callme

callme-1.js

call.exec = true;
call.toc = true;



call(callme, 1);

function callme(i) {
    if (i < 0) return i;
    console.log(i);
    return call(callme, i + 1);
}


// function call(fn, ...args) {
//     let callable = {fn, args};
//     callable.__proto__ = call.prototype;
//     return callable;
// }
// 
// function TCO(result) {
//     while(result instanceof call){
//         let {fn, args} = result;
//         result = fn(...args);
//     }
//     return result;
// }
//
// TCO(callme(1))

function call(fn, ...args) {
    if(call.exec){
        if(call.toc) call.exec = false;
        let result = fn(...args);
        while(result instanceof call){
            let {fn, args} = result;
            result = fn(...args);
        }
        console.log(call.exec, call.toc);
        call.exec = true;
        return result;
    } else {
        let callable = {fn, args};
        callable.__proto__ = call.prototype;
        return callable;
    }
}

callme-2.js

function callme(i) {
    if (i < 0) return i;
    console.log(i);
    return call(callme, i + 1);
}


function call(fn, ...args) {
    let callable = {fn, args};
    callable.__proto__ = call.prototype;
    return callable;
}

function TCO(result) {
    while(result instanceof call){
        let {fn, args} = result;
        result = fn(...args);
    }
    return result;
}
TCO(callme(1))

callme.py

class Callable:
    def __init__(self, fn, *args, **kargs):
        self.fn = fn
        self.args = args
        self.kargs = kargs
    def __call__(self):
        return self.fn(*self.args, **self.kargs)

class Context:
    def __init__(self):
        self.exec = True
    def tco(self, fn):
        def _fn(*args, **kargs):
            if self.exec:
                self.exec = False
                result = fn(*args, **kargs)
                while type(result) == Callable:
                    result = result()
                self.exec = True
                return result
            else:
                return Callable(fn,*args,**kargs)
        return _fn

ctx = Context()

@ctx.tco
def callme(i):
    if i < 0: return i
    print(i)
    return callme(i-1)

callme(5)
callme(5)

callme.rb

def callme(i)
  return i if i < 0
  puts i
  return callme i+1
end

main.rb

# main.rb
RubyVM::InstructionSequence.compile_option = {
  tailcall_optimization: true,
  trace_instruction: false
}

require './callme.rb'

(callme 1)