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Posts Tagged ‘ANSI’

Writing language standards is a cottage industry

August 8th, 2012 No comments

In the beginning programming language standards were written by one country’s National Standards body (e.g., ANSI did C/Cobol/Fortran for the USA and BSI did Pascal for the UK) and other countries were free to write their own version, adopt the existing work or do nothing (I don’t know of any country writing their own version, a few countries sometimes stuck their own front page on an existing document and the majority did nothing; update 4 Dec 2012, thanks to David Muxworthy for pointing out that around 1974 the UK, US, Japan and ECMA were all independently developing a standard for BASIC, by 1982 this had evolved to just ANSI and ECMA).

The UK people who created the Pascal Standard wanted the rest of the world (i.e., the US) to adopt it and the way to do this was to have it adopted as an ISO Standard. The experience of making this happen convinced the folk at BSI that in future language standards should be produced as an international effort within ISO (those pesky Americans wanted changes made to the document before they would vote for it).

During the creation of the first C Standard various people from Europe joined the ANSI committee, X3J11, so they could take part. Initially the US members were not receptive to the European request for a mechanism to handle keyboards that did not contain certain characters (e.g., left/right square brackets) but responded promptly on hearing that those (pesky) Europeans planned to publish an ISO C Standard that would contain those changes to the ANSI Standard needed to support trigraphs; the published ANSI Standard included support for trigraphs. The C ANSI committee were very receptive to the idea of future work being done at the ISO level; Bill Plauger/Tom Plum did a lot of good work to ensure it happened.

The C++ language came along and long story short an ISO committee was set up to create an ISO Standard for it, then Java came along and the Java Study Group failed to become an ISO committee and then various nonspecific language committees happened.

A look at the SC22 web site shows that ISO Standards exist for Forth and ECMAscript (it has not yet been updated to include Ruby) with no corresponding ISO committees. What is going on?

One could be cynical and say that special interests are getting a document of their choosing accepted by ECMA and then abusing the ISO fast track procedure to sidestep the need to setup an international committee that has the authority to create a document of its choosing. The reality is that unless a language is very widely used by lots of people (e.g., in the top five or so most commonly used languages) there are unlikely to be enough people (or employers) willing and able to commit the time and money needed to be actively involved in an ISO Standard committee.

Once a documented has been fast tracked to become ISO Standard any updates to it are supposed to be carried out under ISO rules (i.e., an ISO committee). In practice this is not happening with ECMAscript which continues to be very active (I don’t know what is happening with Forth or how the Ruby people plan to handle any updates), holding bi-monthly meetings; over the years they have fast tracked two revisions to the original fast tracked document (the UK did raise the issue during balloting but nothing came of it, I don’t think anybody really cares).

Would moving the ECMAscript development work from ECMA to ISO make a worthwhile difference? There might be a few people out there who would attend an ISO meeting who are not currently attending ECMA meetings (to join ECMA companies with five or less employees pay an annual fee of 3,500 Swiss francs {about the same number of US dollars} and larger companies pay a lot more) but I suspect the number would not be large enough to make up for the extra hassle of running an ISO committee (e.g., longer ISO balloting timescales).

Production of programming language standards is really a cottage industry that relies on friends in high places (e.g., companies with an existing membership of ECMA or connections into the local country standards’ body) for them to appear on the international stage.

A free pdf that is not the C++ Standard

April 14th, 2012 No comments

One of the most annoying things about working on programming language standards is to see the exorbitant price ISO charge for the final published document created by experts toiling away for free over many years. This practice is unlikely to change.

Once a document has been through a successfully ballot (i.e., accepted for publication as a Standard) ISO has very strict rules about what changes can be made to it prior to actual publication (only typos of the most very innocuous kind can be fixed). Of course programming language committees live on after the publication of a Standard by ISO and it is very useful for them if the document they start deliberating on is one that has had all the typos corrected, not just the really innocuous ones.

The list of typos in the 2011 C++ Standard have been fixed in the freely down loadable committee document N3337 that is not the official C++ Standard, however uncannily similar it may look (no ISO gobbledygook at the front for instance). The equivalent committee document for C is not yet available on the WG14 site.

If you really do need a copy of the C++ Standard the 2011 (i.e., latest) document in pdf form is available for $30 from ANSI; the 2011 C Standard is also available for the same price. Don’t worry about the ANSI version being dated 2012 rather than 2011; National Standards bodies must sell the ISO version at ISO prices but are allowed to publish localized versions for which they can set their own price (so you pay less and get various US specific acronyms and verbiage printed on the front cover).

What I know of Dennis Ritchie’s involvement with C

October 13th, 2011 No comments

News that Dennis Ritchie died last weekend surfaced today. This private man was involved in many ground breaking developments; I know something about one of the languages he designed, C, so I will write about that. Ritchie has written about the development of C language.

Like many language designers the book he wrote “The C Programming Language” (coauthored with Brian Kernighan in 1978) was the definitive reference for users; universally known as K&R. The rapid growth in C’s popularity led to lots of compilers being written, exposing the multiple ways it was possible to interpret some of the wording in K&R.

In 1983 ANSI set up a committee, X3J11, to create a standard for C. With one exception Ritchie was happy to keep out of the fray of standardization; on only one occasion did he feel strongly enough to step in and express an opinion and the noalias keyword disappeared from the draft (the restrict keyword surfaced in C99 as a different kind of beast).

A major contribution to the success of the C Standard was the publication of an “ANSI Standard” version of K&R (there was a red “ANSI C” stamp on the front cover and the text made use of updated constructs like function prototypes and enumeration types), its second edition in 1988. Fans of the C Standard could, and did, claim that K&R C and ANSI C were the same language (anybody using the original K&R was clearly not keeping up with the times).

Ritchie publicly admitted to making one mistake in the design of C. He thinks that the precedence of the & and | binary operators should have been greater than the == operator. I can see his point, but an experiment I ran a few years ago suggested it is amount of experience using a set of operator precedence rules that is the primary contributor to developer knowledge of the subject.

Some language designers stick with their language, enhancing it over the years (e.g., Stroustrup with C++), while others move on to other languages (e.g., Wirth with Pascal, Modula-2 and Oberon). Ritchie had plenty of other interesting projects to spend his time on and took neither approach. As far as I can tell he made little or no direct contribution to C99. As head of the research department that created Plan 9 he must have had some input to the non-Standard features of their C compiler (e.g., no support for #if and support for unnamed structures).

While the modern C world may not be affected by his passing, his ability to find simple solutions to complicated problems will be a loss to the projects he was currently working on.