refactor: change sample structure

sample/check_prime_number.nk

@@ -1,12 +1,13 @@
-fn main() -> void 
+fn main() -> i64
 {
-    let:i32 n = 10;
-    let:i32 i = 2;
-    let:i32 count = 0;
+    let:i64 n = 10;
+    let:i64 i = 2;
+    let:i64 count = 0;
+    let:i64 j = 0;
 
     for ( i -> n :: 1 ) 
     {
-        let:i32 j = n;
+        j=n;
         j %= i;
 
         if ( j == 0 ) 
@@ -16,11 +17,11 @@ fn main() -> void
     }
 
     if (count == 0) {
-        println("this is prime number!");
+        println(1);
     }
     if (count != 0) {
-        println("this is not prime number!");
+        println(0);
     }
 
-    return;
+    return 0;
 }

sample/fibonacci.nk

@@ -7,15 +7,15 @@ fn fibonacci(i64:n) -> i64
 	}
 	else {
 		return_val = fibonacci( n-1 ) + fibonacci( n-2 );
-
 	}
 	return  return_val;
 }
 
 fn main() -> i64
 {
-	let:i64 x = 47;
-	return fibonacci(x);
+	let:i64 x = 35;
+	println(fibonacci(x));
+	return 0;
 }
 
 

sample/hello_world.nk

@@ -1,5 +1,8 @@
-fn main() -> void
+fn main() -> i64
 {
-	println("Hello World!");
-	return;	
+	let:i64 a = 2345;
+	let:i64 ab = 125;
+	let:String b = "hi";
+	println("hellooo hi {}", b);
+	return 0;	
 }

sample/import_statement/fibonacci.nk

@@ -3,6 +3,20 @@ fn adder(i64:a, i64:b) -> i64
 	return a + b;
 }
 
+fn adder_fibonacci(i64:n) -> i64
+{
+	let:i64 return_val = 0;
+	if(n < 2)
+	{
+		return_val = n;
+	}
+	else {
+		return_val = adder(adder_fibonacci( n-1 ), adder_fibonacci( n-2 ));
+
+	}
+	return  return_val;
+}
+
 fn fibonacci(i64:n) -> i64
 {
 	let:i64 return_val = 0;
@@ -11,7 +25,7 @@ fn fibonacci(i64:n) -> i64
 		return_val = n;
 	}
 	else {
-		return_val = adder(fibonacci( n-1 ), fibonacci( n-2 ));
+		return_val = fibonacci( n-1 ) + fibonacci( n-2 );
 
 	}
 	return  return_val;

sample/triangle.nk

@@ -1,14 +1,15 @@
-fn main() -> void
+fn main() -> i64
 {
-	let:i32 i = 0;
+	let:i64 i = 0;
+	let:i64 j = 0;
 	for(i -> 10 :: 1)
 	{
-		let:i32 j = 0;
+		j = 0;
 		for(j -> i :: 1)
 		{
 			print("*");
 		}
-		println(" ");
+		println("");
 	}
-	return ;
+	return 0;
 }