[Python-ideas] No implicit variable declarations

[James Nelson]

Markus Unterwaditzer <markus at ...> writes:
> 
> Hello James,
> 
> I see how this would help with avoiding a whole class of errors, but then 
i
> also think your two suggestions -- the var and implicit keywords -- would 
take
> a great deal of flexibility and expressiveness from the language. Also, 
Python
> was never meant to be statically typed, so suggesting static typing so 
many
> years after its creation is IMO pointless, even though you're suggesting 
it to
> be optional. OTOH I like your idea of suggesting variable names when 
NameError
> is raised, but i don't know how easy this is to implement in CPython.
> 
> I also want to say that the kind of error you're describing never occured 
to me
> in practice. The mistake of assigning to the wrong variable name (and not
> noticing it immediately through an exception) seems to me like something 
that
> only occurs when deliberately writing huge cludges of spaghetti-code, or 
when
> you're simply not using enough namespaces.
> 

I don't believe that having var and implicit keywords would make the 
language less flexible -- they are completely optional, remember. If you 
omit "implicit none" from the beginning of your program you can write your 
program like you do now, implicit variable declarations and all.

In retrospect, statically typed variables does contradict Python's duck 
typing: it shouldn't matter if it's a float or an integer, as long as you 
multiply or divide, you're fine, and if you need a specific type, you just 
check with type().

 - JN