The Princeton INTERCAL Compiler's source code

https://esoteric.codes/blog/published-for-the-first-time-the-original-intercal72-compiler-code

by surprisetalk • 1 year ago

144 49 1 year ago

The INTERCAL satirical language (the original compiler's source code of which is announced as recovered in TFA) was covered in a couple of episodes [0, 1] of the (highly recommended, if I may say) Advent of Computing podcast [2].

  [0] https://adventofcomputing.libsyn.com/website/episode-78-intercal-and-esoterica
  [1] https://adventofcomputing.libsyn.com/website/episode-158-intercal-rides-again-restoring-a-lost-compiler
  [2] https://adventofcomputing.com

lukasb• 1 year ago

I always associated INTERCAL with COME FROM but it turns out that was "invented" separately (although its first implementation was in C-INTERCAL.)

MangoToupe• 1 year ago

I thought come-from was an early scheme primitive. It's pretty trivial to implement and it's a fun trick.

Edit: i am very wrong. i also had no clue it was meant as a joke. I just figured someone had a use case.

vnorilo• 1 year ago

The recent C# feature called interceptors [1] pretty much looks like comefrom from where I stand. Yet everyone talking about it has either been serious, or very good at trolling.

1: https://khalidabuhakmeh.com/dotnet-8-interceptors

pjmlp• 1 year ago

I am completly against them, I think they have re-invented Microsoft Fakes, and PostSharp, only badly.

skissane11• 1 year ago

From your link:

[InterceptsLocation("/Users/khalidabuhakmeh/RiderProjects/ConsoleApp12/ConsoleApp12/Program.cs", line: 3, character: 3)]

they added a language feature which is sensitive to precise line/character offsets in your source code, so the tiniest change to the source code invalidates your code…

I’m speechless. Whatever they are aiming to achieve here, surely there is a more elegant, less ugly way

anyfoo3• 1 year ago

COBOL has an almost-COME-FROM, its called “ALTER” and it changes the destination of a GO TO, but it’s “discouraged” nowadays.

skissane11• 1 year ago

Historically, COBOL has had some rather fascinatingly unusual features-my favourite is OPEN INPUT REVERSED, which opens files for reading backwards-not sure if this was ever in any of the COBOL standards, but it exists in IBM mainframe COBOL, and many implementations on other platforms have copied it from there.

It usually only works for files with fixed length records, and reads the records in reverse sequential order, but the bits/bytes within the record in forward order. In theory, it could be made to work for variable-length record files as well, but I’m not aware of any implementation which does.

The original motivation was to support reading magnetic tapes backwards, so you could write data to a tape, then read it back in without a time-consuming rewind - which was important in the early years of computing, when memory and disk sizes were so small, magnetic tapes were commonly used for temporary storage / work files.

Most tape drives nowadays don’t support reading tapes backwards, even though there are standard SCSI commands defined to do so-but I believe IBM 3592 tape drive series still supports this, as do virtual tape servers targeted at mainframes. The drive physically reads the bits off the tape in reverse order, but then reverses the data before sending it to the computer.

I’m not aware of any other language which supports reading files backwards, other than COBOL. Well, mainframe assembly does, and you can invoke the relevant mainframe IO calls from languages such as C-but COBOL is the only language I know of which has it as a language feature.

Sesse__• 1 year ago

Many languages have exceptions, which are essentially COME FROM.

Duanemclemore• 1 year ago

Probably my single favorite podcast episode ever is the Future of Coding's episode on INTERCAL [0]. At least I think they tried to make it about INTERCAL.

No matter what - a consideration befitting the subject.

[0]https://futureofcoding.org/episodes/064.html

ghssds• 1 year ago

They call it an esoteric language but event-driven programming is basically based on "COME FROM" structures. Shell also extensively uses PLEASE-like fonctionality in the form of SUDO. The syntax of INTERCAL is very clean if we compare it to, say, regex.

anyfoo3• 1 year ago

Not sure about regex. Its syntax is, by definition, regular. (Okay, most regex engines people use aren’t technically fully regular languages anymore, but that just makes things more convenient.)

eru6• 1 year ago

Its syntax is, by definition, regular.

No, not at all. Regexes describe regular languages, but that doesn't mean that their own syntax needs to be a regular language.

Eg many regexes allow parens, so you can have both 'ab|c' and 'a(b|c)'. But if you require your parens to be balanced, that's no longer a regular language.

xxmarkuski• 1 year ago

INTERCAL is presented at the Christmas Lecture in Programming at KIT

breakingcups• 1 year ago

"[...] to English, where the interpreter was once literally another person but is now downgraded to an AI prompt system."

az09mugen2• 1 year ago

Since there is the source now, does someone know what quantity/proportion of "PLEASE" the developer needs to write ?

Because IIRC, if you don't put enough or too much "PLEASE", the compiler won't compile.

moritzwarhier2• 1 year ago

Let's start with: I don't know. Also I can't read this language (BASIC variant?) and am browsing from a phone.

But this line at least outputs the error message:

https://github.com/rottytooth/INTERCAL72/blob/f94e0c8eaaf134...

edit: probably slightly complicated :D

but this makes me wonder if it's related to the source mutliplying some variable/register value by 3 in the error line:

You will need at least 3 lines of code, with one PLEASE statement among them.

(from README)

Just searching "PLEASE" also shows increments and a comparison with a number written in hex... so it should be easy to figure out the intercal "please" halting problem instance, right? :)

az09mugen2• 1 year ago

Thank you so much for the time you took answering that existential question of mine! (And maybe others)

tasty_freeze• 1 year ago

I'm waiting for the self-hosting version of the compiler before I deploy it in my own projects.

The Princeton INTERCAL Compiler's source code

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