what do these mean

[Chris Angelico]

On Mon, May 21, 2012 at 2:52 AM, e-mail mgbg25171
<mgbg25171 at blueyonder.co.uk> wrote:
> def rJnz (cod,p) : return (cod[p],p+1)[ds.pop()]
> def rJz  (cod,p) : return (p+1,cod[p])[ds.pop()==0]
>
> Specifically I'm stuck on what (code[p], followed by p+1 does inside the
> brackets

(cod[p],p+1) is a two-item tuple with [0] equal to cod[p] and [1]
equal to p+1. It takes the next element off the list ds and indexes
that little tuple with it. It's like this:

def rJnz (cod,p):
    if ds.pop()==1: return p+1
    return cod[p]

def rJz  (cod,p):
    if ds.pop()==0: return cod[p]
    return p+1

> ds.pop() == 0 either means that the result popped is 0 or that there are no
> items left in list ds[]

If there are no items left. pop() will raise an exception.

ChrisA