[kragen]

That sounds like the insight cdiggins based Cat's type system on, but I'm not entirely sure in part because I don't really understand Cat's type system. As an example, though, for the code

    popop    = { pop pop}

Cat infers the parametrically polymorphic typing judgment

    popop    : ('t0 't1 't2 -> 't2) 

where 't2 is the type of the rest of the stack, I guess, and juxtaposition of types is a sort of product operation (noncommutative, but I think associative, and thus perhaps a monoid).

Not sure what you mean about "projectional" — do you mean that "pop" is a "projection" in the relational sense, in that it maps, for example, the stack 3 8 1 (with the top on the left) and the stack 7 8 1 to the same resulting stack state 8 1?

I don't know anything about protein folding.

> I still haven't grokked your whole description of your Lisp reader, I'll have to sleep on it. Is it related in structure to the METAII meta compiler or parser combinators?

Well, I didn't really write much of a description of the reader. It's a recursive-descent predictive parser, same as Probst's reader, and probably most Lisp readers. READ sets up the input pointers and calls (READ), which is ((READ)), which discriminates between lists and atoms (which are numbers) by looking for a "(". If it doesn't find one, it calls READ-NUM to read a number. But if it does, it calls READ-TAIL, which recursively reads the list contents (by calling (READ)) until it finds a ")", then returns back up, consing up the list as it goes. Probst's code works the same way, with the correspondences READ ↔ LISP-LOAD-FROM-STRING, (READ) ↔ LISP-READ-LISP, ((READ)) ↔ _LISP-READ-LISP, READ-NUM ↔ LISP-READ-TOKEN/-NUMBER/-SYMBOL, and READ-TAIL ↔ LISP-READ-LIST.

META II has the similarity that it generates recursive-descent parsers with predictive parsing, but the dissimilarity that it's a domain-specific language for writing parsers. Parser combinators are a technique for embedding any domain-specific parsing language in a general-purpose host language, regardless of what parsing algorithm is used, though Packrat may be the most common choice, and Packrat has certain similarities to recursive-descent parsing.

Is that helpful?

[DonHopkins]

You could follow Lisp's car/caar/caaar cdr/cddr/cdddr cdadar/cadadar/caaddaar naming conventions in Forth ("waiting for the other shoe to drop") or PostScript ("waiting for the other shoe to pop"):

Forth:

    : droop drop drop ;
    : drooop drop drop drop ;
    : droooop drop drop drop drop ;

PostScript:

    /poop { pop pop } def
    /pooop { pop pop pop } def
    /poooop { pop pop pop pop } def

[lebuffon]

This is interesting from the standpoint of the different mentality of Forth coders. If they really needed a fast removal of 4 stack items they would first code what you did.

Then after things were working they might replace droooop with something like this:

( Forth assembler psuedo-code follows)

     code droooop   sp 4 cells addi, next, endcode

One instruction to move the CPU stack pointer. Unthinkable to touch the stack pointer in most other environments but Toto we're not in Kansas. :)

*Next, is the traditional name of the "return to Forth function" in threaded Forth. A return instruction would be used in a native code Forth. Carnal knowledge of the internals is required and used by Forth coders.

[DonHopkins]

In a lot of FORTH implementations, constant numbers like 0, 1, -1 and others are hard coded, not just for speed but also for space: a call to a code word only takes one cell, instead of using two cells with a LIT [value].

Here's some Breshenham line code I first wrote in FORTH (Mitch Bradley's SunForth on a 68k Sun-2 with cg2 graphics board), then translated to 68k code (using the rpn FORTH assembler) -- the FORTH code is commented out before the corresponding assembly code:

https://donhopkins.com/home/archive/forth/cg/line.f

The cg2 board wasn't directly memory mapped -- it had a really weird way of selecting and accessing one row and one column at a time, which was kinda convenient for drawing lines and curves, and ropping blocks around, but nowhere as convenient as direct memory mapped access would have been.

https://donhopkins.com/home/archive/forth/cg/cg.f

I had to reverse engineer it from the map of the registers in this helpful include file:

https://donhopkins.com/home/archive/forth/cg/cg2reg.h

    * To save on virtual address space, we don't map the plane or pixel mode
    * memory (first two megabytes).  However, when calling mmap the user has
    * to add 2M to the desired offset anyway (goofy, huh?).

