Data Structures Lab 3 – Containers Fall 2018 Burris

Data Structures代写 Most modern programming languages offer a “container” class for the convenience of users. Data Structures Lab 3

Data Structures代写
Data Structures代写

Due:  Friday November 9th prior to the start of class:

Submission:  For all options the results should appear first followed by the complete code!      Data Structures代写

Most modern programming languages offer a “container” class for the convenience of users.Data Structures代写

 Containers are typically inefficient with respect to CPU time and memory allocation compared to static types.  They may however offer great convenience for the developer.  Commonly offered container classes include one for constrained objects and a second for unconstrained objects.  These classes typically are further refined to incorporate containers termed “sequence” and “associative.”  Sequence classes hold sequences of related items.  Associative classes associate a key with each element of the class then manipulate elements based on the keys.  You may not utilize container classes in any language for any lab during the semester unless the lab specifically states you must use the container class.  Ada provides the following container for “defined/constrained” classes:

a. Containers.Vectors

b. Containers.Doubly_lLinked_Lists

c. Containers.Hashed_Maps

d. Containers.Ordered_Maps

e. Containers.Hashed_Sets

f. Containers.Ordered_Sets

A similar group of classes/packages is provided for undefined/unconstrained types using similar names including Ada.Data Structures代写

Containers.Indefinite_Vectors with specialized generic procedures such as Ada.Containers.Generic_Array_Sort and Ada.Containers.Generic_Constrained_Sort.  The purpose of this lab is to develop the basic technology to implement (program) these capabilities in languages including Ada, C++, Java, Python and Smalltalk using more basic constructs.  Implementation of containers, complex numbers, etcetera using code placed in libraries extends the capabilities of languages.  This technique is widely used to extend programming language capabilities and convenience for modern languages.

“C” Option: Homogeneous (maximum grade is 70):        Data Structures代写

Hint: appendix 1, 2 and 3. For the “C” Option remove the generic in appendix 2, replace “item” with Integer and set max to a specific value like 20.  Appendix 3 is closest to the lab.  Appendix 6 is helpful if you need to pass functions or operator overloads.

Implement package/class Integer_Containers allowing the user to store a list of integers whose meaning is application dependent with respect to the user (a homogeneous list).  List must store elements in a doubly linked list (container) with a list head.  The following represents a list with 33 inserted first followed by 46 on the right side (front) of the head node.

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A container (package/class) definition would normally contain procedures and/or functions to insert at the head of the list,Data Structures代写

insert at the rear of the list, provide the number of items currently in the list, search for an item returning a pointer to it if found (null if not found), print the contents of the item given a pointer to the node containing the item and ask for the next item in the list traversing the list from the front to rear.  Finally, you must be able to delete a random item from the doubly linked list given its location (pointer to the item).  A partial package/class specification might include the following:

package Integer_Containers is

           type Integer_Container is private;

           type Integer_Node_Point is access Integer_Container;

           procedure InsertFront( list: in out Integer_Container, amt: in Integer, Success: Boolean);

           procedure InsertRear( list: in out Integer_Container, amt: in Integer, success: out Boolean);

           function listSize( list: in Integer_Container) return Integer;

           function findItem( list: in Integer_Container, aValue: Integer) return Integer_Node_point);

           procedure delete(list: in out: Integer_Container, Integer_NodePoint);

           -- Additional functions and procedures as needed.

private

           type Integer_Container is record

                      value: Integer;

                      next, previous: Integer_Pointer;

           end Integer_Container;

           -- rest of specification.

           end Integer_Containers;  -- followed by the body in another file

           --Main program

                        MyList: Integer_Container;  -- create an integer container as a doubly linked list.

Process all “C” option transactions in the order specified.          Data Structures代写

a. Insert 33 in front (right).

b. Insert 57 in front

c. Insert 85 at the rear (left).

d. Insert 95 at the front.

e. Print the contents of the list from front to rear.

f. Find and delete the node containing 57.

g. Find and delete the node containing 33.

h. Find and delete the node containing 33.

i. Insert 22 in front.

j. Delete the node containing 95.

k. Print the contents of the list.

