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Re: colon colon

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Rod Pemberton wrote:
> "Fanzo" <cristianof6@gmail.com> wrote in message
> news:4ffc6c61$0$1375$4fafbaef@reader2.news.tin.it...
>> Developing my own forth, im tring to make all definitions as possible
>> from inside the minimal interpreter.
>>
>> So the result is "write only language"
>>
>> I had difficulties to understand what i did one month ago
>> to define "colon"
>>
>>
>> createheader :
>>    1301 ,
>> 32 word createheader find
>> now 501 ,n 801 ,n execute ,     | compile DROP on the fly
>>    1301 ,
>> 32 word smudge find
>> now execute ,
>>    1301 ,
>> 32 word ] find
>> now execute ,
>>    801 ,
>>
>>                                                         101 load
> 
> Did you have a question?
> 
> If you did, it might be:
> 
> 1) can you tell me what I did?
> 2) can you post a high level version of what I did?
> 3) is this done correctly?
> 
> I'm not sure exactly what you're doing.  It's too custom to your Forth.
> You'd have to explain it to me.  If I take a guess, then it looks like you
> tried to define : (colon) without having : (colon) defined.  Defining
> : (colon) and ; (semis) without them already being defined can be done.
> This
> will definately not be for ANS.  I don't know what "now" is or "1301".  I
> can assume 1301 is ENTER or DOCOL.
> 
> 
> Instead of posting : (colon) in terms of : (colon) you might post your
> high-level Forth definition for : (colon).
> 
> It could look something like this:
> 
> : : (CREATE) COMPILE ENTER ] SMUDGE ;
> 
> Then, you'll need to expand the definitions used within until the definition
> is in terms of low-level words or primitives.  It'll also need to work
> interactively.  Next, you'll need to rework it to work without using :
> (colon) and ; (semis).  You need some method to look up and compile words,
> either " ' SMUDGE , " or " BL WORD FIND " in order to compile ENTER
> or it's equivalent.
> 
> 
> If we break it down:
> 
>> createheader :
> 
> This likely creates a dictionary entry for : (colon).  "createheader"
> appears to be your low-level or primitive for CREATE.  Some Forth's
> call it (CREATE).  I.e.,
> 
> (CREATE) :
> 
>>    1301 ,
> 
> Stores 1301 into the definition...  What is 1301?  It might be ENTER or
> DOCOL.  E.g.,
> 
> LIT ENTER ,
> 
> Unfortunately, you've used "1301 ," three times, so "LIT ENTER ," doesn't
> make much sense to me...
> 
>> 32 word createheader find
> 
> BL WORD (CREATE) FIND
> 
> This FINDs the XT for createheader.
> 
>> now 501 ,n 801 ,n execute ,     | compile DROP on the fly
> 
> I guess it "compile[s] DROP on the fly".  This would be to get rid of the
> flag from FIND.
> 
>>    1301 ,
> ...
> 
>> 32 word smudge find
> 
> BL WORD SMUDGE FIND
> 
> This FINDs the XT for SMUDGE
> 
>> now execute ,
> 
> I still don't know what "now" does.  It seems to be used like LIT.  E.g.,
> 
> LIT EXECUTE ,
> 
> If so, then "now execute ," compiles the XT for EXECUTE which will execute
> the XT for SMUDGE.
> 
>>    1301 ,
> 
> ...
> 
>> 32 word ] find
> 
> BL WORD ] FIND
> 
> This FINDs the XT for ]
> 
>> now execute ,
> 
> Still assuming "now" is LIT, then "" compiles the XT for EXECUTE which will
> execute the XT for ].
> 
>>    801 ,
> 
> Stores 801 into the definition...  Either 501 or 801 is DROP, but I'm not
> sure which is which.  It's possible 501 is DROP and 801 is ; (semis).
> 
>>                                                         101 load
> ...
> 
> Even though you used "1301 ," three times, it still seems to be a definition
> for : (colon) without : (colon).  As best I can tell, you did something
> similar to this:
> (CREATE) :
> LIT DOCOL , BL WORD (CREATE) FIND DROP ,
> LIT DOCOL , BL WORD SMUDGE FIND LIT EXECUTE ,
> LIT DOCOL , BL WORD ] FIND LIT EXECUTE , LIT ;S ,
> 
> I suspect I've converted something incorrectly...
> 
> Anyway, I think it should be something closer to this:
> (CREATE) :
> LIT DOCOL ,
> BL WORD (CREATE) FIND DROP ,
> LIT LIT , LIT DOCOL , LIT , ,
> BL WORD SMUDGE FIND DROP ,
> BL WORD ] FIND DROP ,
> 
> But, I'm not an expert on that ...
> 
> 
> Rod Pemberton
> 
> 
> 
> 
> 

It was not a question, just my enjoying in the trying to reduce my Forth 
   interpreter to a minimum.

Your analisys is very detailed considering the specific of my 
implementation (not ANS).
It is not threaded, it is like this:

CALL xt CALL xt CALL xt OPCODE OPCODE OPCODE .... RET
There is not threads (then no ENTERs), i dont kown how it is called.
Every "definitions" are the same, only opcodes; a typical definition is 
a sequence of CALL xt.


createheader :            | create a word header (link, len/flags, name)
     1301 ,                | opcode for CALL
32 word createheader find | correct as you said
now 501 ,n 801 ,n execute ,
     1301 ,
  32 word smudge find
  now execute ,
     1301 ,
  32 word ] find
  now execute ,
     801 ,		   | opcode for RET


"now" and ",n" are a custom words to compile a temporary routine with 
opcodes in a persistent reusable buffer. "Now" reset the compiling index 
and leaves the xt on the stack that execute will calls.
It Is an experiment. This is because i still dont have DROP defined
501 is POP, 801 is RET.
Anyway colon is still defined at that moment.

My future direction is to define as maximum, a block editor then a
a basic compiler with definitions for every OPCODE (24), literals, and 
five or six auxiliary immediate words.


Goodbye

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Thread

colon colon Fanzo <cristianof6@gmail.com> - 2012-07-10 19:58 +0200
  Re: colon colon "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-07-11 04:01 -0400
    Re: colon colon Mark Wills <markrobertwills@yahoo.co.uk> - 2012-07-11 02:01 -0700
    Re: colon colon Fanzo <cristianof6@gmail.com> - 2012-07-11 21:11 +0200
      Re: colon colon "Rod Pemberton" <do_not_have@notemailnot.cmm> - 2012-07-12 05:15 -0400
        Re: colon colon Fanzo <cristianof6@gmail.com> - 2012-07-12 19:58 +0200

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