The Algol 68 Genie project

I vaguely remember something about a compiler (probably the Algol 68 compiler) with the wierdest bug that I have ever heard about a compiler: In certain months of the year, it had problems with compiling certain programs and students were adviced to try again a month later. The bug was never found.

Re: The Algol 68 Genie project

#4

Post by vincent-manis » Tue, Jan 03, 2023, 11:42 PM UTC

This really does take me back, as I was a graduate student under J.E.L. Peck (though I didn't actually work on his compiler) back around 1970. I have always felt that ALGOL 68 (he insisted on the block caps) was undervalued as a programming language; it was harmed by its impenetrable specification (two-level grammars are a clever idea, but horrible for actual understanding), and the absolutist ideas of the compiler writers (the standard complaint about any short-cuts was “what if we have a left bracket, 50 pages of code, and the matching right bracket”, as though that was actually something somebody would do.

The lack of a concrete syntax also harmed it: different implementations spelled the “begin” keyword as BEGIN, 'BEGIN, and .BEGIN. Goodbye portability!

And finally, ALGOL 68 learned from ALGOL 60's failure to include an I/O library: they did a splendid job on their transput library. Unfortunately, it is record-oriented (as were most mainstream OS file systems of the time) at just the moment when Unix was about to popularize the byte-stream file abstraction.

I really wish that an ALGOL 68-style language had been successful, even given these mistakes (when you do a radical rethink of programming languages, you are bound to make mistakes). There was even at least one machine-oriented ALGOL-68 style language named Mary, which might have been a good replacement for C. It's good to see that at least some work on implementation continues.

Re: The Algol 68 Genie project

#5

Post by Taniwha » Wed, Jan 04, 2023, 12:00 AM UTC

vincent-manis wrote: post #4

This really does take me back, as I was a graduate student under J.E.L. Peck (though I didn't actually work on his compiler) back around 1970. I have always felt that ALGOL 68 (he insisted on the block caps) was undervalued as a programming language; it was harmed by its impenetrable specification (two-level grammars are a clever idea, but horrible for actual understanding), and the absolutist ideas of the compiler w…

I'm sure you remember that at the time it was written people were still trying to figure out what a computer language should look like - also most people at the time only had upper case (card punches)

The whole how do we use keywords in compilers (and in multiple languages)? how do we represent types? was all still something people were thinking through - in retrospect the two cases thing for parts of the language was a mistake, as was the 2 level grammar spec

Re: The Algol 68 Genie project

#6

Post by dang » Wed, Jan 04, 2023, 12:31 AM UTC

Url changed from https://jmvdveer.home.xs4all.nl/en.download.algol-68-genie-c..., which points to this.

Re: The Algol 68 Genie project

#7

Post by Koshkin » Wed, Jan 04, 2023, 1:12 AM UTC

Algol 68 was/is a magnificent language, and the experience of reading the Revised Report from cover to cover is unforgettable.

The logical structure of the language was driven to the extreme: I vaguely remember that

  int a;

was merely an abbreviation of something like

  ref int a = new int;

Re: The Algol 68 Genie project

#8

Post by vincent-manis » Wed, Jan 04, 2023, 1:49 AM UTC

Taniwha wrote: post #5

vincent-manis wrote: post #4

This really does take me back, as I was a graduate student under J.E.L. Peck (though I didn't actually work on his compiler) back around 1970. I have always felt that ALGOL 68 (he insisted on the block caps) was undervalued as a programming language; it was harmed by its impenetrable specification (two-level grammars are a clever idea, but horrible for actual understanding), and the absolutist ideas of the compiler w…

I'm sure you remember that at the time it was written people were still trying to figure out what a computer language should look like - also most people at the time only had upper case (card punches) The whole how do we use keywords in compilers (and in multiple languages)? how do we represent types? was all still something people were thinking through - in retrospect the two cases thing for parts of the language wa…

There were literally hundreds of languages around when the ALGOL 68 effort started, so there was lots of experience to draw from.

Both the lack of concrete syntax and the 2-level grammars were disputed at the time, and one might remember that Wirth and Hoare designed ALGOL W as a reaction against the ALGOL 68 effort. (I liked both languages, silly me.)

My original comment was not intend as snark against the ALGOL 68 designers, but rather to point out that the language had a lot going for it, even with these serious flaws. But as is often the case, we learn more from mistakes than successes.

Re: The Algol 68 Genie project

#9

Post by int_19h » Wed, Jan 04, 2023, 2:08 AM UTC

vincent-manis wrote: post #4

This really does take me back, as I was a graduate student under J.E.L. Peck (though I didn't actually work on his compiler) back around 1970. I have always felt that ALGOL 68 (he insisted on the block caps) was undervalued as a programming language; it was harmed by its impenetrable specification (two-level grammars are a clever idea, but horrible for actual understanding), and the absolutist ideas of the compiler w…

> The lack of a concrete syntax also harmed it: different implementations spelled the “begin” keyword as BEGIN, 'BEGIN, and .BEGIN. Goodbye portability!

It's not all downsides, though. Due to Algol (both 60 and 68) treating keywords as abstract symbols, it made it possible to translate those keywords to other languages. This was done in USSR, for example, and made Algol much more accessible to programmers there.

(I know there were similar experiments elsewhere in Europe; not sure if they were quite as successful, though.)

Re: The Algol 68 Genie project

#10

Post by int_19h » Wed, Jan 04, 2023, 2:09 AM UTC

vincent-manis wrote: post #8

Taniwha wrote: post #5

Earlier quoted context omitted.

I'm sure you remember that at the time it was written people were still trying to figure out what a computer language should look like - also most people at the time only had upper case (card punches) The whole how do we use keywords in compilers (and in multiple languages)? how do we represent types? was all still something people were thinking through - in retrospect the two cases thing for parts of the language wa…

There were literally hundreds of languages around when the ALGOL 68 effort started, so there was lots of experience to draw from. Both the lack of concrete syntax and the 2-level grammars were disputed at the time, and one might remember that Wirth and Hoare designed ALGOL W as a reaction against the ALGOL 68 effort. (I liked both languages, silly me.) My original comment was not intend as snark against the ALGOL 68…

When I was reading the ALGOL working group archives, the impression that I got was that Wirth and Hoare designed (what would later be called) ALGOL W as a candidate proposal for ALGOL X, the latter being what would eventually evolve into ALGOL 68.