Prism Metaprogramming Tool released
24 Oct 1999 05:55:04 +0200
>>>>> "Jim" == James Little <email@example.com> writes:
>> >>>>> "Jim" == Jim Little <firstname.lastname@example.org> writes:
Jim> Prism development will proceed in four phases: * The
>> "assembly Jim> language" phase. * The "modern language" phase.
>> * The Jim> "domain-specific language" phase. * The "TUNES"
>> Is it real necessary to have these 4 phases ? Why should we
>> define integer arithmetics before object orientation ?
Jim> Hmm, good question. The short answer is that new Prism
Jim> languages are written with existing Prism languages. It's
Jim> easier to start by creating small building blocks, then using
Jim> those to create larger structures.
Yes, of course. But I'm not sure that integers are required to do
interesting things, other than arithmetics. I think that sets and
operations on them are more powerful and more needed. But it's a
matter of what you want to do.
Jim> Here's the detailed plan for the first phase and the
>> beginning Jim> of the second: * Create a parser for integers *
>> Create programs Jim> to do integer arithmetic
>> To be honest, integer arithmetic is alsmost the first thing I've
>> done with OIL :-). But I didn't have to create a parser. I'll
>> probably do one in the future, but it is not required.
Jim> Integer arithmetic is the first thing we'll do with Prism, too.
Jim> :) Once we have integer arithmetic, we can write meaningful
Jim> program. Our first meaningful program will be an assembler
Jim> metaprogram for the Prism virtual machine. To create the
Jim> assembler, we need the ability to parse integers.
Jim> (Right now, there's an assembler, but it's written in Perl. We
Jim> need to bootstrap Prism by porting the assembler to the Prism
Jim> Control metamodel. Prism Control is the Prism VM's "machine
>> To avoid the parser, I just defined two functions bin2int and
>> int2bin, to convert from list of `0' and `1' to integers, and
>> vice-versa. Therefore, the user can type :
>> add [bin2int (1 1)] [bin2int (1 0 1)] => 10094 bin2int 10094 =>
>> 10096 = (1 0 0 0)
>> (Yes I kow, the syntax is very unsual).
Jim> It would be possible to do something similar in Prism -- you
Jim> could specify the integer models directly -- but that gets
Jim> pretty tedious after a while. :)
>> So we can do an addition without having to parse integers.
Jim> Definitely true. I didn't mean to imply that we had to write
Jim> the integer parser before we could implement integer
Jim> arithmetic. Rather, both are necessary before we can create
Jim> the Prism/Control assembler.
Sure. I'm just trying to really separate UI from semantics so that in
the end, semantics do not depend on UI and UI can be changed easily.
Jim> By the way, where can I learn more about OIL?