“B” Option – Homogeneous (maximum grade is 80):

Hint: Appendix 1,2, 3.  Appendix 6 is helpful if you need to pass functions or operator overloads.     Data Structures代写

You need not do the “C” option.  Write a generic/template package/class List_Package allowing the user the ability to store any programmer defined type in a doubly linked list with the operations defined in the “C” option.  Use a list head.  You will probably wish to provide an overload for the “=” operator as a generic parameter.  Implement the package/class List_Package allowing for any user defined in a doubly linked list.  Each entry in the list other than the head node may be used to store a user defined transaction.  Data fields in the head node may be used or ignored by the implementer.  The basic package/class definition will contain at least the following methods:

generic

           type ItemsType is private;

package List_Package is

           -- Methods for previous grading option

           --   See sample specification/code for similar application below inCompStacg.

end List_Package – followed by the body in another file

-- main program

with List_Package;

procedure MainLine is

           type ItemType is ( Shoes, Kites, Jacks, Food);

           currentItem: ItemType;

           price: Float;

           amt: Integer;

           type InventoryItem is record

           itemName: ItemType; unitPrice: Float; inStock: Integer;

           end InventoryItem;

           temp, theItem: InventoryItem;

package InventoryList is new List_Package (InventoryItem); use InventoryList;

Process the following transactions in the specified order after creating homogeneous containers for cars and planes (two separate lists).  Data Structures代写

You may use the code for cars and planes used in the examples below if desired.  Place the cars and planes in the correct lists.

a. Insert a Ford with 4 doors at the rear.

b. Insert a Ford with 2 doors at the front.

c. Insert a GMC with 2 doors at the rear.

d. Insert a RAM with 2 doors at the rear.

e. Insert a Chevy with 3 doors at the front.

f. Print the number of items in the list.

g. Print the contents of the list (front to rear).

h. Find and delete the first Ford in the list (search front to rear).

i. Print the number of items in the list.

j. Print the contents of the list (front to rear).

k. Insert a plane with 3 doors and 6 engines by Boeing at the front.

l. Insert a plane with 2 doors and 1 engines by Piper at the front.

m. Insert a plane with 4 doors and 4 engines by Cessna at the front.

n. Print the list.

 

Hint:  You do not need the “abstract stack (inheritance from a common ancestor) to create the car and plane types in appendix 5.  You may use my code for cars and planes in your code.

 “A” Option: Heterogeneous Container using Inheritance (maximum grade is 95).  Appendix 6 is helpful if you need to pass functions or operator overloads.Data Structures代写

 

Hint: Appendix 1,4 and 5 for all “A” Options.

You need not do the “C” or “B” options.  Rather implement a single package/class using inheritance to allow multiple data types/objects in a heterogeneous list.  Use this package/class to implement a single doubly linked list and process all “B” Option transactions placing the cars and planes in a single container (list).

A sample list with one plane and one car follows:

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An example of the empty list follows:

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“A+” Option: Heterogeneous Container using Inheritance (maximum grade is 105):

Complete the “A” option.  Allow at least one task to place items in the list and a second task to remove items from the list.

“A Super +” Option: Heterogeneous Container using Inheritance (maximum grade is 115):

Complete the “A” option.  Allow multiple tasks to place items in the list and  multiple tasks to remove items from the list preventing RACE conditions!

Appendix 1: For all options.          Data Structures代写

In most industries employee records (inventory records etcetera) appear 20 or more times in applications.  Rather than define them in every application it is convenient do define them once then utilize the same definition for the abstraction in every application.   Not only is this convenient but increases sharing, consistency across applications, and ease of update for all applications, The following class illustrates the sharing concept for dates.

         -- in file CompStk1.ads

         -- Exports IntIO, MonthName, MonthNmaeIO, Date and PrintDate.

          with Ada.Text_IO; use Ada.Text_IO;

          package CompStk1 is

            package IntIO is new Ada.Text_IO.Integer_IO(Integer);

            use IntIO;

            type MonthName is (Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep,

                                        Oct, Nov, Dec);  -- Enumeration type.

         package MonthNameIO is new – Ada generates i/O routines.

                   Ada.Text_IO.Enumeration_IO(MonthName);

  use MonthNameIO;

  type Date is record

    Month: MonthName;

    Day: Integer range 1..31;  -- Limits range.

