Comment by zik
25 days ago
As a fan of Algol 68, I'm pretty excited for this.
For people who aren't familiar with the language, pretty much all modern languages are descended from Algol 60 or Algol 68. C descends from Algol 60, so pretty much every popular modern language derives from Algol in some way [1].
Yes, massively influential, but was it ever used or popular?, I always think of it as sort of the poster child for the danger of "design by committee".
Sure it's ideas spawned many of today's languages, But wasn't that because at the time nobody could afford to actually implement the spec. So we ended up with a ton of "algols buts" (like algol but can actually be implemented and runs on real hardware).
Yes, for example UK navy had a system developed in Algol 68 subset.
https://academic.oup.com/comjnl/article-abstract/22/2/114/42...
Used extensively on Burroughs mainframes.
Wow, The Burroughs large system had special instructions explicitly for efficient algol use. You could almost say it was algol hardware. but algol 60 not 68.
https://en.wikipedia.org/wiki/Burroughs_Large_Systems
There is a large system emulator that runs in a browser, I did not get any algol written but I did have way to much fun going through the boot sequence.
https://www.phkimpel.us/B5500/webUI/B5500Console.html
Burroughs used an Algol60 derivative (not '68)
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I would argue C comes from Algol68 (structs, unions, pointers, a full type system etc, no call by name) rather than Algol60
C had 3 major sources, B (derived from BCPL, which had been derived from CPL, which had been derived from ALGOL 60), IBM PL/I and ALGOL 68.
Structs come from PL/I, not from ALGOL 68, together with the postfix operators "." and "->". The term "pointer" also comes from PL/I, the corresponding term in ALGOL 68 was "reference". The prefix operator "*" is a mistake peculiar to C, acknowledged later by the C language designers, it should have been a postfix operator, like in Euler and Pascal.
Examples of things that come from ALGOL 68 are unions (unfortunately C unions lack most useful features of the ALGOL 68 unions. which are implicitly tagged unions) and the combined operation-assignment operators, e.g. "+=" or "*=".
The Bourne shell scripting language, inherited by ksh, bash, zsh etc., also has many features taken from ALGOL 68.
The explicit "malloc" and "free" also come from PL/I. ALGOL 68 is normally implemented with a garbage collector.
C originally had =+ and =- (upto and including Unix V6) - they were ambiguous (a=-b means a= -b? or a = a-b?) and replaced by +=/-=
The original structs were pretty bad too - field names had their own address space and could sort of be used with any pointer which sort of allowed you to make tacky unions) we didn't get a real type system until the late 80s
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> it should have been a postfix operator, like in Euler and Pascal.
I never liked Pascal style Pointer^. As the postfix starts to get visually cumbersome with more than one layer of Indirection^^. Especially when combined with other postfix Operators^^.AndMethods. Or even just Operator^ := Assignment.
I also think it's the natural inverse of the "address-of" prefix operator. So we have "take the address of this value" and "look through the address to retreive the value."
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C's «static» and «auto» also come from PL/I. Even though «auto» has never been used in C, it has found its place in C++.
C also had a reserved keyword, «entry», which had never been used before eventually being relinquished from its keyword status when the standardisation of C began.
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That is indeed correct. Kernighan in his original book on C cited Algol 68 as a major influence.
> I'm pretty excited for this
Aside from historical interest, why are you excited for it?
Personally, I think the whole C tangent was a misstep and would love to see Algo 68 turn into Algo 26 or 27. I sort of like C and C++ and many other languages which came, but they have issues. I think Algo 68 could develop into something better than C++, it has some of the pieces already in place.
Admittedly, every language I really enjoy and get along with is one of those languages that produced little compared to the likes of C (APL, Tcl/Tk, Forth), and as a hobbyist I have no real stake in the game.
I wonder about what you think is wrong with C? C is essentially a much simplified subset of ALGOL68. So what is missing in C?
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Whilst I think that C has its place, my personal choice of Algol 26 or 27 would be CLU – a highly influential, yet little known and underrated Algol inspired language. CLU is also very approachable and pretty compact.
Consider exploring Ada 2022 as a capable successor to Algol. Its well supported in GCC and scales well from very small to very large projects. Some information is at https://learn.adacore.com/ and https://alire.ada.dev/
Is like to order a complementary question to the sibling one. What are you going to add to (/remove from?) Algol 68 to get Algol 26?
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Wouldn't that be some form of Pascal?
I've actually been toying with writing an Algol 68 compiler myself for a while.
While I doubt I'll do any major development in it, I'll definitely have a play with it, just to revisit old memories and remind myself of its many innovations.
If PL/I was like a C++ of the time, Algol-68 was probably comparable to a Scala of the time. A number of mind-boggling ideas (for the time), complexity, an array of kitchen sinks.
It certainly has quite a reputation, but I suspect it has more to do with dense formalism that was quite unlike everything else. The language itself is actually surprisingly nice for its time, very orthogonal and composable.
Finally.