Magic Words alternatives

xorxes' Version

Magic words are all cmavo that have some interaction with words as words irrespective of their function. These are SI SA SU ZO ZOI LOhU LEhU ZEI BU and FAhO. (BAhE, even though it can modify any word, is not a magic word, because it doesn't affect the function of the word it modifies.)

Meta-Rule

1. Magic words are processed left-to-right.

1. Y is not a word (i.e. it is considered whitespace) for the purposes of these definitions.

Proposed definitions

1. ZO turns the following word into a quoted word, which behaves as a member of KOhA.

1. LOhU turns all following Lojban words up to a LEhU into a LOhU-quote, which behaves as a member of KOhA.

1. LEhU terminates a LOhU-quote. It is never elidable.

1. ZEI combines the preceding word, quoted word, LOhU-quote, ZEI-lujvo, lerfu word, or ZOI-phrase together with the following word into a ZEI-lujvo, which behaves as a member of BRIVLA.

1. BU turns the preceding word, quoted word, LOhU-quote, ZEI-lujvo, lerfu word, or ZOI-phrase into a lerfu word, which behaves as a member of BY.

1. ZOI uses the following word as a delimiting word, and turns anything that follows until the delimiting word is found again into a ZOI-phrase, which behaves as a member of KOhA.

1. SI erases the preceding word, quoted word, LOhU-quote, ZEI-lujvo, lerfu word, or ZOI-phrase. The construct becomes invisible to the rest of the text.

1. SA erases the preceding text back until it sees a word of the same selma'o as the word that follows SA, which replaces it. (Words that have been turned into a quoted word, a LOhU-quote, a zei-lujvo, a lerfu word, or a delimiter in a ZOI-phrase are invisible to SA, but the magic word in those constructs is visible.) The construct becomes invisible to the rest of the text.

1. SU erases all words back to the beginning of text. The construct becomes invisible to the rest of the text.

1. FAhO terminates the text, absorbing preceding words until the remaining text is grammatical.

Marking Words

• BAhE marks the following word but does not change its nature. The construct behaves just as that word by itself.
• Attitudinals (UI and CAI cmavo) mark the previous word, quoted word, LOhU-quote, ZEI-lujvo, lerfu word, or ZOI-phrase, but do not change its nature. Attitudinals do not blend into a single word with the word they modify, but remain as separate words for the purposes of magic words that come after them.

• DAhO, FUhE, and FUhO are the same as UI, but do not absorb a following NAI.

Comparison

A comparison between this method and Robin's method below. Bear in mind that all of these differences could theoretically be rectified by exceptions to one or the other method.

Subject Phrase	LTR	Precedence
broda .y. bu	The letter broda	broda + The letter y
zoi si stuff si	"stuff"	Error (first si erases the zoi)
da zoi sa da joi de	Unclosed zoi	da joi de
da zei fa'o	Lujvo of da and fa'o	Error (unclosed zei)
lo'u co co zo le'u co le'u	Error ("co le'u" outside of quotes)	"co co le'u co"
zoi si doi do	Uclosed zoi	doi do
zo da si	Nothing	Open zo
zo da si si	Error (too many si)	Nothing
da zei de bu	Letter da type of de	Error
bu zei de	Error (nothing for bu to use)	bu type-of de
zo bu zei de	"bu" type-of de	Error
broda zei brode si brodi	brodi	broda zei brodi
zei zei zei	Error	Error
da zei zei	da type-of zei	Error
lo'u co co co le'u bu	The letter "co co co"	Error
lo'u co co co le'u si bo le'u	Error (bare bo)	lo'u co co co bo le'u
broda ba'e si	nothing (but emphatically!)	broda
broda ba'e da si da	broda da	broda da
zo da bu	The letter "da"	Error
zoi zoi That letter that you use between a user id and a host name in an e-mail address zoi bu	@	Error
broda brode si bu	The letter broda	Same
zoi zoi stuff zoi si	Nothing	An open zoi quote
zoi zoi lots of stuff zoi si si si si	Error (too many si)	Nothing
zoi zoi lots of stuff zoi sa zoi si	Open zoi	Nothing

