Re: My thoughts on C# and gaming.

On Wed, Jan 27, 2010 at 7:45 PM, Bill Kelly <[email protected]> wrote:
> Emil Dotchevski wrote:
>> On Wed, Jan 27, 2010 at 2:00 PM, Bill Kelly <[email protected]> wrote:
>>> Emil Dotchevski wrote:
>>>> On Wed, Jan 27, 2010 at 2:26 AM, Bill Kelly <[email protected]> wrote:
>>>>>> Being able to do things like this is not what makes a language great.
>>>>>> In fact I am not sure what makes most languages great. It seems to me
>>>>>> that most languages should have been a C++ library or a LISP library
>>>>>> instead -- all other differences are primarily syntactical in nature
>>>>>> and thus not very interesting as far as I am concerned.
>>> An example of a Ruby DSL, in this case an assembler for Common
>>> Intermediate Language bytecode:
>>>
>>>  http://www.iunknown.com/2005/12/refining-the-ru.html
>>>
>>>   require 'RbDynamicMethod'
>>>
>>>   RbDynamicMethod::create_ruby_method('say_hello') do
>>>     include  'System, System.Collections'
>>>     ldstr    'Hello, World, int = {0}, double = {1}'
>>>     ldc_i4   42
>>>     box      'Int32'
>>>     ldc_r8   3.141592654
>>>     box      'Double'
>>>     call     'static Console.WriteLine(String,Object,Object)'
>>>     br_s     'end_of_method'
>>>     ldstr    'Goodbye, World'
>>>     call     'static Console.WriteLine(String)'
>>>     label    'end_of_method'
>>>     ldc_i4_4
>>>     ret
>>>   end
>>
>> Compare such VM design to the simplicity of a LISP interpreter. LISP
>> is not just the grandfather of all dynamic languages, it is the most
>> basic and most powerful of the bunch.
>>
>> C++ is similarly basic and powerful in the "static type checking"
>> domain. In fact it is C++ that introduced the concept to begin with,
>> only later it was adopted by C.
>
> I apologize if we are talking at cross-purposes or if I have been
> unclear in conveying my point.
>
> In posting the above Ruby DSL, I was attempting to respond to
> your statement, "all other differences are primarily syntactical
> in nature and thus not very interesting as far as I am concerned."
>
> As cool as Lisp is--which I have gleaned more from reading about
> its design than from my meager experience with the language so far--
> my understanding is that Lisp syntax won't allow an uncluttered
> DSL like the above to be parsed *as Lisp*.
>
> Ruby syntax, on the other hand, is flexible enough to parse the
> above *as Ruby*.
>
> As such, it is relatively common for Ruby programmers to create
> so-called internal DSLs rather than external DSLs, when the intent
> is simply to bring the programming language itself closer to the
> problem domain.  (Obviously if the DSL is intended to be edited by
> an untrusted user, than an internal DSL would be a poor choice.)
>
> At the risk of belaboring the point, my argument is that Ruby's
> syntactical flexibility is useful, and as far as I know, can't
> readily be mimicked by the other languages we've been discussing.

Actually, with read-macros in LISP, you can make LISP look like
anything, so you could probably change:
  p ARGF.read.scan(/\d{1,3}(\.\d{1,3}){3}/).uniq.size
Into a Lisp version of something like:
 #Ruby p ARGF.read.scan(/\d{1,3}(\.\d{1,3}){3}/).uniq.size

Lisp can literally become anything.  The combination of macros and
read-macros are insanely powerful.  The D language comes pretty close
to that power (although not completely) with its string templates and
mixin support.  You can quite *literally* make a Ruby parser embedded
in Lisp in such a way that you can freely mix both.
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