The meeting was hosted by Martin Barghorn of the Technical University of Berlin.
- (2.1) DIS, IS 13751, Programming Language Extended APL (Project JTC 1.22.24.01)
-
In December, 1999, the document DIS 13751 was circulated
for re-registration as DIS 13751-2.
All comments from the previous registration had been resolved.
During the first half of the year 2000, the technical work and editing work, in consultation with Geneva, for IS 13751, Programming Language Extended APL, was completed.
We applaud the excellent work of Leigh Clayton of Soliton Associates Limited.
- (2.2) APL Character Repertoire (Projects JTC 1.22.09.02 and JTC 1.22.24.02)
-
The first Committee Draft for this project was submitted and
approved for registration early in the year 2000.
See JTC1/SC22/N3067 or JTC1/SC22/N3082.
The second working draft of the table for this document has been created. It reflects three changes:
- There is a new position the character Quad, now at U+2395.
- Graphic images of the elements in the APL Character Repertoire were adopted, and in some instances adapted, from the work suppled by the Unicode consortium. Our task was made considerably easier, thanks to their generosity.
- The entries in the table have been re-arranged to reflect the ordering implicit in the numbers used in the Universal Character Set (UCS).
There are two project numbers, and possibly, in the end, two nearly identical documents that will contain the same table. It is this table that is the main focus of this work of the APL Character Repertoire project(s). It is intended that the same table accompany the two standards ISO 8485:1999 (APL) and ISO-IEC 13751:2000 (APL Extended), according to this table that links project numbers and standards.
Project number Standard JTC1/SC22/N3067 IS 8485 APL JTC1/SC22/N3082 IS 13751 APL Extended
It was expected that this the final draft would go to press within a month.
The APL Character Repertoire has 131 entries. Of these 131, there are 9 entries where a tack symbol appears, either by itself or in combination with some other symbol, two with a jot, and one each with an underbar, an overbar, and a diaeresis.
There was much discussion about the naming of the nine TACK characters. There was no discussion about any of the other 122 characters, or of their naming. The nine TACK characters are shown and listed shown in this table. Each row of the table show the glyph, the UCS-2 Identifier (U-xxxx), the APL Name, and the name given in UCS-2.
| The Nine APL Tack Symbols | |||
|---|---|---|---|
| Symbol | UCS-2 Identifier | APL Name | UCS Name |
| U+22A2 | Right Tack | RIGHT TACK |
| U+22A3 | Left Tack | LEFT TACK |
| U+22A4 | Down Tack | DOWN TACK |
| U+22A5 | Up Tack | UP TACK |
| U+234A | Up Tack Underbar | A.F.S. DOWN TACK UNDERBAR |
| U+234E | Up Tack Jot | A.F.S. DOWN TACK JOT |
| U+2351 | Down Tack Overbar | A.F.S. UP TACK OVERBAR |
| U+2355 | Down Tack Jot | A.F.S. UP TACK JOT |
| U+2361 | Down Tack Diaeresis | A.F.S. UP TACK DIAERESIS |
Table 1. The Nine Tack Characters
"A.F.S." means "APL FUNCTIONAL SYMBOL"
Table 1 is extracted from the Table for Working Draft 2 of APL Character Repertoire. That Table is based on the public work of Unicode, which we presume to agree with that of IS 10646.
The problem that concerns WG3 is easily seen in the last five entries in the right-most column. There is an internal inconsistency in the naming of the characters known variously as Unicode, and via ISO 10646, UCS-2, and UCS-4.
In order to understand how this situation came about, some explanation is needed.
The APL Working Group started with Set 68, a set of 94 graphic characters for use with workspace interchange. The tack characters there were named according to the the Bosworth Convention, as shown in Table 2 below.
| Two Tack Conventions | ||||||
|---|---|---|---|---|---|---|
| Bosworth Convention | London Convention | |||||
| Up | Up | |||||
| Left | Right | Left | Right | |||
| Down | Down | |||||
Table 2. Two Naming conventions
The APL Working Group assisted SC 2 / WG 2 with the preparation Universal Character Set (UCS), ISO 10646. Since the tack symbols were named by the Bosworth convention in an existing standard, The APL Working Group continued to use those names in its submission.
In some way changes were made. The four tack symbols were renamed (by unknown others who were, perhaps, unfamiliar with the Bosworth convention) by reversing the names Up and Down and reversing the names Right and Left. It might not have been so bad if they had also reversed the names of the five derived tack symbols. At least then the UCS would have had internal consistency.
The APL Working Group, seeing the problem, asked for a fix, and instead of permuting four simple glyphs, UCS left the inconsistency and added 5 footnotes to the derived glyphs.
So now within SC2, UCS is internally inconsistent and there are two different standards that disagree on the names of the four tack characters.
Over time, members of WG3 have recognized that the Bosworth Convention has become less widely accepted, and that most APL users including all of the members of the APL Working Group, were personally using the London Convention. Perhaps this was because of the action of the "unknown others" mentioned above.
In the APL Character Repertoire, the subject of this note, give names that conform to the London Convention, and not the Bosworth Convention. These are seen in the second column of Table 1.
Two Proposed Actions
There are two proposed actions, both of which are necessary to get all relevant matters aligned.-
Proposed Action 1
It is proposed that the APL Working Group (SC22/WG3) ask the UCS Working Group (SC2/WG2) to revise the UCS Names of the five compound symbols (named according to the Bosworth Convention) to agree with the names of the four tack symbols (named according to the London Convention). These changes are as follows:
- U+234A, Up Tack Underbar
- From "APL FUNCTIONAL SYMBOL DOWN TACK UNDERBAR"
- To "APL FUNCTIONAL SYMBOL UP TACK UNDERBAR"
- U+234E, Up Tack Jot
- From "APL FUNCTIONAL SYMBOL DOWN TACK JOT"
- To "APL FUNCTIONAL SYMBOL UP TACK JOT"
- U+2351, Down Tack Overbar
- From "APL FUNCTIONAL SYMBOL UP TACK OVERBAR"
- To "APL FUNCTIONAL SYMBOL DOWN TACK OVERBAR"
- U+2355, Down Tack Jot
- From "APL FUNCTIONAL SYMBOL UP TACK JOT"
- To "APL FUNCTIONAL SYMBOL DOWN TACK JOT"
- U+2361 Down Tack Diaeresis
- From "APL FUNCTIONAL SYMBOL UP TACK DIAERESIS"
- To "APL FUNCTIONAL SYMBOL DOWN TACK DIAERESIS"
- U+234A, Up Tack Underbar
-
Proposed Action 2
It is proposed that The APL Working Group request that Registered Set Number 68 (which uses the Bosworth Convention) be revised so that the four tack symbols be renamed to agree with the the current names for the four tacks in UCS-2 (which uses the London Convention).
References