John Cowan's Version

1. ZO turns the following word into a word of selma'o any-word.

1. LOhU turns all following Lojban words up to but not including a LEhU into a single word of selma'o any-string.

1. LEhU terminates a LOhU-quote. It is never elidable.

1. ZEI turns the preceding word and the following word into a member of BRIVLA.

1. BU turns the preceding word into a word of selma'o any-word; such a word followed by a BU has the same grammatical function as a member of BY.

1. ZOI uses the following word as a delimiting word and turns it into a word of selma'o any-word. All words that follow until the delimiting word is found again are turned into a word of selm'ao any-string; the second delimiting word is turned into a word of selma'o any-word.

1. SI erases the preceding word. The construct becomes invisible to the rest of the text.

1. SA erases the preceding text back until it sees a word of the same selma'o as the word that follows SA, which replaces it. Words whose selma'o has been changed to any-word or any-string are invisible to SA.

1. SU erases all words back to the beginning of text. The construct becomes invisible to the rest of the text.

1. FAhO terminates the text, absorbing preceding words until the remaining text is grammatical.

Robin's Version

This document was originated to provide a clearing house for discussion related to the BPFK Magic Words checkpoint, as well as a place safer than /tmp to store my ongoing description of the magic word interactions, which here follows.

Magic words are all cmavo that interact directly with the nature of the speech stream, so SI SA SU ZO ZOI LOhU LEhU ZEI BU BAhE FAhO.

The two documents that were used to construct this page are grammar.300 (which is a plain text document, and really should be renamed to have .txt after it) and RefGram Chapter 19, section 16.

It is worth noting that these two documents contradict each other on many points. In particular, the order of operations is substantially different (grammar.300 handles zoi before lo'u...le'u, for example).

Outstanding Questions

• Is nested lo'u...le'u allowed?
  • Not really, but lo'u has no effect and we allow "zo le'u".

• Does zoi function in lo'u...le'u?
  • No. If you need to quote a broken zoi, use another zoi.

• What does BAhE+BU do?
  • Just empasizes the BU.

• The red book claims that UI cmavo can't mark BU. What's up with that?
  • I have no idea, but I'm ignoring it. UI can mark anything that doesn't grab it.

• What do we do about ZOI, SI and SA interactions? Is SI allowed as a ZOI delimiter? Does SI after a ZOI clause erase the whole thing?
  • SI, SA and SU are not allowed ZOI delimiters. 4 SI for ZOI erasure from outside. SA+ZOI+SI works. ZOI+SI == nothing.

• Does SU go back to the last NIhO, LU, TUhE, or TO (as grammar.300 claims) or the beginning of input (as the Red Book claims)?
  • The latter; SA can be used for the other things, and if SU works the former way there is no way to unequivocably erase to the beginning of input.

• grammer.300 claims that ZEI works on ZOI, ZO and LOhU...LEhU clauses. I'm pretty sure this is just a YACC side effect; it certainly seems amazingly ridiculous to me. If anyone disagrees, let me know.
  • It doesn't do any harm, and allows certain useful things (like ZEI lujvo with the various words that ZEI can't bind to in them).

Meta-Rules

1. Magic words lay claim to, or "grab", other words, with varying effects.

1. Magic word grabbing proceeds by an order of precedence. The effect of a magic word can be to prevent the operation of another magic word (zo in particular) in which case the word that has been so grabbed no longer is allowed to grab other words.

1. No two magic words may grab the same word, unless the interaction between those two magic words has been clearly defined. Any attempt to do so is an error.

