Program Structure
In this chapter we will learn about using many source code files in the same project.
Source Code File Sections
Each source code file may contains the next sections (in the same order).
Source Code File Sections |
---|
Load Files |
Statements and Global Variables |
Functions |
Packages and Classes |
The application maybe one or more of files.
Using Many Source Code Files
To include another source file in the project, just use the load command.
Syntax:
Load "filename.ring"
Note
The Load command is executed directly by the compiler in the parsing stage
Tip
if you don’t know the file name until the runtime, or you need to use functions to get the file path, just use eval().
Example:
# File : Start.ring
Load "sub.ring"
sayhello("Mahmoud")
# File : sub.ring
func sayhello cName
see "Hello " + cName + nl
Load Package
Using the ‘load’ command we can use many ring source files in the same project
But all of these files will share the same global scope
We have also the “Load Package” command
Using “Load Package” we can load a library (*.ring file) in new global scope
This is very useful to create libraries that avoid conflicts in global variables
Example:
File: loadpackage.ring
x = 100
? "Hello, World!"
load package "testloadpackage.ring"
? x
test()
File: testloadpackage.ring
? "Hello from testloadpackage.ring"
x = 1000
test()
func test
? x
Output:
Hello, World!
Hello from testloadpackage.ring
1000
100
1000
Load Again
Ring 1.12 comes with the Load Again command
Using this command we can load the Ring source file which contains constants more than one time.
This is useful when using Ring source files for translations through global constants.
Example:
The next function is part from a project which support Arabic and English languages
The files english.ring and arabic.ring contains constants for translation
One of these files is loaded in the start of the program
Loading the same file again using the (Load) command is not possible
Because the (Load) command load the same source file only for the first time and ignore next times.
So we have to use the (Load Again) command.
Where we can use these files again during the runtime as in the next code
func setLang nLanguage
if C_ENV_DEFAULT_LANG = nLanguage
return
ok
C_ENV_DEFAULT_LANG = nLanguage
# Change the language
switch nLanguage
on C_TRANSLATION_ENGLISH
load again "translation/english.ring"
on C_TRANSLATION_ARABIC
load again "translation/arabic.ring"
off