+	cars: V_HASH_TABLE [CAR, CAR_VIEW]
		+
		+	escape_police (c: CAR)
		+	require
		+	car_on_map: cars.has_key (c)
		+	do
		+	c.move (100, 100) -- change location
		+	c.repaint (white) -- change color
		+	cars [c].update -- ... but still can be used to access its view
		+	end
		+	end
		+	</e>

	===Stream piping===		===Stream piping===

@@ Line 275: / Line 275: @@
 If a class <e>B</e> inherits from <e>A</e> it is free to choose, whether to reuse each of <e>A</e>'s model queries to represent its own model, as well as introduce new model queries. If <e>B</e> does not reuse an <e>A</e>'s model query is has to provide a ''linking invariant'': a definition of the old model query in terms of <e>B</e>'s model. Linking invariants explain the parent's model in terms of the heir's model and thus make sure that the inherited model-based contracts make sense in the heir.
-For example, suppose that <e>LIST</e> inherits directly from <e>CONTAINER</e>, whose model is a bag:
+For example, look at <e>V_SET</e>, which inherits directly from <e>V_CONTAINER</e>:
 <e>
 note
      model: bag
-class CONTAINER [G]
+class V_CONTAINER [G]
 ...
 end
 note
-     model: sequence, index
+     model: set
-class LIST [G]
+class V_SET[G]
 ...
 invariant
      ...
-     bag_domain_definition: bag.domain = sequence.range
+     bag_domain_definition: bag.domain |=| set
-     bag_definition: bag.domain.for all (agent (x: G): BOOLEAN
+     bag_definition: bag.is_constant (1)
-        do Result := bag [x] = sequence.occurrences (x) end)
 end
 </e>
-Here the linking invariant, provided as part of the class invariant in <e>LIST</e> completely defines an old model query <e>bag</e> in terms of a new  model query <e>sequence</e>.
+Here the linking invariant, provided as part of the class invariant in <e>V_SET</e> completely defines an old model query <e>bag</e> in terms of a new model query <e>set</e>.
 ==Status and roadmap==

@@ Line 299: / Line 299: @@
 EiffelBase2 is currently being developed as a project at ETH Zurich.
 It has been used in the following projects:
 * Traffic 4: modeling public transportation in a city [http://traffic.origo.ethz.ch/ http://traffic.origo.ethz.ch/]

@@ Line 177: / Line 177: @@
 note
      model: target, sequence, index
-class V_ITERATOR [G]
 feature -- Access
-     target: V_CONTAINER
+     target: V_LIST
-             -- Container to iterate over.
+             -- List to iterate over.
          deferred
          end
@@ Line 199: / Line 201: @@
 end
 </e>
-Here we declared the model of class <e>V_ITERATOR</e> consisting of tree components:
-a reference (to <e>V_CONTAINER</e>), a mathematical sequence of type <e>MML_SEQUENCE</e> and an integer index.
+Here we declared the model of class <e>V_LIST_ITERATOR</e> consisting of tree components:
 As you can see, model queries are not necessarily introduced specifically for specification purposes (as is the case with <e>sequence</e>);
 regular queries meant to be called from the code can be also reused as model queries (as <e>target</e> and <e>index</e> in this example).