[kragen]

I never had a cgtwo, myself (because I never used a Sun2). Why do you suppose they used that weird "bank"-switching scheme? It occupied 4MiB of address space anyway!

Why were you in 640×480? I thought the cgtwo was 1152×900 like God intended, and that's what the .h says too.

Was the reason it was important to save virtual address space important that the 68010 ignored the upper 8 bits of virtual addresses? (Helllo, pointer typetag...)

The assembler looks pretty pleasant, though all the 68k operand size suf-, uh, prefixes make the code a bit LONGer than it could be. In gas I really miss having a macro system that can express nested control structures (so I guess I should quit my bitching and write one and use it). I suppose the tests for the IF and WHILE are limited to <, =, <>, >, 0<, 0>, and 0<>?

I'm curious what you think of my analogy upthread between stack-manipulation words and goto. Does it reflect your experience? I'd forgotten you'd done a bunch of Forth stuff.

[DonHopkins]

The wonderful thing about FORTH assemblers is that you have the full power of FORTH to write macros and code generation code with!

That particular assembler had structured control flow like if, while, etc.

It might have actually been a cgone, since the device name was /dev/cgone0. But the header file said cg2. Whatever it was, it was quite slow!

Years later, John Gilmore mentioned that he wrote that .h file with the C structures/unions that mapped out all the device registers.

I bought a copy of Aviator by Curt Priem and Bruce Factor, that ran on my SS2 pizzabox's GX "LEGO: Low End Graphics Option" SBus card (an 8 bit color + 2 bits monochrome overlay plane graphics accelerator):

https://techmonitor.ai/techonology/aviator_15_for_sun_networ...

>AVIATOR 1.5 FOR SUN NETWORKS OPENS UP GRAPHICS WORKSTATION GAMES MARKET. By CBR Staff Writer, 08 Jul 1991.

Not sure why the memory mapping was so weird -- but at least it wasn't as bizarre as the Apple ][! It did have some weird undocumented limitations, like you could only write to the colormap during vertical retrace (which I discovered the hard way -- it didn't seem to work for no apparent reason, except for the occasional times when it did kinda work).

Here's a reference to the cgone device that sounds about right:

http://ftp.uni-bayreuth.de/Digital/alphaserver/archive/magic...

    * SUN120  A Sun Microsystems workstation, model Sun2/120 with
    *   a separate colorboard (/dev/cgone0) and the
    *   Sun optical mouse.  Also works on some old Sun1s with
    *   the 'Sun2 brain transplant'.

http://www.sunhelp.org/faq/FrameBufferHistory.html

    Frame Buffer History Lesson 

    Last Updated: 24th November 1998

    cg1/bw1: device name : "/dev/cgoneX" "/dev/bwoneX"
    The color and monochrome framebuffer of sun100u. 
    It is not a crime not knowing anything about these. (and this was 7 years ago!)

[kragen]

Interesting, thanks!

[kragen]

If you were to implement such a PostScript-based programming language for a Racal PDP-11 clone (or an HP calculator, or a P-code machine), whether in NoCal or in SoCal, I think you'd have to call it FECAL.

