The document discusses embedding Ring programs within other Ring programs using the ringvm library. It describes functions for running Ring code in isolated states to prevent conflicts, executing programs serially, passing variables between states, and running Ring programs from other programs while controlling memory management. The goal is to provide safe integration of Ring programs and applications.

1. Ring Documentation, Release 1.7
y: 20.000000
z: 30.000000
70.27 ringvm_give() function
Using the ringvm_give() function we can redefine the behavior of the Give command
Example:
see "Name: " give name
see "Hello " + name
func ringvm_give
see "Mahmoud" + nl
return "Mahmoud"
Output:
Name: Mahmoud
Hello Mahmoud
70.27. ringvm_give() function 812

2. CHAPTER
SEVENTYONE
THE TRACE LIBRARY AND THE INTERACTIVE DEBUGGER
In this chapter we will learn about the Trace Library and the Interactive Debugger
71.1 Loading the Trace library
To start using the Trace library, We must load it first!
load "tracelib.ring"
71.2 Trace All Events
The next example demonstrates the Trace library usage to trace all events.
# Trace All Events
trace(:AllEvents)
see "Hello, world!" + nl
see "Welcome" + nl
see "How are you?" +nl
mytest()
new myclass { mymethod() }
func mytest
see "Message from mytest" + nl
class myclass
func mymethod
see "Message from mymethod" + nl
71.3 Trace control flow between functions
The next example demonstrates the Trace library usage to trace the control flow between functions.
Trace(:Functions)
test1()
813

3. Ring Documentation, Release 1.7
func test1
see :test1 + nl
test2()
func test2
see :test2 + nl
see test3() + nl
func test3
see :test3 + nl
return "test 3 output"
71.4 Pass Error
The next example demonstrates the Trace library usage to pass an error!
Trace(:PassError)
test1()
func test1
x = 10
see :test1 + nl
test2() # Runtime Error!
see "We can continue!"
71.5 Interactive Debugger
The next example demonstrates the Trace library usage to use the Interactive Debugger
Trace(:Debugger)
test1()
see "good bye!" + nl
func test1
x = 10
see :test1 + nl
t = 12
test2() # Runtime Error!
see "After Error!" +nl
see "t = " see t see nl
see "x = " see x see nl
71.6 Execute Program Line by Line
The next example demonstrates the Trace library usage to execute the program line by line!
Trace(:LineByLine)
test1()
71.4. Pass Error 814

4. Ring Documentation, Release 1.7
func test1
x = 10
see :test1 + nl
t = 12
test2()
see "After Error!" +nl
see "t = " + t + nl
71.7 BreakPoint
The next example demonstrates the Trace library usage to stop at a breakpoint!
test1()
func test1
x = 10
see :test1 + nl
t = 12
BreakPoint()
see "After breakpoint!" +nl
see "t = " + t + nl
see "End of program!" + nl
71.8 Disable BreakPoints
The next example demonstrates the Trace library usage and how to disable the Breakpoints!
NoBreakPoints()
test1()
func test1
x = 10
see :test1 + nl
t = 12
BreakPoint()
see "After breakpoint!" +nl
see "t = " + t + nl
see "End of program!" + nl
71.9 Using the Interactive Debugger
The next example uses a Breakpoint to open the Interactive Debugger!
load "tracelib.ring"
test1()
func test1
x = 10
see :test1 + nl
t = 12
71.7. BreakPoint 815

5. Ring Documentation, Release 1.7
BreakPoint()
see "After breakpoint!" +nl
see "t = " + t + nl
see "End of program!" + nl
Screen Shots:
We have the Interactive Debugger at the Breakpoint!
We can print the variables values
We can change the variables values then continue execution
71.9. Using the Interactive Debugger 816

6. Ring Documentation, Release 1.7
We can run the Interactive Debugger in the Output Window
71.9. Using the Interactive Debugger 817

