I know this is not how to do things in here but i need some help with code. I need to make a RPN calc in ada that instantiate a couple packages and they are below. Please help i need help creating rpn.adb and not sure how to implement some of the other things below.
Thanks
stackpkg.adb
-- This is the generic implementation for a stack abstract data type.
package body StackPkg is
function IsEmpty (S : Stack) return Boolean is
begin
return S.Top = 0;
end IsEmpty;
...
procedure Push (Item : ItemType; S : in out Stack) is
begin
if IsFull (S) then
raise Stack_Full;
else
S.Top := S.Top + 1;
S.Elements(S.Top) := Item;
end if;
end Push;
...
end StackPkg;Stakcpkg.ads
-- This is the generic specification for a stack abstract data type.
-- Usage: Put these lines in the client (in the appropriate place):
-- with StackPkg; -- this statement precedes client procedure declaration
--
-- -- the next 2 statements go inside the client procedure
-- -- the next 2 statements go after MyType is declared
-- package MyStkPkg is new StackPkg(Size => 100; ItemType => MyType);
-- use MyStkPkg;
generic -- Generic parameters are declared here
Size : Positive; -- Size of stack to create
type ItemType is private; -- Type of elements that stack will contain
package StackPkg is
type Stack is limited private;
Stack_Empty: exception; -- Raised if do top or pop on an empty stack
Stack_Full : exception; -- Raised if push onto full stack
-- Determine if stack is empty or full
function isEmpty (s : Stack) return Boolean;
function isFull (s : Stack) return Boolean;
-- Put element Item onto Stack s
procedure push (item : ItemType; s : in out Stack);
-- Remove an element from Stack s
procedure pop (s : in out Stack);
-- Return top element from Stack s
function top (s : Stack) return ItemType;
private
type StackElements is array(1 .. Size) of ItemType;
type Stack is record
Elements : StackElements;
Top : Natural := 0;
end record;
end StackPkg;bignum.adb
-- This is the implementation for the BigNum abstract data type, which supports
-- arithmetic with VERY LARGE natural values. The operations provided
-- work as one would expect for natural numbers.
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
package body BigNumPkg is
-- Currently the implementation uses a base 10 system for
-- storing numbers and performing arithmetic operations.
--
InternalBase : constant Positive := 10;
-- This is a stub routine
-- You are to complete the implementation of this routine
function toString(X: BigNum) return String is
begin
return "";
end toString;
function "<" (X, Y : BigNum) return Boolean is
begin
for I in 0..Size-1 loop
if X(I) < Y(I) then
return True;
elsif X(I) > Y(I) then
return False;
end if;
end loop;
return False;
end "<";
function ">" (X, Y : BigNum) return Boolean is
begin
return not (X < Y or X = Y);
end ">";
function "<=" (X, Y : BigNum) return Boolean is
begin
return X = Y or X < Y;
end "<=";
function ">=" (X, Y : BigNum) return Boolean is
begin
return not (X < Y);
-- return Standard.">="(X, Y); -- Causes error on intel platform
end ">=";
-- To add two numbers, start in the right most part of the two
-- arrays and add column by column working toward the left. The
-- value of carry indicates how much of a previous column's value
-- should be carried forward to the next column's.
--
function "+" (X, Y : BigNum) return BigNum is
Carry : Natural := 0;
Sum : Integer;
Result : BigNum := (others => 0);
begin
for I in reverse 0..Size-1 loop
Sum := Carry + X(I) + Y(I);
-- Determine the amount of carry.
if Sum >= InternalBase then
Sum := Sum - InternalBase;
Carry := 1;
else
Carry := 0;
end if;
Result(I) := Sum;
end loop;
-- The result is too big if the left-most column gave
-- a carry.
if Carry > 0 then
raise BigNumOverFlow;
end if;
return Result;
end "+";
-- Currently implemented as repeated addition. This make "*" slow,
-- but at least the result is correct. :-)
--
function "*" (X, Y : BigNum) return BigNum is
Count, Result : BigNum := Zero;
begin
while Count /= Y loop
Count := Count + One;
Result := Result + X;
end loop;
return Result;
end "*";
-- Skips leading whitespace (spaces, tabs, end of lines) before
-- the data to be read.
--
procedure Get (Item : out BigNum) is
Letter : Character;
LineEnd : Boolean;
LastI : Natural := 0;
begin
-- Skip leading whitespace
loop
if End_Of_File then
raise DATA_ERROR;
elsif End_Of_Line then
Skip_Line;
else
Look_Ahead(Letter, LineEnd);
-- exit if find a digit
exit when Letter in '0'..'9';
-- Original version skipped leading zeros, as follows:
-- exit when Letter in '1'..'9';
Get(Letter);
if Letter /= ' ' and Letter /= ASCII.HT
and Letter /= '0' then
raise DATA_ERROR;
end if;
end if;
end loop;
-- Read in digits of number
for I in 0..Size-1 loop
exit when End_Of_Line;
Look_Ahead(Letter, LineEnd);
exit when LineEnd;
exit when Letter not in '0'..'9';
Get(Item(I), Width => 1);
LastI := I;
end loop;
-- If there's still more digits, then raise DATA_ERROR.
Look_Ahead(Letter, LineEnd);
if Letter in '0'..'9' then
raise DATA_ERROR;
end if;
-- Shift digits to the left within the array
for I in reverse 0..LastI loop
Item(I+Size-1-LastI) := Item(I);
end loop;
for I in 0..Size-2-LastI loop
Item(I) := 0;
end loop;
end Get;
-- Writes a BigNum to the output, padding with leading spaces
-- if the width given is larger than the length of the number
-- (leading zeros are not printed).
--
procedure Put (Item : BigNum; Width : Natural := 1) is
First : Integer := Size-1;
begin
-- Determine where the first digit of the number is,
-- and thus the length of the number.
for I in 0..Size-1 loop
if Item(I) /= 0 then
First := I;
exit;
end if;
end loop;
-- Put any leading blanks that are necessary.
for I in Size-First+1..Width loop
Put(' ');
end loop;
-- Write out the digits of the number.
for I in First..Size-1 loop
Put(Item(I), Width => 1);
end loop;
end Put;
end BigNumPkg;bignum.ads
-- This is the interface for the BigNum abstract data type, which supports
-- arithmetic with VERY LARGE natural values. The operations provided
-- work as one would expect for natural numbers.
with Ada.Text_IO; use Ada.Text_IO;
package BigNumPkg is
type BigNum is private;
Zero : constant BigNum;
One : constant BigNum;
BigNumOverFlow : exception;
function toString(X: BigNum) return String;
function "<" (X, Y : BigNum) return Boolean;
function ">" (X, Y : BigNum) return Boolean;
function "<=" (X, Y : BigNum) return Boolean;
function ">=" (X, Y : BigNum) return Boolean;
function "+" (X, Y : BigNum) return BigNum;
function "*" (X, Y : BigNum) return BigNum;
procedure Get (Item : out BigNum);
procedure Put (Item : BigNum; Width : Natural := 1);
private
Size : constant Positive := 50;
type BigNum is array(0..Size-1) of Integer;
Zero : constant BigNum := (others => 0);
One : constant BigNum := (Size-1 => 1, others => 0);
end BigNumPkg;