C++ - . - . Eiffel Smalltalk.
Window Eiffel C++:
class WINDOW
export
add_box, add_circle, clear_selections, cut_selections,
group_selections, move_selections,
redraw_all, select_item, ungroup_selections
feature
xmin, ymin, xmax, ymax: REAL;
Create (x0, y0, width, height: REAL) is body end;
add_box (x, y, width, height: REAL) is body end;
add_circle (x, y, radius: REAL) is body end;
add_to_selections (ashape: SHAPE) is body end;
clear_selections is body end;
cut_selections is body end;
group_selections: Group is body end;
move_selections (deltax, deltay: REAL) is body end;
redraw_all is body end;
select_item (x, y: REAL) is body end;
ungroup_selections is body end;
end -- class WINDOW
(feature) ( C++) , : export. Create ( C++) . .
Smalltalk : Smalltalk , . Smalltalk : (, , ) , , , , , .
Window Smalltalk :
class name Window
superclass Object
instance variables xmin, ymin, xmax, ymax: REAL
class methods
instantiating
createAt aPoint of Width: width ofHeigt: heigt
instance methods
adding shapes
addboxAt aPoint ofWidth: width ofHeigt: heigt
addCircleAt aPoint ofRadius: radius
refreshing window
redrawAll
manipulating selections
clearSelections
cutSelections
groupSelections
moveSelectionsBy: deltaPoint
selectItemAt: aPoint
ungroupSelections
private
addToSelections: aShape
Smalltalk Object, Smalltalk, Object. , , . . , private, . , . Smalltalk @, . x y ( ) aPoint, (x,y). (3,4) a Point @ :
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aPoint <- 3 @ 4
Eiffel ( (entity)) . , () , (void), .. . :
w: WINDOW
w, , . Eiffel : Create; , w:
w.Create (0.0, 0.0, 8.5, 11.0)
Create , . Create; , :
class WINDOW
...
feature
Create (x0, y0, width, height: REAL) is
do
xmin:= x0; ymin:= y0;
xmax:= x0 + width; ymax:= y0 + height;
end
...
end -- class WINDOW
Create, Clone.
Eiffel ( , delete C++). Forget , . , , , , ( ), .
Smalltalk . . . new, Object ( Smalltalk Object). , ( ) :
w <- Window new
new . ( ):
w <- Window createAt: 0 @ 0 ofWidth: 8.5 ofHeight: 11.0
:
class name Window
...
class methods
createAt: aPoint ofWidth: width ofHeigt: heigt
| w |
w <- self new.
w initialize: aPoint ofWidth: width ofHeigt: heigt.
instance methods
initialize: aPoint ofWidth: width ofHeigt: heigt.
xmin <- aPoint x.
ymin <- aPoint y.
xmax <- xmin + width.
ymax <- ymin + height
|
|
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, . initialize
Eiffel (routines). , (REAL, INTEGER, BOOLEAN, CHARACTER) , . ( Create, Clone Forget), . , , .
Eiffel , C++, '.' Eiffel '->' C++:
local
aShape: SHAPE;
dx, dy: REAL
do
...
aShape.move (dx, dy);
end
Eiffel . x y SHAPE:
move (deltax, deltay: REAL) is
-- move a shape by delta
do
x = x + deltax;
y = y + deltay
end
Eiffel Current, ( this C++ self Smalltalk). :
move (deltax, deltay: REAL) is
-- move a shape by delta
do
Current.x = Current.x + deltax;
Current.y = Current.y + deltay
end
Smalltalk ; , . , . (), ( ). . ( ) :
aShape moveDelta: aPoint
:
class name Shape
instance variables
x y
instance methods
moveDelta: aPoint
x <- x + aPoint x
y <- y + aPoint y
( Smalltalk (instance variables)).
, Smalltalk - self, ( ).
Eiffel inherit:
class ITEM
export
cut, move, pick, ungroup
feature
cut is deferred end;
move (deltax, deltay: REAL) is deferred end;
pick (x, y: REAL): BOOLEAN is deferred end;
ungroup () is deferred end
class SHAPE
export
cut, draw, erase, move, pick, ungroup, write
inherit ITEM
feature
* x, y: REAL;
cut is <body> end;
draw is <body> end;
erase is <body> end;
move (deltax, deltay: REAL) is <body> end;
pick (x, y: REAL): BOOLEAN is <body> end;
ungroup is <body> end;
write (acolor: COLOR) is deferred end;
end
classrBOX
export pick, write
inherit SHAPE redefine pick, write
feature
width, height: REAL;
Create (x0, y0, width0, height0:*REAL) is <body> end;
pick (x, y: REAL): BOOLEAN is <body> end;
write (acolor: COLOR) is <body> end
end
class CIRCLE
export pick, write
inherit SHAPE redefine pick, write
feature
radius: REAL;
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Create (x0, y0, radius0: REAL) is <body> end;
pick (x, y: REAL): BOOLEAN is <body> end;
write (acolor: COLOR) is <body> end
end
deferred; . redefine.
Smalltalk Item, Shape, Box Circle Shape :
class name Item
superclass Object
class name Shape
superclass Item
instance variables
x
y
instance methods
cut
draw
erase
move: aPoint
ungroup
class name Box
superclass Shape
instance variables
width
height
instance methods
pick: aPoint
write: aColor
class methods
createAt: aPoint width: widthSize length: lengthSize
class name Circle
superclass Shape
instance variables
radius
instance methods
pick: aPoint
write: aColor
class methods
createAt: aPoint radius: radiusSize
. . .
Eiffel , C++. ( (generic)) ( , ). Eiffel LINKED_LIST, ITEM GROUP:
class ITEM
export
get_group
-- GROUP
set_group(GROUP), forget_group(GROUP)
feature
get_group: GROUP is
do
Result:= mygroup
end;
set_group(g:GROUP) is
do
mygroup:= g
end;
forget_group is
do
forget(mygroup)
end;
end --ITEM
class GROUP
export
add_item, remove_item, get_items
inherit ITEM
feature
items: LINKED_LIST[ITEM]; --
Create is
do
items.Create
end;
add_item(value:ITEM) is
do
items.finish;
items.insert_right(value);
value.set_group(Current)
end;
remove_item(value:ITEM) is
do
items.search(value,l);
items.delete;
value.forget_group
end;
get_items(number:INTEGER):ITEM is
do
Result:= items
end;
end --GROUP
Eiffel . GROUP set_group forget_group ITEM. , ITEM GROUP.
forget Eiffel ; , , , .
Smalltalk . , (Item) , (Group), Set:
class name Item
superclass Object
class name Shape
superclass Item
instance variables
group
instance methods
cut
draw
erase
move: aPoint
ungroup
--
getGroup
group
--
putGroup: aGroup
group <- aGroup
class name Group
superclass Item
instance variables
items
class methods
new
|((super new)putItems:(Set new))
|
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instance methods
pick: aPoint
write: aColor
addItem: anItem
items add: anItem.
anItem putGroup: self
removeItem
items remove: anItem.
anItem putGroup: nil
getItems
|items copy
--
putItems: aSet
items <- aSet
, Smalltalk , , : , putGroup:, . , , , , ; , , Smalltalk , .
