| Each Mason component is compiled as necessary into a Perl subroutine, which is then compiled into Perl opcodes. |
| That means, the call to a subroutine must be on its program line rather than somewhere in an expression. |
| The interesting thing is to watch them write a subroutine that counts all the bits in a byte, then ask them to make it much, much faster. |
| A unit test would directly call the subroutine I want to test, and it would rely as little as possible on other subroutines in the program. |
| The first, unit testing, tests a very small subroutine to see that it does what it should. |
| Every time the subroutine calls itself, a few bytes are pushed on to the stack to store the return address. |