    Year: Integer;                    -- No limit on range.

  end record;

  procedure PrintDate(aDate: Date);

end CompStk1;

--in file CompStk1.adb

package body CompStk1 is

  procedure PrintDate(aDate: Date) is

   begin

    put("mmm/dd/yyyy is "); put(aDate.Month);put("/");

    put(aDate.Day,2); put("/"); put(aDate.Year,4);

  end PrintDate;

end CompStk1;

Appendix 2: For “C” Option          Data Structures代写

Sample homogeneous stack for intrinsic data types and programmer data type including task types.

generic                       — in file Gstack.ads                        

max:integer;             — size of stack

type item is private;  — type to stack

package gstack is

               procedure push(x: in item);

               procedure pop(x: out item);

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end gstack;

%%%%%%%%%%%%%%%%%%%%%%%%%%

package body gstack is   — in file Gstack.adb

               s:array(1..max) of item;  — allocate in stack.

               top: integer range 0..max;

               procedure push(x: in item) is

               begin

                  top := top + 1;   s(top) := x;

               end push;

               procedure pop(x: out item ) is

               begin

                 x := s(top);    top := top – 1;

               end pop;

begin

               top := 0; –initialize top of stack to empty

end gstack;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

with Ada.Text_IO; use Ada.Text_IO;  — in file Gusestac.adb

with gstack;   — generic stack defined in gstack10.ads /.adb

procedure genstack is

    package IIO is new Ada.Text_IO.Integer_IO(integer); use IIO;

        package integer_stack is new gstack(100,integer);

        use integer_stack;

        m: integer;

begin

        for i in 1..4 loop

              put(“enter an integer “);    get(m);    push(m);

        end loop;  for i in 1..4 loop put(“result of pop “);    pop(m);    put(m);    new_line;

        end loop;

end genstack;

 

— Consider adding:  package intStk is new gstack(10,integer); use intStk;— Now push(m) will result in a compile time error as “Push” cannot be

–uniquely determined from the context.  Use intStk.push(m) or

–integer_stack.push(m), the full object oriented notation.

Now consider using the “date” type.  A skeleton follows.

with Ada.Text_IO; use Ada.Text_IO;

with gstack;;

with CompStkg;  use CompStkg;

procedure UCmpStkg is  — in file UCmpStkg

    stackSize: integer := 15;

package DateStack is new gstack(stackSize, Date);

use DateStack;

— rest followed by access, shown 2 ways

    push(aDate);  –if stack is clearly identifiable (unique0 or to specify using

    DateStack.push( aDate );   — DateStac if there are multiple date stacks.

Appendix 3: Stack implemented as a linked list.       Data Structures代写

The following creates a homogeneous stack using a linked list.  The “C” option does not require the generic as each stack only stores a specific predefined type.  The generic allows for the user to store any intrinsic or user defined type (including tasks, protected types, etc.).  Replacing “MyType with “integer,” Float,” Character, Date etcetera creates the desired stack type.

generic   -- in file CompStkg.ads

   type MyType is private;

package CompStkg is


   procedure Push(X: MyType);

   function  Pop return MyType;  -- Note parenthesis are not required if there are no parameters.

private

type Node;  -- Avoid recursive definition.

type NodePtr is access Node;  -- Define pointer type to Node.



type Node is record  -- Allocated in heap at run time.

  MyData: MyType;

  Next: NodePtr;

 end record;

end CompStkg;



with Ada.Unchecked_Deallocation;  -- in file CompStkg.adb

package body CompStkg is

-- Provide opportunity for garbage collection and reuse of Nodes.

  function free is new Ada.Unchecked_Deallocation(Node, NodePtr);  -- reclaim heap storage.

  Head, pt: NodePtr := null;  -- Ada actually sets all pointers to null when they are declared.


  procedure Push(X: MyType) is

  begin                        -- No check for overflow.

