[Compiler-sig] Type checking
John Max Skaller
skaller@maxtal.com.au
Tue, 09 May 2000 15:37:11 +1000
Charles E Jenkins wrote:
>
> Hello to all. I hope this is the correct forum for asking about the whys and
> wherefores of Python compilation.
>
> I, too, am interested in seeing strong type-checking added to the language. I
> wonder what technical reasons prevent strong runtime type-checking from being
> added.
>
> Here's how naive I am. I would think it would be as easy as
>
> def myFunc1( num is IntType )
> def myFunc2( any_list is ListType )
> def myFunc3( string_list is ListType of StringType )
>
Vyper implements this right now.
The syntax is to use operator ! rather than 'is':
def myFunc1 ( num ! IntType): ...
You can also check expressions:
x = value ! IntType # raises TypeError if value isn't an int
> I call myself naive because this is so easy that there must be a very good
> reason why Python doesn't have these facilities!
Politics. I implemented the above operator, whose design
is attributed to Greg Stein in a couple of days.
--
John (Max) Skaller, mailto:skaller@maxtal.com.au
10/1 Toxteth Rd Glebe NSW 2037 Australia voice: 61-2-9660-0850
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