Coding style

[oxygen]

You are a book author, yet your coding style is lacking at least about new lines after each and every one line if.

For example:
if (argc == 1) return runRepl(vm);

It looks as if you trying to save lines of code.
No offence, this is a bad habbit which produces nothing. Not even readability, on the contrary.

:)

[kmarekspartz]

There is a consistent style for that. If there is no else clause and the consequent is a single line, use no newline. I find this more readable than the return runRelpl(vm) if (argc == 1) style Ruby has.

Please avoid ad hominem attacks.

See: #96 (comment)

[munificent]

Yes, like @zeckalpha said, one-line if statements are OK.