COMP2310 - Week 1 - Ada fundamentals

Notes

Header files -> Used to define program specifications or compilation units are stored in .ads files

Implementation files -> Contain the executable code in .adb files which contain the implementation.

Note that the .ads files can be created first and used to check program types and syntax before it is actually implemented within the .adb files.

The with keyword is similar to the include in C/C++ or import in Python and Java.

The package name itself can be ommited by using the use keyword. Similar to the using <namespace> in C/C++ or import in Java.

with Ada.Text_IO; 

procedure Greet is
    
begin
    Ada.Text_IO.Put_Line ("Hello, World!");
end Greet;

with Ada.Text_IO; use Ada.Text_IO;

procedure Greet is
    
begin
    Put_Line ("Hello, World!");
end Greet;

Package

Java packages is used as a namespace for classes. In Ada it is often a compilation unit.

package Name is
   -- public declarations 
private
   -- private declarations
end Name;

package body Name is
   -- implementation 
end Name;

private -> Allows for use available for use while hiding the actual implementation.

record -> Ada's C/C++ struct whose fields are only visible to its package and not to the caller.

• Caller can refer to objects of that type, but not change the contents directly.

Introduction

with Ada.Text_IO;

procedure Greet is
    
begin
    Ada.Text_IO.Put_Line ("Hello, World!");
end Greet;

procedure -> Similar to a void function in C/C++ or Java.