   Head := new Node'(X, Head);  -- Allocated from returned memory, heap is none returned.

  end Push;  -- Most languages return Head = null if out of storage.
 

  function  Pop return MyType is

   X: MyType;

  begin

   X := Head.MyData;          -- No check for underflow.

    pt := Head;

   Head := Head.Next;

   free(pt);   -- Memory hemorraging occurs if forgotten.

   return X;

  end Pop;


end CompStkg;
—  Example of programming by “Composition” (bottom-up, creating whole from parts)

—  as opposed to programming by “Classification”

—  (top-down) better known as the use of inheritance. Data Structures代写

with Ada.Text_IO; use Ada.Text_IO;

with CompStk1; use CompStk1;

with CompStkg;

procedure UCmpStkg is  — in file UCmpStkg

  package CharStack is new CompStkg(character);

  use CharStack;

  package DateStack is new CompStkg(CompStk1.Date);

  use DateStack;

  Char: Character;

  ADate: Date;

begin

  Push(‘A’);  Push(‘B’);  Push(‘C’);

  put(pop);   put(Pop);   put(Pop);  new_line(2);

  Push((Jan, 15, 1992)); Push((Mar, 24, 1994));

  Push((Jun, 12, 1999));

  ADate := Pop;  PrintDate(ADate); new_line;

  Adate := Pop;  PrintDate(Adate); new_line;

  Adate := Pop;  PrintDate(ADate); new_line;

end;

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Appendix 4: “B/A” Option to Implement Containers.       Data Structures代写

The preceding examples are limited to stacks containing a single data type, i.e., “homogeneous” lists.  Industrial grade applications may find it necessary to store more than one type/class item in the container.  The assumption is the “heterogeneous” items will have similar operations on the data.  The software will select the appropriate version of the method for the user selected operation, i.e., polymorphism.  Ada is polymorphic by default.  We start with an example of homogeneous inheritance (tagged types) then expand the example to allow heterogeneous data types.  The secret in most object oriented languages (Java, C++, SamllTalk, Ada, etc.) is for all children to be derived from a common parent type.  Similar operations (methods, procedures, functions) on the data type employ polymorphic methods to implement the behavior for each desired type.  The container for the parent type implies the ability to include children derived from the parent.

— Creation of a “cube” type from a “rectangle” type using inheritance.

–in file taged1.adb

with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;

procedure taged1 is

  type Rectangle is tagged  — tagged allows inheritance

    record

      length:   Integer;

      width:    Integer;

    end record;

  function Size(r: in Rectangle) return Integer is  — “intrinsic” method

begin   return r.length * r.width;   end Size;

— create a cube by inheriting from Rectangle.

  type Cube is new Rectangle with – create cube using inheritance

          record     height:   Integer;    end record;

— Cube inherits fields length, width, and function Size.

— This size may be redefined as:

  function Size(c: Cube) return Integer is  — intrinsic function

begin

return Size( Rectangle( C ) ) * C.height;  — cast “Cube” as a rectangle.

    end Size;

— Note the type conversion “Rectangle(c)” so that the inherited

— function Size for Rectangle (overload) can be used.

  rect1:  Rectangle := (6,10);

  cube1:  Cube := (length => 6, width => 10, height => 20);

begin

    put( Size( rect1 ) );      put( Size( cube1 ) );

    rect1 := Rectangle( cube1 );   cube1 := ( rect1 with 20 );

end taged1;

— User-written subprograms are classified as primitive operations

— if they are declared in the same package specification as the

— type and have the type as a parameter or result. Derived types

— inherit all primitive operations that belong to the parent type.

Appendix 5: “B/A” Heterogenous Abstract Type taking advantage of inheritance.   Data Structures代写

Ada allows definition/implementation of related types/classes in the same file.

This example uses the object notation for methods as follows to creating intrinsic methods for a package:

“procedures:”  <method-name> (<object>, <parameters>)

“functions::” <function-name>( <object>, <parameters>)

                       return <return-type>

-- Programing by  “Classification” (top-down) as opposed to

-- composition by “Composition” (bottom-up).



--  In file AbstStck.ads,  Creation of abstract stack.

package AbstStck is

  type AbstractStack is limited private;

  type AbstractStackElement is tagged private;

  type AbstractStackElementPtr is

     access all AbstractStackElement’Class;

     –Allows access to AbstractStackElement and any class inheriting

     –(created from using inheritance) from AbstractStackElement.

  procedure Push(Stack: access AbstractStack; Y: in AbstractStackElementPtr);

  function   Pop(Stack: access AbstractStack) return AbstractStackElementPtr;

  function  StackSize(Stack: AbstractStack) return integer;

— function “=” (aNode: AbstractStackElementPtr,

                     valueToCompare: genreric-parameter-for-comparison) return Bollean;

private

  type AbstractStackElement is tagged – Allow for heterogeneous

     record                                               — stacks via inheritance.

