[EMAIL PROTECTED] wrote:
> Hi,
>
> I'm writing a hand-written recursive decent parser for SPICE syntax
> parsing. In one case I have one function that handles a bunch of
> similar cases (you pass the name and the number of tokens you're
> looking for). In another case I have a function that handles a
> different set of tokens and so it can't use the same arguments as the
> first one, and in fact takes no arguments. However, these functions
> are semantically similar and are called from the same place one right
> after the other.
>
> I'd like to have a dictionary (actually a nested dictionary) to call
> these functions so I can avoid if-then-elsing everything. Eath
> dictionary item has three things in it: the function to be called, a
> string to pass to the function (which is also the key to the dict), and
> a tuple to pass to the function. In the case of the function with no
> arguments, obviously I'd like not to pass anything.
>
> I'm trying to do this 'functionally' (i guess), by avoiding
> if-then-elses and just calling out the functions by accessing them and
> their arguments from the dictionary.
>
> something like this:
> alldict = \
> {'pulse': {'func': self.arbtrandef, 'args':(2,5)},\
> 'sin' : {'func': self.arbtrandef, 'args':(2,3)},\
> 'exp' : {'func': self.arbtrandef, 'args':(2,4)},\
> 'pwl' : {'func': self.pwldef , 'args': (None,)},\
> <------- how
> do I store "no" arguments?
> 'sffm' : {'func': self.arbtrandef, 'args':(5,0)}}
>
> for it in alldict.items():
> name = it[0]
> args = (name,) + it[1]['args']
> it[1]['func'](*args)
>
> So basically this doesn't work.
>
> Any thoughts?
You could omit the 'args' entry completely and test for this in the
dispatch:
'pwl' : {'func': self.pwldef},\
for name, params in alldict.items():
try
args = (name,) + params['args']
except KeyError:
args = ()
params['func'](*args)
Or include the 'name' parameter in the arg list and use an empty tuple
for the arg to pwldef:
'exp' : {'func': self.arbtrandef, 'args':('exp', 2,4)},\
'pwl' : {'func': self.pwldef , 'args': ()},\
for name, params in alldict.items():
params['func'](*args)
Kent
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