syntax difference

[Bart]

On 18/06/2018 01:10, Chris Angelico wrote:
> On Mon, Jun 18, 2018 at 9:30 AM, Rick Johnson
> <rantingrickjohnson at gmail.com> wrote:
>> On Sunday, June 17, 2018 at 2:07:40 PM UTC-5, Jim Lee wrote:
>>
>>> IMHO, trying to shoehorn static type checking on top of a dynamically
>>> typed language shows that the wrong language was chosen for the job.
>>
>> Exactly.
>>
>> I'm not against the idea of Python growing a new feature.
>> Features are great. My objection is concerned merely with
>> the "how" it is implemented, not the "why" it was
>> implemented.
>>
>> "Type-hint comments" would allow:
>>
>>   (1) those who need them, to use them.
>>
>>   (2) those who don't care about them, to totally ignore
>>       them.
>>
>>   (3) and those who utterly *HATE* them, to write a simply
>>       little function which will strip them from any and all
>>       source code they might be forced to maintain.
> 
> Awwww. Isn't it cute, how he thinks that comments are easier to remove
> than other elements equally well defined in the grammar?

You're right in that neither task is that trivial.

I can remove comments by writing a tokeniser which scans Python source 
and re-outputs tokens one at a time. Such a tokeniser normally ignores 
comments.

But to remove type hints, a deeper understanding of the input is needed. 
I would need a parser rather than a tokeniser. So it is harder.

Both methods would fail with source code that exists as a string 
constant (for exec() for example), or source code that is synthesised at 
runtime.

-- 
bart