       Next: AbstractStackElementPtr;

     end record;

  type AbstractStack is limited

   record

     Count: integer := 0;  — used to track the number of items in stack.

       Top: AbstractStackElementPtr := null;

  end record;

end AbstStck;

— In file AbstStck.adb

package body AbstStck is

procedure Push(Stack: access AbstractStack; Y: in AbstractStackElementPtr) is

   Pt: AbstractStackElementPtr;

begin

   Y.Next := Stack.Top;  Stack.Top := Y;  Stack.Count := Stack.Count + 1;

end Push;

function Pop(Stack: access AbstractStack) return AbstractStackElementPtr is

   Pt: AbstractStackElementPtr;

begin

   if Stack.Top = null then — Check for underflow.

       return null;

   end if;

   Stack.Count := Stack.Count – 1;

   Pt := Stack.Top;  Stack.Top := Stack.Top.Next;  — Pop stack, note hemmoraging.

  return Pt;    — Storage should be returned to an available storage list for applications

  end Pop;     — with high activity or executing for extended periods of time.

  function StackSize(Stack: AbstractStack) return integer is

  begin  return Stack.Count;  end StackSize;

end AbstStck;

Creation/use of a Car type used with a stack.

— in file MakeCar.ads

with AbstStck;

package MakeCar is

  type String4 is new String(1..4);

  type Car is new AbstStck.AbstractStackElement with record

     NumDoors:  integer;

     Manufacturer: String4 := “GMC “;  — Sample default value.

  end record;

  procedure AssignNumDoors(aCar: in out Car; N: in integer);

  procedure AssignManufacturer(aCar: in out Car; Manu: in String4);

  procedure PrintNumDoors(aCar: in Car);

  procedure PrintManufacturer(aCar: in Car);

  procedure IdentifyVehicle(aCar: in Car);

end MakeCar;

— in file MakeCar.adb

with Ada.Text_IO; use Ada.Text_io;

with AbstStck;

package body MakeCar is

  package IntIO is new Ada.Text_IO.Integer_IO(Integer);  use IntIO;

  procedure AssignNumDoors(aCar: in out Car; N: in integer) is

  begin aCar.NumDoors := N; end AssignNumDoors;

  procedure AssignManufacturer(aCar: in out Car; Manu: in String4) is

  begin aCar.Manufacturer := Manu; end AssignManufacturer;

  procedure PrintNumDoors(aCar: in Car) is

  begin put(“Num doors = “); put(aCar.NumDoors); new_line; end PrintNumDoors;

  procedure PrintString4(PrtStr: String4) is

  begin for I in 1.. 4 loop

      put(PrtStr(I));

  end loop; end PrintString4;

  procedure PrintManufacturer(aCar: in Car) is

  begin put(“Manufacturer is “); PrintString4(aCar.Manufacturer); new_line; end;

  procedure IdentifyVehicle(aCar: in Car) is

  begin

      put(“Car with “); put(aCar.NumDoors, 4); put(” doors”);

      put(” made by “); PrintString4(aCar.Manufacturer); new_line;

   end IdentifyVehicle;

end MakeCar;

–in file UAbstStc.adb: place cars in the stack.

with Ada.Text_IO; use Ada.Text_io;

with AbstStck; use AbstStck;

with MakeCar; use MakeCar;

procedure UAbstStc is

  type Stack_Ptr is access AbstractStack;

  CarStack:  Stack_Ptr := new AbstractStack;

  StackPoint: Stack_Ptr;

  NewCar, CarPt: AbstractStackElementPtr;

begin  –Create 1st car.

  NewCar := new Car'(AbstractStackElement with 4, “Ford”); –Heap allocation

  push(CarStack, NewCar);

  NewCar := new Car;  — Create 2nd car.

