LOCALS| and {:

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Date	Fri, 16 Aug 2013 11:59:02 +0100
Subject	LOCALS\| and {:
From	Ian van Breda <igvb@btopenworld.com>
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In the Forth standards proposal a new form of LOCALS| is introduced in the
form of {: .  See the Forth Standards Committee, Forth 200x Draft 11.1, 29th
February, 2012.

I have found the use of LOCALS| invaluable, partly because it greatly
simplifies stack manipulation and partly because it allows intermediate
values to be named, considerably improving documentation and software
maintenance.

Having got used to using LOCALS| it is somewhat confusing to find that names
are reversed in {: .  Although not explicitly stated, it appears that {: :}
is intended to be used at the front of definitions.

It is suggested that LOCALS| also be divided between 'arg' values and 'val'
values.  However, using a | as a separator is more difficult in LOCALS| as
it is also used as a terminator.  An easy way out is to use a || as
separator between arg values and val values.

For example, in the code snippet for my definition, PROCESS-PRODUCTION,
there are three arguments, of which one is a modification of the initial
stack arguments   

    \ Setting derives-lambda flags
        \ Expects: index for enclosing nonterminal; production index; index
        \  for start of production in GrammarTable
: PROCESS-PRODUCTION ( n-index1 n-index2 n-index3 -- )
    ProductionLambdas [[ SWAP ]]           \ Address of production flag
    LOCALS| productionLambda grammarIndex hostIndex || setPattern
        grammarAddress nontermLambda |

Normally, this would need three zeroes preceding the three val variables

    0 0 0  LOCALS| setPattern grammarAddress nontermLambda productionLambda
    grammarIndex hostIndex |

The order for the three val values is immaterial.

The advantages of this:
(1) The number of uninitialized variables are unlimited while the number of
    initialised locals can still be up to eight - plenty for normal use.
(2) There are no limitations on the number of rows allowed for the names of
    the variables - I like to use full names for the variables so often
    cover more that one line.
(3) There are often some stack operations before any LOCALS| are defined.
(4) In its incarnation on the return stack (system-specific), it is faster
    in execution, as the val variables need not be put on the stack
    explicitly.
(5) This brings both {: and LOCALS| into line with each other.
(6) Not all the arguments in a LOCALS| list need be named explicitly.

One definition that is useful is +TO which increments a variable LOCALS|
variable.
            moveCount BufferCount +  TO BufferCount
is better as
            moveCount +TO BufferCount
This is particularly in counting of indefinite loops.

Ian van Breda

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LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-16 11:59 +0100
  Re: LOCALS| and {: "Alex McDonald" <blog@rivadpm.com> - 2013-08-16 12:31 +0100
  Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-16 13:31 +0000
  Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-16 21:50 +0200
  Re: LOCALS| and {: stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-17 08:51 +0000
    Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-18 20:10 +0100
      Re: LOCALS| and {: Coos Haak <chforth@hccnet.nl> - 2013-08-18 23:32 +0200
      Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-18 15:47 -0700
        Re: LOCALS| and {: "Alex McDonald" <blog@rivadpm.com> - 2013-08-19 15:10 +0100
      Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-19 09:46 +0000
        Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-22 20:15 +0100
      Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-19 07:17 -0500
        Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-19 14:18 +0000
          Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-19 10:25 -0500
            Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-19 15:39 +0000
              Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-19 11:26 -0500
            Re: LOCALS| and {: stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-20 11:25 +0000
              Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-20 10:05 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-21 14:38 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-21 11:48 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-21 16:50 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-21 12:18 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-22 12:33 +0000
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-22 15:26 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-22 12:25 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-23 02:24 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 03:12 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-24 01:22 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 02:56 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-23 01:49 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 03:52 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-23 08:10 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 13:00 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-23 13:46 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 03:01 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-24 03:24 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 12:51 -0500
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-25 11:44 -0700
                Re: LOCALS| and {: David Thompson <dave.thompson2@verizon.net> - 2013-08-28 22:27 -0400
                Re: LOCALS| and {: David Thompson <dave.thompson2@verizon.net> - 2013-08-28 22:27 -0400
                Re: LOCALS| and {: "WJ" <w_a_x_man@yahoo.com> - 2013-08-30 02:42 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-22 12:24 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-23 11:50 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 08:13 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-23 13:55 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-23 13:05 -0500
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-24 10:36 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-24 13:05 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-24 22:44 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-25 04:29 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-25 20:15 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-25 15:51 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-25 23:27 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-26 03:19 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-26 20:38 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-27 11:52 -0500
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-28 03:52 +0200
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-28 11:55 -0500
                Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-26 11:36 +0000
                Re: LOCALS| and {: David Thompson <dave.thompson2@verizon.net> - 2013-08-28 22:27 -0400
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-21 10:36 -0700
                Re: LOCALS| and {: stephenXXX@mpeforth.com (Stephen Pelc) - 2013-08-21 17:22 +0000
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-21 12:34 -0500
                Re: LOCALS| and {: mhx@iae.nl - 2013-08-21 23:05 -0700
                Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-22 03:15 -0500
                Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-22 14:49 -0700
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-23 02:07 +0200
                Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-26 20:51 -0700
                Re: LOCALS| and {: Bernd Paysan <bernd.paysan@gmx.de> - 2013-08-27 15:55 +0200
                Re: LOCALS| and {: mhx@iae.nl - 2013-08-27 10:22 -0700
                Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-27 17:33 +0000
                Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-27 23:02 +0000
                Re: LOCALS| and {: mhx@iae.nl - 2013-08-27 22:02 -0700
                Re: LOCALS| and {: Paul Rubin <no.email@nospam.invalid> - 2013-08-27 11:08 -0700
                Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-27 21:16 -0700
                Re: LOCALS| and {: "WJ" <w_a_x_man@yahoo.com> - 2013-08-30 02:56 +0000
              Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-20 20:10 +0000
          Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-20 01:49 +0000
            Re: LOCALS| and {: anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-08-20 07:14 +0000
        Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-21 10:28 +0100
    Re: LOCALS| and {: "Elizabeth D. Rather" <erather@forth.com> - 2013-08-18 10:04 -1000
      Re: LOCALS| and {: Ian van Breda <igvb@btopenworld.com> - 2013-08-19 20:08 +0100
        Re: LOCALS| and {: albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-08-20 01:54 +0000
    Re: LOCALS| and {: Mark Wills <markrobertwills@yahoo.co.uk> - 2013-08-20 02:19 -0700
      Re: LOCALS| and {: Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-08-20 04:37 -0500
  Re: LOCALS| and {: Coos Haak <chforth@hccnet.nl> - 2013-08-17 13:58 +0200
  Re: LOCALS| and {: hughaguilar96@yahoo.com - 2013-08-17 18:49 -0700
  Re: LOCALS| and {: "Ed" <invalid@invalid.com> - 2013-08-23 17:37 +1000

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