If you really wanted to provide such a set of operators for, say, the top N stack items, you could give them systematic names with some distinctive scheme; limiting such stack operators to the top 3, for example, with no more than 2 extra results, you could provide the operators x→ (drop), x→x (nop), x→xx (bad Mexican beer), x→xxx (dupup), xy→ (2drop), xy→x (nip), xy→y (drop again, for consistency), xy→xx (nip dup), xy→xy (nop), xy→yx (exch†), xy→yy (drop dup), xy→xxx (nip dup dup), xy→xxy (dup again), xy→xyx (tuck), xy→xyy, xy→yxx, xy→yxy, xy→yyx, xy→yyy, xy→xxxx, xy→xxxy, xy→xxyx, xy→xxyy, xy→xyxx, xy→xyxy, xy→xyyx, xy→xyyy, xy→yxxx, xy→yxxy, xy→yxyx, xy→yxyy, xy→yyxx, xy→yyxy, xy→yyyx, xy→yyyy, xyz→, xyz→x, xyz→y, xyz→z, xyz→xx, xyz→xy (condescending answer on Stack Overflow), xyz→xz, xyz→yx, xyz→yy, xyz→yz, xyz→zx, xyz→zy, xyz→zz, xyz→xxx (programmers over 18 only), xyz→xxy (Klinefelter syndrome), xyz→xxz, xyz→xyx, xyz→xyy (Jacobs syndrome), xyz→xyz, xyz→xzx, xyz→xzy, xyz→xzz, xyz→yxx, xyz→yxy, xyz→yxz, xyz→yyx, xyz→yyy (bargaining, denial), xyz→yyz, xyz→yzx, xyz→yzy, xyz→yzz, xyz→zxx, xyz→zxy, xyz→zxz, xyz→zyx, xyz→zyy, xyz→zyz, xyz→zzx, xyz→zzy, xyz→zzz, xyz→xxxx, xyz→xxxy, xyz→xxxz, xyz→xxyx, xyz→xxyy, xyz→xxyz, xyz→xxzx, xyz→xxzy, xyz→xxzz, xyz→xyxx, xyz→xyxy, xyz→xyxz, xyz→xyyx, xyz→xyyy, xyz→xyyz, xyz→xyzx, xyz→xyzy, xyz→xyzz, xyz→xzxx, xyz→xzxy, xyz→xzxz, xyz→xzyx, xyz→xzyy, xyz→xzyz, xyz→xzzx, xyz→xzzy, xyz→xzzz, xyz→yxxx, xyz→yxxy, xyz→yxxz, xyz→yxyx, xyz→yxyy, xyz→yxyz, xyz→yxzx, xyz→yxzy, xyz→yxzz, xyz→yyxx, xyz→yyxy, xyz→yyxz, xyz→yyyx, xyz→yyyy, xyz→yyyz, xyz→yyzx, xyz→yyzy, xyz→yyzz, xyz→yzxx, xyz→yzxy, xyz→yzxz, xyz→yzyx, xyz→yzyy, xyz→yzyz, xyz→yzzx, xyz→yzzy, xyz→yzzz, xyz→zxxx, xyz→zxxy, xyz→zxxz, xyz→zxyx, xyz→zxyy, xyz→zxyz, xyz→zxzx, xyz→zxzy, xyz→zxzz, xyz→zyxx, xyz→zyxy, xyz→zyxz, xyz→zyyx, xyz→zyyy, xyz→zyyz, xyz→zyzx, xyz→zyzy, xyz→zyzz, xyz→zzxx, xyz→zzxy, xyz→zzxz, xyz→zzyx, xyz→zzyy, xyz→zzyz, xyz→zzzx, xyz→zzzy, xyz→zzzz (sleep 4), xyz→xxxxx, xyz→xxxxy, xyz→xxxxz, xyz→xxxyx, xyz→xxxyy, xyz→xxxyz, xyz→xxxzx, xyz→xxxzy, xyz→xxxzz, xyz→xxyxx, xyz→xxyxy, xyz→xxyxz, xyz→xxyyx, xyz→xxyyy, xyz→xxyyz, xyz→xxyzx, xyz→xxyzy, xyz→xxyzz, xyz→xxzxx, xyz→xxzxy, xyz→xxzxz, xyz→xxzyx, xyz→xxzyy, xyz→xxzyz, xyz→xxzzx, xyz→xxzzy, xyz→xxzzz, xyz→xyxxx, xyz→xyxxy, xyz→xyxxz, xyz→xyxyx, xyz→xyxyy, xyz→xyxyz, xyz→xyxzx, xyz→xyxzy, xyz→xyxzz, xyz→xyyxx, xyz→xyyxy, xyz→xyyxz, xyz→xyyyx, xyz→xyyyy, xyz→xyyyz, xyz→xyyzx, xyz→xyyzy, xyz→xyyzz, xyz→xyzxx, xyz→xyzxy, xyz→xyzxz, xyz→xyzyx, xyz→xyzyy, xyz→xyzyz, xyz→xyzzx, xyz→xyzzy (Nothing happens), xyz→xyzzz, xyz→xzxxx, xyz→xzxxy, xyz→xzxxz, xyz→xzxyx, xyz→xzxyy, xyz→xzxyz, xyz→xzxzx, xyz→xzxzy, xyz→xzxzz, xyz→xzyxx, xyz→xzyxy, xyz→xzyxz, xyz→xzyyx, xyz→xzyyy, xyz→xzyyz, xyz→xzyzx, xyz→xzyzy, xyz→xzyzz, xyz→xzzxx, xyz→xzzxy, xyz→xzzxz, xyz→xzzyx, xyz→xzzyy, xyz→xzzyz, xyz→xzzzx, xyz→xzzzy, xyz→xzzzz, xyz→yxxxx, xyz→yxxxy, xyz→yxxxz, xyz→yxxyx, xyz→yxxyy, xyz→yxxyz, xyz→yxxzx, xyz→yxxzy, xyz→yxxzz, xyz→yxyxx, xyz→yxyxy, xyz→yxyxz, xyz→yxyyx, xyz→yxyyy, xyz→yxyyz, xyz→yxyzx, xyz→yxyzy, xyz→yxyzz, xyz→yxzxx, xyz→yxzxy, xyz→yxzxz, xyz→yxzyx, xyz→yxzyy, xyz→yxzyz, xyz→yxzzx, xyz→yxzzy, xyz→yxzzz, xyz→yyxxx, xyz→yyxxy, xyz→yyxxz, xyz→yyxyx, xyz→yyxyy, xyz→yyxyz, xyz→yyxzx, xyz→yyxzy, xyz→yyxzz, xyz→yyyxx, xyz→yyyxy, xyz→yyyxz, xyz→yyyyx, xyz→yyyyy, xyz→yyyyz, xyz→yyyzx, xyz→yyyzy, xyz→yyyzz, xyz→yyzxx, xyz→yyzxy, xyz→yyzxz, xyz→yyzyx, xyz→yyzyy, xyz→yyzyz, xyz→yyzzx, xyz→yyzzy, xyz→yyzzz, xyz→yzxxx, xyz→yzxxy, xyz→yzxxz, xyz→yzxyx, xyz→yzxyy, xyz→yzxyz, xyz→yzxzx, xyz→yzxzy, xyz→yzxzz, xyz→yzyxx, xyz→yzyxy, xyz→yzyxz, xyz→yzyyx, xyz→yzyyy, xyz→yzyyz, xyz→yzyzx, xyz→yzyzy, xyz→yzyzz, xyz→yzzxx, xyz→yzzxy, xyz→yzzxz, xyz→yzzyx, xyz→yzzyy, xyz→yzzyz, xyz→yzzzx, xyz→yzzzy, xyz→yzzzz, xyz→zxxxx, xyz→zxxxy, xyz→zxxxz, xyz→zxxyx, xyz→zxxyy, xyz→zxxyz, xyz→zxxzx, xyz→zxxzy, xyz→zxxzz, xyz→zxyxx, xyz→zxyxy, xyz→zxyxz, xyz→zxyyx, xyz→zxyyy, xyz→zxyyz, xyz→zxyzx, xyz→zxyzy, xyz→zxyzz, xyz→zxzxx, xyz→zxzxy, xyz→zxzxz, xyz→zxzyx, xyz→zxzyy, xyz→zxzyz, xyz→zxzzx, xyz→zxzzy, xyz→zxzzz, xyz→zyxxx, xyz→zyxxy, xyz→zyxxz, xyz→zyxyx, xyz→zyxyy, xyz→zyxyz, xyz→zyxzx, xyz→zyxzy, xyz→zyxzz, xyz→zyyxx, xyz→zyyxy, xyz→zyyxz, xyz→zyyyx, xyz→zyyyy, xyz→zyyyz, xyz→zyyzx, xyz→zyyzy, xyz→zyyzz, xyz→zyzxx, xyz→zyzxy, xyz→zyzxz, xyz→zyzyx, xyz→zyzyy, xyz→zyzyz, xyz→zyzzx, xyz→zyzzy, xyz→zyzzz, xyz→zzxxx, xyz→zzxxy, xyz→zzxxz, xyz→zzxyx, xyz→zzxyy, xyz→zzxyz, xyz→zzxzx, xyz→zzxzy, xyz→zzxzz, xyz→zzyxx, xyz→zzyxy, xyz→zzyxz, xyz→zzyyx, xyz→zzyyy, xyz→zzyyz, xyz→zzyzx (Soda Springs), xyz→zzyzy, xyz→zzyzz, xyz→zzzxx, xyz→zzzxy, xyz→zzzxz, xyz→zzzyx, xyz→zzzyy, xyz→zzzyz, xyz→zzzzx, xyz→zzzzy, and xyz→zzzzz. You could certainly argue about the utility of many of these operators individually, not to say their mental risk as attractive nuisances, but their mnemonic value is indisputable.

