[plt-scheme] Why do folks implement *dynamically* typed languages?

On Jun 2, 2007, at 7:43 AM, Anton van Straaten wrote:

> Richard Cobbe wrote:
>> On Fri, Jun 01, 2007 at 09:27:54AM -0400, hendrik at topoi.pooq.com  
>> wrote:
>>> On Wed, May 30, 2007 at 09:06:53PM -0400, Anton van Straaten wrote:
>>>
>>>> That issue alone can make the argument for a language like Ruby, or
>>>> Scheme, in many cases.  Languages that put you in control in the  
>>>> way
>>>> that DLs do have been called "freedom languages":
>>>>
>>>>  http://codecraft.info/index.php/archives/20/
>>>
>>> I've heard languages tha put you in control that SLs do called
>>> "police-state languages".
>> Ah, nothing brings reason to a discussionlike an emotionally and
>> politically loaded analogy.
>> (To be clear: "freedom" is just as loaded as "police-state.")
>
> All true, but in the context of the original question, there's a  
> reason for invoking emotions.  There's no purely objective basis  
> for picking one of these languages over another, and the subjective  
> reasons to do so are at least partly emotional: how programming in  
> a language "feels" to the programmer.
>
> The emotional descriptions are supposed to communicate those  
> feelings, to help explain why some people might choose one language  
> over another.  These descriptions shouldn't be offered or  
> understood as absolute or objective assessments, but of course they  
> often are -- after all, flamewars need fuel!
>
> Strangely, the above hints at one of the motivations for formal  
> type systems: by restricting oneself to reasoning within such a  
> system, one can conveniently dismiss as meaningless all the fuzzy  
> liberal arts considerations that arise outside of the formal  
> system.  That's a rather fascist position, though.  ;)
>
> Anton

In 1957, during a scene in Bridge on the River Kwai, the commander of  
the prisoners is explaining that it would be illegal for them to  
attempt to escape from the prisoner of war camp (because they were  
ordered to surrender) :

...
Shears: I'm sorry sir. I didn't quite follow you. You mean you intend  
to uphold the letter of the law, no matter what it costs.

Nicholson: Without law, Commander, there is no civilization.

Shears: You just took my point. Here, there is no civilization.

Nicholson: Then, we have the opportunity to introduce it. I suggest  
that we drop the subject of escape.
...

Are we 'ordered' into software prisons that have too much freedom?   
Do we choose type systems to introduce a higher level of  
civilization?  Are we trying to escape to other programming paradigms?

rac





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