7. CHAPTER
SEVENTYTWO
EMBEDDING RING IN RING
In this chapter we will learn about embedding Ring in Ring programs and applications.
72.1 Embedding Ring in Ring without sharing the State
From Ring 1.0 we already have functions for embedding Ring in the C language. Also we can execute Ring code
inside Ring programs using the eval() function. In this release we provide functions for embedding Ring in Ring
programs without sharing the state.
Advantages:
1. Quick integration for Ring programs and applications together without conflicts.
2. Execute and run Ring code in safe environments that we can trace.
Example:
pState = ring_state_init()
ring_state_runcode(pState,"See 'Hello, World!'+nl")
ring_state_runcode(pState,"x = 10")
pState2 = ring_state_init()
ring_state_runcode(pState2,"See 'Hello, World!'+nl")
ring_state_runcode(pState2,"x = 20")
ring_state_runcode(pState,"see x +nl")
ring_state_runcode(pState2,"see x +nl")
v1 = ring_state_findvar(pState,"x")
v2 = ring_state_findvar(pState2,"x")
see v1[3] + nl
see V2[3] + nl
ring_state_delete(pState)
ring_state_delete(pState2)
Output:
Hello, World!
Hello, World!
10
20
10
20
818

8. Ring Documentation, Release 1.7
72.2 Serial Execution of Programs
We can execute application after another application using ring_state_main()
Example:
chdir(exefolder()+"/../applications/formdesigner")
ring_state_main('formdesigner.ring')
chdir(exefolder()+"/../applications/cards")
ring_state_main('cards.ring')
72.3 ring_state_setvar()
Using ring_state_setvar() we can set variables value
The value could be (String, Number, List or C Pointer)
We need this function to quickly pass lists and C pointers to the Sub Ring Environment
Syntax:
ring_state_setvar(oState,cVariableName,Value)
Example:
load "guilib.ring"
myapp = null
win = null
func main
myapp = new qApp {
win = new qWidget() {
setWindowTitle("Advanced Example on using ring_state_setvar()")
move(100,100)
resize(600,400)
new qPushButton(win) {
setText("Test")
setClickEvent("Test()")
}
# We need this because using load 'guilib.ring' in the sub environment
# Will create timers by Qt and closing the window will not be enough
# To close the application
oFilter = new qAllEvents(win)
oFilter.setCloseEvent("myapp.quit()")
win.installeventfilter(oFilter)
show()
}
exec()
}
func test
pState = ring_state_init()
ring_state_runcode(pstate,"load 'guilib.ring'")
ring_state_runcode(pState,"x = NULL")
# Pass String
ring_state_setvar(pState,"x","hello")
72.2. Serial Execution of Programs 819

9. Ring Documentation, Release 1.7
ring_state_runcode(pState,"? x")
# Pass Number
ring_state_setvar(pState,"x",100)
ring_state_runcode(pState,"? x")
# Pass List
ring_state_setvar(pState,"x",["one","two","three"])
ring_state_runcode(pState,"? x")
# Pass Object
# We can't pass the Ring Object (win)
# Because Objects store pointers to the Class Information
# And the class is related to the Parent Ring Environment
# And the sub Ring environment can't access it
# But we can pass C pointers like win.pObject
ring_state_setvar(pState,"x",win.pObject)
# Now we create the object again but using the same C pointer
# So we have access to the Same window in the parent Ring enviroment
ring_state_runcode(pState,"
new qWidget {
pObject = x
setwindowtitle('Message from the Sub Ring Environment')
}
")
ring_state_delete(pState)
72.4 ring_state_new() and ring_state_mainfile()
Using ring_state_new() and ring_state_mainfile() we can run Ring programs from Ring programs
But unlike ring_state_main(), Here we can control when to delete the Ring state!
This is important when we run GUI programs from GUI programs
Because they will share the GUI Library (RingQt), And In this case the caller will call
qApp.Exec()
So the sub program, will not stop and will return to the Main program
Here deleting the State of the sub programs will lead to a problem when we run the sub program events
So keeping the state is important for sub GUI programs hosted in GUI programs.
Example:
load "guilib.ring"
func main
new qApp {
win = new qWidget() {
setWindowTitle("Test ring_state_mainfile()")
resize(400,400) move(100,100)
btn = new qPushButton(Win) {
settext("test")
setclickevent("mytest()")
}
show()
}
exec()
}
72.4. ring_state_new() and ring_state_mainfile() 820

10. Ring Documentation, Release 1.7
func mytest
pState = ring_state_new()
ring_state_mainfile(pState,"runprogram.ring")
# Here we don't delete the state if we will run GUI application
# So we can run the GUI application events
// ring_state_delete(pState)
If you will use this feature, remember to update the previous example based on your application needs
So you can call ring_state_delete() at some point to avoid the memory leak!
72.4. ring_state_new() and ring_state_mainfile() 821