Nick Craig-Wood <[EMAIL PROTECTED]> wrote:
> Here is a different solution...
>
> class Result:
> def set(self, value):
> self.value = value
> return value
>
> m = Result()
>
> if m.set(re.search(r'add (\d+) (\d+)', line)):
> do_add(m.value.group(1), m.value.group(2))
> elif m.set(re.search(r'mult (\d+) (\d+)', line)):
> do_mult(m.value.group(1), m.value.group(2))
> elif m.set(re.search(r'help (\w+)', line)):
> show_help(m.value.group(1))
This is roughly the same as my Cookbook recipe for test-and-set, but if
all you're using it for is RE search and MO access you might be better
off giving more responsibilities to your auxiliary class, such as:
class ReWithMemory(object):
def search(self, are, aline):
self.mo = re.search(are, aline)
return self.mo
def group(self, n):
return self.mo.group(n)
m = ReWithMemory()
if m.search(r'add (\d+) (\d+)', line):
do_add(m.group(1), m.group(2))
elif m.search(r'mult (\d+) (\d+)', line):
do_mult(m.group(1), m.group(2))
elif m.search(r'help (\w+)', line):
show_help(m.group(1))
Demeter's Law suggests that the 'm.value.group' accesses in your
approach are better handled by having m delegate to its `value'; and the
repeated m.set(re.search( ... seem to be a slight code smell, violating
"once and only once", which suggests merging into a single `set' method.
Your approach is more general, of course.
Alex
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