The Ring programming language version 1.5.4 book - Part 75 of 185

1. Ring Documentation, Release 1.5.4
62.8 Using the ‘else’ keyword as ‘other’ in switch statement
if you don’t like the ‘other’ keyword in switch statement Then you can use the ‘else’ keyword.
Also you can replace ‘else’ with ‘other’ in if statement.
i.e. ‘other’ keyword is the same as ‘else’ keyword.
Example:
x = 1
switch x
on 10
see "10" + nl
else
see "not 10" + nl
end
Output:
not 10
62.9 Using the ‘end’ keyword in different control structures
We can use the ‘end’ keyword to close different control structures
• If statement
• For loop
• Switch
• While
• Try-Catch
Example:
see "if statement.." + nl
x = 1
if x = 1
see "one" + nl
elseif x=2
see "two" + nl
elseif x=3
see "three" + nl
end
see "for loop.." + nl
for t = 1 to 10
see t
end
see nl
see "switch..." + nl
x = 1
switch x
on 1 see "one" + nl
on 2 see "two" + nl
end
62.8. Using the ‘else’ keyword as ‘other’ in switch statement 715

2. Ring Documentation, Release 1.5.4
see "try catch..." + nl
try
x = 1 / 0
catch
see "catching error" + nl
end
Output:
if statement..
one
for loop..
12345678910
switch...
one
try catch...
catching error
62.10 Using braces to start and end different control structures
We can use braces { } to start and end different control structures
• If statement
• For loop
• Switch
• While
• Try-Catch
Example:
see "if statement.." + nl
x = 1
if x = 1 {
see "one" + nl
elseif x=2
see "two" + nl
elseif x=3
see "three" + nl
}
see "for loop.." + nl
for t = 1 to 10 {
see t
}
see nl
see "switch..." + nl
x = 1
switch x {
on 1 see "one" + nl
on 2 see "two" + nl
}
see "try catch..." + nl
try {
62.10. Using braces to start and end different control structures 716

3. Ring Documentation, Release 1.5.4
x = 1 / 0
catch
see "catching error" + nl
}
Output:
if statement..
one
for loop..
12345678910
switch...
one
try catch...
catching error
62.11 Using ‘put’ and ‘get’ as ‘see’ and ‘give’
We can replace the ‘see’ keyword with the ‘put’ keyword.
Also we can replacew the ‘give’ keyword with the ‘get’ keyword.
Example:
put "Hello World" + nl
put "Enter Your Name ? " Get Name
Put "Hello " + Name
62.12 Using ‘case’ as ‘on’ in switch statements
We can replace the ‘on’ keyword with ‘case’ keyword in the switch statement.
Example (1) :
for x=1 to 10
switch x
case 1 put "one" + nl
case 2 put "two" + nl
case 3 put "thre" + nl
else put "else" + nl
end
end
Example (2) :
for x=1 to 10 {
switch x {
case 1 put "one" + nl
case 2 put "two" + nl
case 3 put "thre" + nl
else put "else" + nl
}
}
62.11. Using ‘put’ and ‘get’ as ‘see’ and ‘give’ 717

4. Ring Documentation, Release 1.5.4
62.13 Using ‘def’ as ‘func’ in functions/methods definition
We can use the ‘def’ keyword as the ‘func’ keyword to define functions and methods.
Example:
one() two()
def one put "one" + nl
def two put "two" + nl
62.14 Using braces { } in Packages/Classes/Functions
Example:
load "stdlib.ring"
import mypackage
new myclass {
myfunc()
}
package mypackage
{
class myclass
{
func myfunc
{
print("Hello, World!n")
}
}
}
62.15 Using ‘end’ keyword after Packages/Classes/Functions
Example:
import mypackage
new myclass {
myfunc()
}
package mypackage
class myclass
def myfunc
put "Hello, World!"
end
end
end
62.13. Using ‘def’ as ‘func’ in functions/methods definition 718