______

† Where do you get an old PostScript printer? At an exch meet.

[DonHopkins]

I like to perform no-ops that keep the top of the stack fresh:

: NOP DUP SWAP DROP ;

Also:

Q: How many Northern Californians does it take to change a lightbulb?

A: Hella!!!

Q: How many Southern Californians does it take to change a lightbulb?

A: Totally!!!

https://escholarship.org/uc/item/6492j904

http://people.duke.edu/~eec10/hellanorcal.pdf

Hella Nor Cal or Totally So Cal?: The Perceptual Dialectology of California

Mary Bucholtz, Nancy Bermudez, Victor Fung, Lisa Edwards and Rosalva Vargas. Journal of English Linguistics 2007; 35; 325. DOI: 10.1177/0075424207307780

>Abstract

>This study provides the first detailed account of perceptual dialectology within California (as well as one of the first accounts of perceptual dialectology within any single state). Quantitative analysis of a map-labeling task carried out in Southern California reveals that California’s most salient linguistic boundary is between the northern and southern regions of the state. Whereas studies of the perceptual dialectology of the United States as a whole have focused almost exclusively on regional dialect differences, respondents associated particular regions of California less with distinctive dialects than with differences in language (English versus Spanish), slang use, and social groups. The diverse socio linguistic situation of California is reflected in the emphasis both on highly salient social groups thought to be stereotypical of California by residents and nonresidents alike (e.g., surfers) and on groups that, though prominent in the cultural landscape of the state, remain largely unrecognized by outsiders (e.g., hicks).

Extra credit question:

Can you locate the isogloss designating the "101" / "The 101" line?

https://en.wikipedia.org/wiki/Isogloss

https://www.youtube.com/watch?v=zIklKPzND20&ab_channel=Satur...

[kragen]

Don, does your operand stack ever get that... not-so-fresh feeling? Well, what do you do? I use OVER SWAP NIP.

OVER SWAP NIP. Trusted by more hackers.

[sitkack]

xyz→yyz (Rush the stack)

[kragen]

A modern-day hacker

Mean mean code

Today's Chuck Sawyer

Mean mean node

.

Though his stack is not for rent

Don't push dynamic environment

His compiler, a quiet defense

Riding out the stream of events —

The socket

[sitkack]

> Is that helpful?

Absolutely. It made my day. Thank you.

[tsegratis]

Very