  AssignNumDoors(Car’Class(NewCar.All), 2);

  AssignManufacturer(Car’Class(NewCar.all), “Chev”);

  push(CarStack, NewCar);

  NewCar := new Car;  — Create 3rd car.

  AssignNumDoors(Car’Class(NewCar.All), 2);

  — Default manufacturer to “GMC “.

  push(CarStack, NewCar);

  for I in 1..StackSize(CarStack.all) loop

     CarPt := pop(CarStack);

     PrintManufacturer(Car’Class(CarPt.All));

     PrintNumDoors(Car’Class(CarPt.All));

     new_line;

  end loop;

end UAbstStc;

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—  file MakePlane.ads:  Create planes for use with heterogeneous container.

with AbstStck;

package MakePlane is

  type String8 is new String(1..8);

  type Plane is new AbstStck.AbstractStackElement with record

     NumDoors:  integer;

    NumEngines:  integer;

    Manufacturer: String8 := “Boeing  “;

  end record;

  procedure AssignNumDoors(aPlane: in out Plane; N: in integer);

  procedure AssignManufacturer(aPlane: in out Plane; Manu: in String8);

  procedure AssignNumEngines(aPlane: in out Plane; NE: in integer);

  procedure PrintPlane(aPlane: in Plane);

  procedure IdentifyVehicle(aPlane: in Plane);

end MakePlane;

— In file MakePlane.adb

with Ada.Text_IO; use Ada.Text_io;  with AbstStck;

package body MakePlane is

  package IntIO is new Ada.Text_IO.Integer_IO(Integer);  use IntIO;


  procedure AssignNumDoors(aPlane: in out Plane; N: in integer) is

  begin aPlane.NumDoors := N; end AssignNumDoors;


  procedure AssignManufacturer(aPlane: in out Plane; Manu: in String8) is

  begin aPlane.Manufacturer := Manu; end AssignManufacturer;


  procedure AssignNumEngines(aPlane: in out Plane; NE: in integer) is

  begin aPlane.NumEngines := NE; end AssignNumEngines;


  procedure PrintString8(PrtStr: String8) is

  begin for I in 1..8 loop  put(PrtStr(I));   end loop; end PrintString8;


  procedure PrintPlane(aPlane: in Plane) is

  begin

    put("Num doors for plane = "); put(aPlane.NumDoors, 4); new_line;

    put("Number engines = "); put(aPlane.NumEngines); new_line;

    put("Manufacturer = "); PrintString8(aPlane.Manufacturer); new_line;

  end PrintPlane;


  procedure IdentifyVehicle(aPlane: in Plane) is

  begin

    put("Plane with "); put(aPlane.NumDoors, 4); put(" doors, ");

    put(aPlane.NumEngines, 4); put(" engines, made by ");

    PrintString8(aPlane.Manufacturer); new_line;

  end IdentifyVehicle;

end MakePlane;

Using heterogeneous stack with cars and planes in same stack.

with Ada.Text_IO; use Ada.Text_io;

with AbstStck; use AbstStck;

with MakeCar, MakePlane; use MakeCar, MakePlane;

procedure  UAbstSt2 is

  type Stack_Ptr is access AbstractStack;

  VehicleStack:  Stack_Ptr := new AbstractStack;

  StackPoint: Stack_Ptr;

  NewCar, CarPt, NewPlane, PlanePt, VehiclePt:

        AbstractStackElementPtr;

begin

  NewCar := new Car'(AbstractStackElement with 4, “Ford”);  — Heap allocation!

  push(VehicleStack, NewCar); — 1st car.

  NewPlane := new Plane'(AbstractStackElement with 2, 2, “Northrup”);  — in heap!

  push(VehicleStack, NewPlane);  –1st plane.

  for I in 1..StackSize(VehicleStack.all) loop

    VehiclePt := pop(VehicleStack);

    if VehiclePt.all in Car then  — ** Identify class of object at run time.

      IdentifyVehicle(Car’Class(VehiclePt.all));

   elsif VehiclePt.all in Plane then

      IdentifyVehicle(Plane’Class(VehiclePt.all));

  end if;

 new_line;

end loop;

end UAbstSt2;

7
7

 

 

 

 

 

 

 

 

 

**** Heterogeneous versus Homogeneous!

Appendix 6: Passing Functions and Operator Overloads          Data Structures代写

— In file GIOEX.ads.  Creates a rectangle with user defined data type for length and

— width.  Note that it is frequently desirable to pass methods including I/O routines

— for programmer defined data types.