5. Ring Documentation, Release 1.5.4
62.16 Using ‘endpackage’/’endclass’/’endfunc’ keywords after Pack-
ages/Classes/Functions
Example:
import mypackage
new myclass { myfunc() }
package mypackage
class myclass
func myfunc
see "welcome" + nl
endfunc
endclass
endpackage
62.16. Using ‘endpackage’/’endclass’/’endfunc’ keywords after Packages/Classes/Functions 719

6. CHAPTER
SIXTYTHREE
INTRODUCTION TO THE TYPE HINTS LIBRARY
In this chapter we will learn about the Type Hints Library
63.1 Why Type Hints?
Using this library we can add the type information to the source code which will be very useful for tools like
• Code Editors
• Static-Analysis
Note: Ring is a dynamic language, No type checking will be done by the compiler.
63.2 Example
The next example will use the Type Hints library
load "typehints.ring"
see sum(3,4) + nl ;
see sayHello("Mahmoud");
int func sum(int x,int y) {
return x+y ;
}
string func sayHello(string name) {
return "Hello " + name ;
}
63.3 User Types
The Type Hints library is very powerful and will support user types (Classes) automatically
Example:
load "typehints.ring"
import mypackage
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7. Ring Documentation, Release 1.5.4
test() { main([:one,:two,:three]) }
myclass func test() {
see "Testing User Types!" + nl
return new myclass
}
package mypackage {
public class myclass {
public static void func main(list args) {
see "welcome" + nl
see args
}
}
}
63.4 Using Types inside Code
Also you can use the types inside the code (not only the function prototype)
Example:
load "typehints.ring"
int sum = sum(3,4)
string msg = sayHello("Mahmoud")
see "Sum = " + sum + nl + msg + nl
int func sum(int x,int y) {
return x+y ;
}
string func sayHello(string name) {
return "Hello " + name ;
}
63.5 Rules
• To use the types in the function prototype you must use ‘(‘ and ‘)’ around parameters
• To use the types in the function code, You must set the variable value (Assignment).
The next types are defined by the library
# Low Level Types
char
unsigned
signed
int
short
long
float
63.4. Using Types inside Code 721

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double
void
# High Level Types
string
list
number
object
# Other
public
static
abstract
protected
override
63.5. Rules 722

9. CHAPTER
SIXTYFOUR
DISTRIBUTING RING APPLICATIONS
In this chapter we will learn about distributing Ring applications.
64.1 Distributing Applications for Microsoft Windows
Step 1:
Copy c:ringbin folder to be for example c:myapp
Step 2:
Rename c:myappring.exe to c:myappmyapp.exe
Step 3:
Create a file c:myappring.ring
And write
Load "myapp.ring"
When you run myapp.exe the file ring.ring will be executed automatically
So your file myapp.ring will be called and executed
Or just rename myapp.ring to ring.ring
It’s a fast way to distribute applications.
64.2 Protecting the Source Code
Step 1:
Execute the next command
ring myapp.ring -go
This will generate one object file (myapp.ringo) from the project files (*.ring)
Step 2:
Rename myapp.ringo to ring.ringo
When you run the executable file (ring.exe) or (myapp.exe) the file ring.ringo will be executed.
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64.3 Creating Windows Installer
There are many tools that you can use to distribute your application.
Check : nullsoft scriptable install system
URL : http://nsis.sourceforge.net/Main_Page
64.4 Using C/C++ Compiler and Linker
Another method to distribute applications is to use a C/C++ compiler.
Ring can be embedded in C/C++ projects, We can create executable files using a C/C++ compiler by embedding the
Ring language in our project.
Check the “Embedding Ring Language in C/C++ Programs” chapter.
Using this way we will avoid using ring.ring or ring.ringo files.
64.5 Distributing Applications and Games for Mobile
Ring can be embedded in a Qt projects or LibSDL projects to build Mobile applications and Games.
You can build the Qt project or the LibSDL project and get the Android package directly (*.apk)
Check Ring distributions for Mobile development using Qt or LibSDL.
64.3. Creating Windows Installer 724