Re: Small time coding [Was: Re: About Visual Basic [Was: Industry versus academia]]

[Scott McKay <address@hidden>]

At 4:04 PM -0500 3/12/03, Bob Cassels wrote:
>anton@appsolutions.com wrote:
>
>>Christopher Barber wrote:
>>
>>>The Curl language has optional type annotations.  Variables with
>>>undeclared types are given the compile-time type of 'any', which
>>>is the supertype of all other types.  Type checking involving anys
>>>is deferred until runtime while that with other types is done at
>>>compile time.
>>>   
>>>
>>
>>That's excellent.  It's interesting how few languages do this.
>>
>
>Dylan did it... Also compile-time method dispatch where possible. 
>This required that relevant functions and/or classes be "sealed", 
>stating that relevant methods could not be added dynamically after 
>compilation.

More precisely, Dylan allowed the programmer to make the trade-off:
  - If you want to generate better code (e.g., compiler does method
    dispatch at compile-time), you could "seal" classes or functions.
  - If you want easier development or more extensible libraries, you
    don't bother sealing.
Knowing exactly when to seal requires practice...