— The following demonstrates how to pass I/O procedures to a generic package.

— The rectangle may also be used for inheritance if desired.

 

generic

    type MyType is private;

    with function “*”(X,Y: MyType) return MyType;

    with procedure Put(X: MyType);

package GIOEX is

  type Rectangle is tagged

    record

      Length:   MyType;

      Width:    MyType;

    end record;

  function Size(r: in Rectangle) return MyType;  — intrinsic functions

  function RectLength(r: in Rectangle) return MyType;

end GIOEX;

–in file GIOEX.adb

   with Ada.Text_IO; use Ada.Text_IO;  — Access restricted to body.

package body GIOEX is

  function Size(r: in Rectangle) return MyType is

  begin

     put(“The Size of the Rectangle with length “); put(r.Length);

     put(” and width “); put(r.Width);  put(” is “);

     put( r.Length * r.Width);  put(“!”); new_line(2);

     return r.Length * r.Width;

   end Size;

  function RectLength(r: in Rectangle) return MyType is

  begin

     put(“The length is “); put(r.Length);

     new_line;

     return r.Length;

   end;

end GIOEX;

— Sample program to show how to pass a programmer defined data type

—  and I/O methods to a generic.

— in file UGIOEX.adb

with GIOEX;

with Ada.Text_IO; — Use Ada.Text_IO;

procedure UGIOEX is

  package MyFloatIO is new Ada.Text_IO.Float_IO(Float);

  use MyFloatIO;

–The generic put statement format in Ada.Text_IO.Float_IO.

—  procedure Put( item: float;

—                 fore: Ada.Text_IO.field := 0;      — “0” means use minimum space.

—                 aft:  Ada.Text_IO.Field := 0;

—                 exp:  Ada.Text_IO.Field := 0

— );

—  Supply an overload for the generic written by the compiler in MyFloat_IO.

    procedure MyPut(X: Float) is

    begin    MyFloatIO.Put(X, 0, 0, 0);  end;

— Note that “*” is defined for the intrinsic type Float.

  package MyGIOEX is new GIOEX( Float, MyPut, “*”);

  use MyGIOEX;

  Rect1: Rectangle := (5.0, 6.0);  //Create class object using constructor!

  Len: Float;

begin

  Len := Size(Rect1);  Len := RectLength(Rect1);

end UGIOEX;

c:\>UGIOEX

The Size of the Rectangle with length 5.0 and width 6.0 is

30.0!    -- 3.00000E+01




The length is 5.0    --  5.00000E+00

— in file usegioex2.adb.  Use of Venus units for measurement.

— These operations are required for our human mission to Venus.

Sample overloading the “*” Operator

with Ada.Text_IO; use Ada.Text_io;

with GIOEX;

procedure UseGioex2 is

  package MyIntIO is new Ada.Text_IO.Integer_IO(Integer);

  package MyFloatIO is new Ada.Text_IO.Float_IO(Float);

    type VenusMeasure is record

        F1: Integer;

        F2: Float;

    end record;

— Define I/O for VenusMeasurement.

   procedure Put(v: VenusMeasure) is

   begin

      MyIntIO.put(v.F1);

      put(” “);

      MyFloatIO.put(v.F2);

      new_line;

   end;

— Define mutliplication for VenusMeasurement.

   function “*”(p1: VenusMeasure; p2: VenusMeasure)

return VenusMeasure is

      temp: VenusMeasure;

   begin

      temp.F1 := p1.F1 * p2.F1;

      temp.F2 := p1.F2 * p2.F2;

      return temp;

   end;

   package MyVenusRectangle

is new GIOEX(VenusMeasure, Put, *“);

   use MyVenusRectangle;

  width: VenusMeasure := ( 5, 5.5);

  height: VenusMeasure := (3, 2.4);

  Rect1: Rectangle := (width, height);  — Creates a rectangle using

                                                                     — Venus measurements.

  Ans: VenusMeasure;

begin

  Ans := Size( Rect1 );

end UseGIOEx2;

Data Structures代写
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