Help improve program for parsing simple rules

[Aaron Brady]

On Apr 17, 12:15 pm, Paul McGuire <pt... at austin.rr.com> wrote:
> On Apr 17, 10:43 am, John Machin <sjmac... at lexicon.net> wrote:
snip
> not only does this handle
> "0.00 LE A LE 4.00", but it could also evaluate "0.00 LE A LE 4.00 LE
> E > D".  (I see that I should actually do some short-circuiting here -
> if ret is false after calling fn(val1,val2), I should just break out
> at that point.  I'll have that fixed in the online version shortly.)

Hi, not to offend; I don't know your background.  One thing I like
about Python is it and the docs are careful about short-circuiting
conditions.  ISTR that C left some of those details up to the compiler
at one point.

>>> def f():
...     print( 'in f' )
...     return 10
...
>>> 0<f()<20
in f
True
>>> 0<f() and f()<20
in f
in f
True

Therefore, if op{n} has side effects, 'op1 operator1 op2 AND op2
operator2 op3' is not equivalent to 'op1 optor1 op2 optor2 op3'.