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Re: "Recognizing" a parser generator (and a compiler compiler)

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Elizabeth D. Rather wrote:
> On 5/8/17 8:50 PM, Alex wrote:
> > On 5/9/2017 05:07, Joel Rees wrote:
> >>
> >>>> I have <BUILDS, I mean, CREATE DOES>
> >>>>
> >>>> (Which I was struggling with over the weekend, but that's
> >>>> another story not worth posting about.)
> >>>>
> >>>> Each word in Forth defines its own syntax. Each word in Forth has
> >>>> its own attached semantics.
> >>>
> >>> That's not strictly true. Words like IF pass semantic clues to
> >>> their corresponding ELSE THEN on the stack.
> >>
> >> No, it is true. ELSE and THEN are syntactically and semantically
> >> parts of IF. You haven't properly parsed your IF until you've parsed
> >> the optional ELSE and the trailing THEN.
> >
> > We're going to have to disagree. They have compile-time semantics that
> > are different from their run-time semantics for one.
>
> Joel, the thing you have to realize here is that there is *zero*
> "syntactic" connection between IF, ELSE, and THEN. Each is interpreted
> in turn and does whatever it's defined to do. That is, IS compiles
> something followed by a reserved cell usually containing zero, and
> leaves that address on the stack. This location will normally be filled
> in subsequently by either ELSE or THEN, but each of those words is
> completely independent and has no real syntactic connection.
> ...

ANS defines syntax through the use of 'orig', 'dest', 'of-sys' etc whose
sole purpose is to restrict what you may mix & match legally, if not
practically.

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"Recognizing" a parser generator (and a compiler compiler) Joel Rees <joel.rees@gmail.com> - 2017-05-07 19:29 -0700
  Re: "Recognizing" a parser generator (and a compiler compiler) hughaguilar96@gmail.com - 2017-05-07 21:57 -0700
    Re: "Recognizing" a parser generator (and a compiler compiler) Alex <alex@rivadpm.com> - 2017-05-08 09:55 +0100
  Re: "Recognizing" a parser generator (and a compiler compiler) Alex <alex@rivadpm.com> - 2017-05-08 09:41 +0100
    Re: "Recognizing" a parser generator (and a compiler compiler) Joel Rees <joel.rees@gmail.com> - 2017-05-08 21:07 -0700
      Re: "Recognizing" a parser generator (and a compiler compiler) Alex <alex@rivadpm.com> - 2017-05-09 07:50 +0100
        Re: "Recognizing" a parser generator (and a compiler compiler) "Elizabeth D. Rather" <erather@forth.com> - 2017-05-08 21:39 -1000
          Re: "Recognizing" a parser generator (and a compiler compiler) "HAA" <someone@microsoft.com> - 2017-05-10 15:27 +1000
            Re: "Recognizing" a parser generator (and a compiler compiler) Alex <alex@rivadpm.com> - 2017-05-10 08:21 +0100
              Re: "Recognizing" a parser generator (and a compiler compiler) "HAA" <someone@microsoft.com> - 2017-05-10 18:15 +1000
          Re: "Recognizing" a parser generator (and a compiler compiler) Joel Rees <joel.rees@gmail.com> - 2017-05-10 00:53 -0700
            Re: "Recognizing" a parser generator (and a compiler compiler) Alex <alex@rivadpm.com> - 2017-05-10 08:59 +0100
      Re: "Recognizing" a parser generator (and a compiler compiler) mhx@iae.nl - 2017-05-10 02:52 -0700
        Re: "Recognizing" a parser generator (and a compiler compiler) albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-05-10 11:59 +0200
          Re: "Recognizing" a parser generator (and a compiler compiler) Joel Rees <joel.rees@gmail.com> - 2017-05-10 05:46 -0700
          Re: "Recognizing" a parser generator (and a compiler compiler) mhx@iae.nl - 2017-05-10 05:48 -0700

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