Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!wuarchive!udel!princeton!pucc!EGNILGES
From: EGNILGES@pucc.Princeton.EDU (Ed Nilges)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Hypercard 2.0
Message-ID: <12213@pucc.Princeton.EDU>
Date: 8 Jan 91 16:32:47 GMT
References: <12208@pucc.Princeton.EDU> <47827@apple.Apple.COM> <12209@pucc.Princeton.EDU> <47854@apple.Apple.COM>
Reply-To: EGNILGES@pucc.Princeton.EDU
Organization: Princeton University, NJ
Lines: 43
Disclaimer: Author bears full responsibility for contents of this article

In article <47854@apple.Apple.COM>, jkc@Apple.COM (John Kevin Calhoun) writes:

>
>But let's not be too hard on its designer.  He got a lot of other things
>right.

You're right on that one.

>
>>                                                      I found that
QUYO to it", for example, works differently when "it" contains "card
>>id nnnnn".
>
>>Where's my Hypercard compiler?
>
>It's in HyperCard, and it's responsible for the slowdown in commands
>such as "go to it".  You can imagine the horror of trying to compile
>a command of this type.  Not very specific at compile time, is it?

Yeah, it's difficult in an interpreted language with DO statements
to in general compile.  IBM recently announced a compiler for the
REXX language which refuses to compile ANY program with INTERPRET
statements (INTERPRET is REXX's analogue to HyperTalk's DO.)  I
claim, however, that this is too restrictive.  If you do flow analy-
sis you can in very many cases predict what the DOne string will
contain.  A trivial example would be

     get "ANSWER" && QUOTE & "NUTS" & QUOTE
     DO it

The flow analysis is identical to what an optimizing compiler needs
to do.  In the original example, GO TO IT, compilation is even
easier as long as you have an execution-time routine for HyperTalk's
GO TO.
>
>The 2.0 HyperTalk compiler, overall, speeds up the execution of 1.0
>scripts.  Naturally, there are tradeoffs, and "go to it" is one of them.

WHAT compiler?  Remember, no manuals.  I have just checked and have
found "comment" and "uncomment" but no "compiler".  I presume that
you do some internal compilation.

Thanks for you assistance.