Introduction to Ada Language

Ada is a programming language designed for large, long-lived applications where reliability and efficiency are essential.

• Humans make mistakes.

• Ada was designed to help us find mistakes.

We read programs more times than we write:

• Ada was designed for ease of reading

• An Ada program typically requires more typing than curly brace languages.

Ada Versions:

• Ada 83       (1983)

• Ada 95       (1995)

• Ada 2005  (2005)

• Ada 2012  (2012)

http://www.adacore.com/adaanswers/about/ada-comparison-chart

Why ‘Ada’ succeed where C fails?

No. #1 Reason: Modelling of scalar quantities

• Strong typing

• Run-time range checking

The adherence to strong typing allows detection of many common software errors (wrong parameters, range violations, invalid references, mismatched types, etc.) either during compile-time, or otherwise during run-time.

Other Reasons:

• Named parameter association.

• Arrays whose indices do not start at zero.

• High level abstractions for modelling device registers

• Record types

• Enumeration types

• High level of abstraction for tasking

• Interfaces to other programming languages like C, COBAL, etc.

• Compilation model

• Obsolete units are detected.

few Ada Compilers:

• GNAT (GNO Ada Translator)

• GPS (GNAT Processing Studio)   (V6.0.1)

• Irvine Cross Compiler (ICC) Ada

Ada Keywords:

There are 73 reserved keywords in Ada that may not be used as identifiers, and these are:

Ada Data Types:

C laguage basic data types: int, char, float, double

Ada language basic data types: integer, character, float, boolean

Ada Operators:

//constant

#include<stdio.h>

int main(void)

{

const int n = 10;

n = 20; //error

printf("n=%d\n", n);

return 0;

}

with Ada.Text_IO;

with Ada.Integer_Text_IO;

use Ada.Text_IO;

use Ada.Integer_Text_IO;

procedure Hello is

    n : constant integer := 10;

begin

  n := 20; -- error

  put(n);

end Hello;