Proposal: Standardize the well-known -ROT

Concerning the name -rot

There is only one historically established standard word (other than "-" itself) whose name begins with a minus sign: "-trailing" .

This word name etymology is: "subtract-trailing-spaces"

• the part "spaces" is omitted as obvious (therefore "trailing" becomes a nominalized adjective);
• the verb "to subtract" is represented by the minus sign;

In other known words a leading minus sign also means "to subtract". For example, -trailing-garbage in Forth-2012, -text in Forth-83 Uncontrolled reference words (not a part of the Forth-83 standard word set).

That's why I don't like the name «-rot» for a word that does a reverse rotation.

Other options for naming:

• unrot, from "unrotate";
• derot, from "derotate";
• rev, from "reverse rotate";

Maybe someone can suggest something else?

Other options for naming:

Using rev for this is too short for my tastes. I would rather use rev in the functional programing sense of reversing a list, perhaps as in ( 5 6 7 3 rev -- 7 6 5 ), ( 4 5 6 7 4 rev -- 7 6 5 4 ).

Of the others you suggested, unrot is nicer than derot to my ears as a native English speaker.

I spent some time playing with the idea in Google Gemini, asking if it could think of alternative names. Its first suggestion was unrot; it also suggested b-rot or brot (backwards-rotate). When I pressed Gemini harder to give me a link that uses b-rot, it gave up and pointed me to https://www.forth.org/forth_intro/unrot.htm and gave an excuse that because -rot is so much more common than other spellings, and despite -rot not being a standard word, Gemini could not find references to use of other spellings. Quoting Gemini, "While I learned the concepts and names for many variants of stack operations, my inability to find an existing URL for B-ROT strongly indicates that it is not a public term. It is possible it was used in a private project, a local dialect of Forth, or a closed-source system that is not indexed on the public web.". Then Gemini tried to convince me that Forth-94 had -rot in its optional tools extension word-set (a lie), before conceding that -rot exists in code samples even before Forth-94 existed. At this point, I can't trust whether Gemini is accurate or hallucinating about b-rot.

Gemini did seem to locate a number of URLs to FIGForth and other implementations of ": -rot rot rot ;" with provenance back to the late 70s, even though it could not find evidence of Chuck Moore ever using -rot. Even if we don't like the naming etymology if we were designing from scratch, -rot really does have the most use in existing Forth variations. At some point, we have to decide whether the standards body should be in the business of prescribing new behavior rather than documenting existing behavior.

That said, a page named "unrot" on forth.org vs. the package on theforth.net named "mrot" vs. gforth's pronunciation "not_rot" vs. Jonesforth calling it "nrot" means that even if we do name it -rot, we have to decide what pronunciation we want. And if "unrot" is the most popular pronunciation, how hard would it be to convince implementations like gforth to add unrot as an alias to -rot just for the better etymology?

Less common, I have seen at least one Forth fork that had -roll as the inverse to roll; by your naming, unroll would be a better spelling. However, unroll is a common enough term in compiler optimizations (duplicating the body of a short loop for fewer branches) that it seems like a shame to apply it to the unrelated meaning of "inverse roll". (I actually like your proposal of poke as an inverse to pick; roll requires so much more work than pick that I'm just fine if there is no inverse for roll in the standard)

I agree, of the options considered, the best pronunciation is "unrot", and the best name, I think, is unrot.

Rationale:

• this name is more consistent with the "un-rot" pronunciation and the naming conventions used in other standard word names;
• in general, names without special characters are better than with special characters (if the special character does not have a special meaning);
  • note that a leading minus means "to subtract".

whether the standards body should be in the business of prescribing new behavior rather than documenting existing behavior.

In fact, the standards body is also in the business of prescribing new behavior — there are numerous examples of this. Regarding existing practices, I believe it should not standardize bad practices (including unfortunate/inconsistent names).

In this case, a possible solution is to standardize unrot and add a requirement: "If the Forth system provides the word -rot, that word shall have the same semantics as specified for unrot in this glossary entry".

Standardized in this way, it allows programs to do the following:

[undefined] unrot [if] [defined] -rot [if]
synonym unort -rot
[else]
: unrot rot rot ;
[then] [then]

Or simply:

[undefined] unrot [if]
: unrot rot rot ;
[then]

And if "unrot" is the most popular pronunciation, how hard would it be to convince implementations like gforth to add unrot as an alias to -rot just for the better etymology?

It seems, there is no need to convince implementations, as this word is optional.

As for the word inverse to roll — I agree, there is no need for such a word.

Other options for naming:

In my (perpetually) in-progress implementation, I call it tor, which is literally "rot" reversed :). I do have a synonym for -rot, though. It seems that's the naming most people tend to use.