Crazy Code using Ring - Part (8) - Mixing nested anonymous functions, Eval() & BraceEnd()

[Mahmoud Fayed]

Hello

Check the next sample, it contains multiple lessons/ideas

It's written in this way to introduce & mix these ideas together in one sample

i.e. it's not a guide to mix these features together (just learn about them and use what you need)

Features:

* Nested anonymous functions

* Calling anonymous function as a method

* Using Eval()

* Using BraceEnd() & avoiding the infinite BraceEnd() trap

$Server = new Server { host = "http://0.0.0.0" port = 3000 }

// We don't need to use new to create the object because it's already created

$Server {

    // We access host and port attributes from our anonymous function

    @get( "/", func {

        ? "Server running on " + host + ":" + port

    })

} // This will call braceEnd() method

class Server

    host port

   

    myfunc       = NULL

    lRunBraceEnd = True

 

    func @get cURL,fFunc

        // myfunc will be another anonymous function that call our anonymous function as method

        // Since myfunc is a string (contains the function name)

        // It's easy to pass it to C functions and call it from C libraries

        // I.e. we created a wrapper so our original anonymous function act as a $Server method

        // This avoid passing the object to the function or using $server.host to access the host attribute

        myfunc = Eval(`return func {

            vFunc = "`+fFunc+`"

            $Server { call { vFunc() } }

            }

        `)

    func braceEnd

        // braceEnd could be a trap if we are not careful

        // because we call myfunc() which access $Server using braces which call braceEnd() again

        // To avoid the infinite loop we use the lRunBraceEnd attribute

        if myfunc

            if lRunBraceEnd = True

                lRunBraceEnd = False

                call myfunc()

                lRunBraceEnd = True

            ok

        ok

Greetings,

Mahmoud