While loops 

While loops are written using WHILE(...) DO BLOCK(...):

WHILE(TRUE) DO BLOCK(
  Predef_println APPLY LIT("Hello")
)

This prints as:

```scala while (true) { println(“Hello”) }

Do loops 

Do loops are written by calling DO_WHILE(...) on a block:

BLOCK(
  Predef_println APPLY LIT("Hello")
) DO_WHILE(TRUE)

This prints as:

do {
  println("Hello")
} while (true)