ISO/IEC JTC = 1/SC22

Programming languages, their environments = and system software interfaces

Secretariat: U.S.A. = (ANSI)

ISO/IEC JTC 1/SC22 = N3751

TITLE:

Letter from JTC 1/SC 22 to JTC 1/SC 2 = Requesting that JTC 1/SC 2 Consider Putting Specification of the Character = Repertoire for Identifier on the SC 2 Programme of Work =

DATE ASSIGNED:

2004-06-18

SOURCE:

SC 22 = Secretariat

BACKWARD = POINTER:

DOCUMENT TYPE:

Other (Defined)

PROJECT NUMBER:

STATUS:

This letter has been sent to the Chair and = Secretary of JTC 1/SC 2 from the Chair and Secretary of JTC 1/SC 22 on behalf of = JTC 1/SC 22. The Japanese National Body incorporated comments received = from N 3725.

ACTION = IDENTIFIER:

FYI

DUE DATE:

DISTRIBUTION:

TEXT

CROSS = REFERENCE:

N3673, N3725

DISTRIBUTION = FORM:

Def

Address reply = to:

ISO/IEC JTC 1/SC22 = Secretariat

Sally = Seitz

ANSI

25 West 43rd = Street

New York, NY 10036

Telephone: (212) = 642-4918

Fax: &n= bsp; (212) 840-2298

Email: = sseitz@ansi.org

_______________________end of cover page, beginning of = document_______________

18 June 2004

Dear Dr. Shibano = and Ms. Kimura,

SC 22 would like = to make a request to SC 2/WG 2, such that whenever SC 2/WG 2 adds new characters = to ISO 10646, SC 2/WG 2 also specifies those new characters that would be = acceptable as identifiers.

The background of = the request:

1) Currently TR = 10176 (The guidelines for preparation of programming language standards), a = project of SC 22, provides a guideline for character repertoire to be allowed for = identifiers in Annex A (Recommended extended repertoire for user-defined = identifier). SC 22 has been revising Annex A of TR 10176 following the revisions of = ISO/IEC 10646 in order to be synchronized with character property of the Unicode = standard. However, SC 22's revision work could not be started before the = publication of the revised edition of ISO/IEC 10646, therefore the content of Annex A = of TR 10176 is not in agreement with the latest edition of ISO/IEC 10646. If = SC 2 specifies character repertoire for identifiers, the technical contents = of TR 10176 would become synchronized with the future editions of ISO/IEC = 10646.

2) The work of = identifying extended characters is likely to have broad interest to JTC 1 = subcommittees, such as SC 7, SC 22, SC 23, SC 25, SC 28, SC 31, SC 32, SC 34, SC 35, = and SC 36. It is recommended that this work be circulated at the JTC 1 level = so that JTC 1 subcommittees may be better informed of these SC 2 activities, = and so that JTC 1 subcommittees may harmonize their work with the SC 2 = activities.

SC 22's = consideration to be kept in mind:

In addition to = identifying extended identifier characters, it may be important for many ICT = applications to know what characters are also considered extended digit characters, = extended letter characters, and other classes of extended special = characters.

In prior work on = extended identifiers, knowledgeable experts provided advice and guidance that = helped properly classify characters. It would be extremely helpful to capture = this knowledge in a "rationale/criteria annex" or a companion = technical report so that users of these classifications could be better informed = about the intended uses, the special circumstances, the limitations, and so = on.

While it is not = necessarily a classification function, certain relationships are important for = common operations on identifiers, such as the familiar upper-lower case usage = in Latin letters (e.g., leading capitals, "camel case", etc.). It has = been discovered that additional character transformations for identifiers = are in use in non-Latin scripts in ICT applications (e.g., full vs. half width for Japanese identifiers). It would be helpful if the character set experts = in SC 2 could identify some of these popular conventions so that they could be = better understood and processed more consistently in ICT = environments.

SC 22 would like = to ask SC 2/WG 2 to specify those characters which they believe are suitable for identifiers, leaving each programming language standard (SC 22 and = other SCs and work programs generally) free to specify its own = identifier-character list after considering the tradeoffs between its requirements and the = advantages of a consistent, single, identifier specification in the same manner as = the current TR 10176 recommends that programming language standards can = extend or restrict the identifier character list.

SC 22 would like = to request that SC 2 respond to this question by August 2004 if = possible.

On behalf of JTC = 1/SC 22,

John Hill, = Chairman

Sally Seitz, = Secretary

Sally = Seitz

Program = Administrator

ANSI

25 = West 43rd Street

New = York, NY 10036<= /p>

Phone: (212) 642-4918

Fax: (212) 840-2298