WG5 Plans for the Use of Type 2 Technical Reports

to Accelerate the Development of Fortran Standards







1.	Summary



At its meeting in Tokyo, 1995/4/17-21, WG5 unanimously decided to adopt a new

approach to the revision of the future editions of the Fortran Standard (IS 1539-1). 

This approach, which was formally approved in Resolution T7 (SC22/WG5 N1116)

involves the use of Technical Reports of Type 2 to define the syntax and semantics of

certain new features in advance of their formal standardization in the hope that this

will enable these features to find their way into Fortran compilers in response to user

demand earlier than would otherwise be the case.



Although the new approach is described in detail in SC22/WG5 N1111, this paper has

been produced at the request of those members of WG5 who were present at the

Tokyo meeting in order to explain the thinking behind this approach to SC22

members, in advance of a request from WG5 for approval of New Work Items to

allow work to proceed in three specified areas.





2.Using Technical Reports to Accelerate Standardization



There are two conflicting problems associated with adding new features to Fortran

when there is perceived to be an urgent market requirement for these features:



	Vendors wish to extend their compilers in order to satisfy the demands

being expressed by their customers (and potential customers);



	Vendors are unwilling to add new features to their compilers in advance

of the final standardization of such features for fear that the standardized

version may differ from that already implemented.



WG5 has decided to make use of Type 2 Technical Reports to resolve this conflict and,

in addition, to enable major new features to undergo a form of "beta test" in advance

of formal standardization.  It is WG5's declared intention that the syntax and

semantics described in such a report will be incorporated unaltered in the next

revision of the International Standard for Fortran, unless experience in the

implementation and use of the features covered by the TR indicates that a change is

required. 



This approach will enable major new features to be developed more quickly than at

present, and will allow for experience with such features (similar to the "beta testing"

of software) before they are finally incorporated in the Standard, while providing a

reasonable guarantee that implementations of the features described in such TRs will

not be wasted effort.

A Type 2 Technical Report is defined as being for use when "the subject in question is

still under technical development or where for any other reason there is the

possibility of an agreement [on publication as an International Standard] at some time

in the future" (JTC1 Directives, 15.2.2).



Furthermore, there is a requirement that, prior to the third year after publication, a

recommendation be made to JTC1 "stating whether the TR should be



		converted to an IS without change;

		revised and published as an IS;

		confirmed for continuation as a TR;

		revised for publication as a revision to the TR;

		withdrawn." (ibid. 15.4.1.2)



Such a TR is, therefore, appropriate for items which are not yet ready to be

standardized but which, it is expected, will be so ready within three years.



WG5's procedures for the future revision of the Fortran Standard may, therefore, be

summarised as follows:



	the method used for the revision of IS 1539:1991, whereby WG5

determined the requirements and delegated the production of a draft CD

to a Primary Development Body (ANSI/X3J3 in the case of Fortran 95),

will be used for the next revision and, in principle, for further revisions

thereafter;



	where a single feature is deemed to satisfy certain criteria, as described in

section 3 of this paper, WG5 will request SC22 to approve a New Work

Item for WG5 for the production of a Type 2 Technical Report specifying

the syntax and semantics of this new feature according to the principles

described below, and will establish a (small) task group to produce a draft

PDTR within a defined period;  it is expected that this group will work

primarily by electronic means, consulting others within the Fortran

community to whatever degree it feels to be necessary and appropriate;



	the features described in any such Technical Reports will be incorporated

in the next revision of the Standard exactly as described in the TR unless

experience in the implementation and use of the feature has identified

errors which need to be corrected. 





3.	The criteria for selecting a feature for definition in Technical Reports



The major criteria which must be satisfied before WG5 will consider developing a

Technical Report for a new language feature are as follows:



	there must be a demonstrable demand for the feature from the Fortran

user community;



	there must be no alternative method of achieving the desired result by

use of existing features of the language which is acceptable to the major

part of the identified user community demanding the feature;



	the feature must be important enough to the identified user community

for a significant proportion to seriously consider converting their

programs to another language if the feature is not available within a

significantly shorter timescale than would be the case if it was only added

at the next revision of the Fortran Standard.



In addition, WG5 must be confident that



	a draft PDTR can be produced within eighteen months of approval of the

relevant New Work Item;



	the Technical Report can be published at least two years before the anti-

cipated publication date of the next full revision of the Standard.





4.	The content of a new feature Technical Report



Every Type 2 Technical Report developed under this process will commence with a

statement along the following lines:



It is the intention of ISO/IEC JTC1/SC22/WG5 that the semantics and

syntax described in this Technical Report shall be incorporated in the

next revision of IS 1539-1 (Fortran) exactly as they are specified here

unless experience in the implementation and use of this feature has

identified any errors which need to be corrected, in which case only those

changes necessary to correct the errors will be made.



This is a strong commitment, but is believed to be essential if vendors are to be

encouraged to implement the features described the the TR in advance of its formal

standardization.



The Technical Report will contain the following three main sections:



	an explanation of why it was felt necessary to define the feature which is

the subject of the Report in advance of the next revision of the Standard;



	a full description of the syntax and semantics of the new feature;



	a complete set of edits to the current Fortran Standard which would be

necessary to incorporate the feature in the Standard;  if no errors are

found during implementation and/or use of the feature then these edits

will be the means by which the feature will be incorporated into the next

revision of the Standard _ other than changes to line numbers, etc, to

accommodate other changes to the language taking place at the same

time.  [Note that the requirement for such a set of edits was deemed

essential by some of the vendors represented at the WG5 meeting which

approved this policy, in order that it is absolutely clear what they should

be implementing.]





5.The method of production of the proposed TRs

 

Since one of the primary criteria for using the Technical Report route, rather than the

main revision route, is that there must be a demonstrable demand for the feature

from the Fortran user community, it is anticipated that the particular user community

will already have one or more representatives amongst the active membership of

WG5, and that one of these individuals, who will, by definition, have a strong

personal interest in the success of the project, will be nominated as Editor of the

Technical Report.



The Editor will be assisted by a (small) number of individuals having a particular

interest and/or expertise in the relevant area of the language, who will, together, form

the task group responsible for producing the draft Technical Report;  this task group is

referred to as the "Development Body" for the TR in the revised WG5 Strategic Plan. 

In general, it is expected that such a task group will always have at least one member

from the Primary Development Body in order that it can have an effective, albeit

informal, means of interaction with the body which will, in due course, be responsible

for incorporating the syntax defined in the TR into the full Standard.  [X3J3, which is

the Primary Development Body for Fortran 95, and the putative Primary

Development Body for Fortran 2000, has supported this approach and proposes to set

up its own subgroups in those areas where a TR is being developed in order to further

develop this interaction.]



At its meeting in Tokyo, WG5 identified three topics which are not in the current

revision of Fortran, which was about to be submitted for CD Registration and

Approval and is expected to be submitted for DIS balloting in early 1996, but which

were deemed to meet the criteria specified above.



Work is currently proceeding in creating the necessary task groups to work on these

topics, and it is planned to submit the corresponding three New Work Item Proposals

for approval by the SC22 Plenary in September 1995.





Miles Ellis

Acting Convenor: WG5