Magic Words Handling

(based on C16 S19 of the RefGram)

In order of precedence. selma'o names used throughout. + means "a member of the selma'o to the left of the + followed immediately by a member of the selma'o to the right of the + (ignoring words taken out of the equation by previous steps)". For example, "ZO+LEhU" means a string like "zo le'u" (since both of these are currently (6 Nov 2004) single member selma'o). Just to be pedantic, "any word" and similar refer only to valid Lojban words unless the text explicitely states otherwise.

1. Y is completely ignored (i.e. considered whitespace) except before BU.

1. ZOI cmavo use the following word as a delimiting word, no matter what it is, execept Y (which is ignored); and SI, SA and SU (which erase it).

1. ZO quotes the following word, no matter what it is, except Y. Words quoted with ZO lose their grammatical functions.

1. FAhO terminates the word or text stream unequivocably, unless quoted with ZO, ZOI or LOhU...LEhU.

1. LOhU quotes all following Lojban words up to a LEhU (but not a ZO+LEhU; this is to allow nested LOhU...LEhU quotes inside a LOhU...LEhU, so you can talk about mistakes you made that include a previous error quote). Except for the ZO+LEhU case (which should be read as simply LEhU inside a LOhU...LEhU quote) all Lojban words within a LOhU...LEhU quote are read without any grammar and have no grammatical effects.

1. LEhU is ungrammatical except at the end of a LOhU quotation and after ZO.

1. SI erases the preceding word unless it is a ZO. Y is ignored.

1. SA erases the preceding word and other words, unless the preceding word is a ZO. SA erases back until it sees a word of the same selma'o as the word that follows SA. The previous same-selma'o word is itself erased. Y is ignored for selma'o matching purposes.

1. SU erases itself and all words back to the beginning of the current conversation for the speaker that says it. If spoken twice, it also erases the other speaker's words. In computer input cases SU, in general, erases itself and all words to the beginning of the input (as most computer input cases cannot distinguish between speakers).

1. ZEI combines the preceding and the following word into a lujvo. For words to its left, it does not affect SI, SA, and SU (it affects whatever is to the left after the erasing is done; if nothing is left an error result); ZO and LOhU (which quote it); ZOI (which uses it as a delimiter); BAhE and Y (which it skips); ZEI (which would lead to grouping issues, and hence is an error to attempt); and FAhO (which makes no sense because the stream ends at the FAhO). For words to its right, it does not affect SI, SA, and SU (which erase it); BAhE and Y (which it skips); ZEI (which would lead to grouping issues, and hence is an error to attempt); and FAhO (which results in an error). ZO, ZOI and LOhU...LEhU clauses are attached to the ZEI lujvo in their entirety. BAhE effects ZEI as usual, so ZEI skips over any preceeding BAhE cmavo to affect the word before them.

1. BU makes the preceding word into a lerfu word, except for ZO, ZEI and LOhU (which quote it), ZOI (which uses it as a delimiter); LEhU (which would result in bizarrely re-opening the LOhU...LEhU, and hence is an error); SI, SA and SU (it affects whatever is to the left after the erasing is done; if nothing is left an error results); BAhE (which it skips); BU (which would lead to grouping issues, and hence is an error to attempt); and FAhO (after which anything, including BU, is ignored). Note that Y is specifically included. BAhE effects BU as usual, so BU skips over any preceeding BAhE cmavo to affect the word before them. Multiple BU may be used in succession, in which case a new letteral is formed for each additional BU (i.e. "broda bu" is a different letteral from "broda bu bu"). However, "bu bu" by itself is illegal.

Marking Words

Some words are almost, but not quite, magic words, in that they mark and affect nearby words, but do not change the special effects of other magic words. Hence they don't really fall in to the magic word precedence list.

• BAhE marks the following word, except for SI, SA and SU (which erase it), or unless it is preceded by ZO (which quotes it) or ZOI (which uses it as a delimiter). Multiple BAhE cmavo may be used in succession, in which case they all affect the next non-BAhE word. BAhE skips Y as usual.
• Attitudinals (UI and CAI cmavo) mark the previous word, except for SI, SA and SU (the attitudinal marks whatever is to the left after the erasing is done, if anything); ZO, LOhU or ZEI (which quote it); ZOI (which uses it as a delimiter); BAhE (BAhE marks the attitudinal, which in turn marks the word before the stream of BAhE); Y (which is ignored); FAhO (which there can be nothing to the right of). Attitudinals are permitted following any word of the grammar, without interfering with that word's grammatical function, or causing any effect on the grammatical interpretation of any other token in the text. Multiple UI cmavo may be used in succession. They may also be used at the beginning of text. A following NAI is made part of the attitudinal.

• DAhO, FUhE, and FUhO are the same as UI, but do not absorb a following NAI.

Special SI and SA Cases

SI gets very complicated in a few cases, so here we go. Some SA notes here too.

• SI has no effect inside LOhU...LEhU or after ZO (or inside a ZOI quote, of course).
• Multiple SI erase back through more words, rather than operating on themselves or something. Duh.

• SI is valid at the beginning of input, but only to deal with the fact computer parsing is often done line by line, and two lines can be from the same speaker (e.g. "mi broda co" followed later by "si do").
• SA+SI == nothing.

• SU+SI == nothing.
• SA+any word (except ZO)+SI == nothing (assuming that the SA is valid, i.e. that there is a word of the same selma'o as the word after SA to erase back to). For ZO you need two SI.

• • Not quite true; doesn't work for ZO or (probably) ZOI.
• ZO+any word+SI == ZO

• ZO+any word+SI+SI == nothing
• SI has no effect in a LOhU...LEhU even though ZO+LEhU does, so you can't do ZO+LEhU+SI+SI inside a LOhU...LEhU quote to get nothing.

• A SI immediately after the terminating LEhU of a LOhU...LEhU quote erases the LEhU, opening up the quote again. A string of SI in that position keeps erasing through the quote, possibly destroying it entirely (although SA+LOhU+SI is normally a much better way of accomplishing this goal). As soon as a non-SI word interrupts the string of SI after the terminating LEhU, that word and all other words until the next unquoted LEhU are considered part of the quote again, and have no grammatical function.
• SA can destroy LOhU...LEhU quotes, of course. LOhU...LEhU+SA+LOhU, in particular, is exactly equivalent to just LOhU (hence, the quote is re-opened). SA cannot erase to any other word in a LOhU...LEhU quote (because they are not considered part of any selma'o) except for ZO if a ZO+LEhU quote is used inside the LOhU...LEhU quote (because the ZO is used grammatically in this case, and hence has a selma'o in practice).

• SI can back into a ZOI quote in the same manner as into a LOhU...LEhU quote, except that all of the quoted non-Lojban text (which is considered non-Lojban text even if it clearly is) is treated as one word. So:
  • ZOI+delimiter+text+delimiter+SI == ZOI+delimiter+text

• • ZOI+delimiter+text+delimiter+SI+SI == ZOI+delimiter
  • ZOI+delimiter+text+delimiter+SI+SI+SI == ZOI

• • ZOI+delimiter+text+delimiter+SI+SI+SI+SI == nothing
• As a result of the above, if you really want to destroy a whole ZOI quote, SA+ZOI+SI is strongly reccomended.

• ZOI+SI == nothing (i.e. if you haven't presented a delimiter yet, SI can still operate).
• ZOI + SA + ZOI + SI still == nothing.

Error Cases

The following cases are explicitely defined as bad, i.e. error cases.

• ZO + any word + BU
• ZOI+delimiter+text+delimiter + BU

• ZEI + ZEI
• BAhE + end of text

• start of text + BU

Non-Error Cases

Cases that are degenerate and strange, but not errors.

• BU + ZEI + BU
• BAhE + ZOI -- ZOI retains its usual meaning

• BAhE + ZO -- ZO retains its usual meaning
• DAhO (and friends) + NAI + ZEI + any word