> When you envision 'even longer modifier trains', you are implicitly
requiring a stack of more than 4 words.

which can be avoided by (auto)parenthesizing outer modifier train, such that 
there's always at most 4 tokens. 


Do I understand the following expression to mean that modifier trains group 
left to right (somehow)?

 @ @ + - @

(@ @ +) - @


 @ @ + - @ /

((@ @ +) - @)/



/ @ @ + - @

|syntax error

| /@@ +-@


/ (@ @ + - @)

/((@ @ +) - @)


@ + @ - @

(@ + @) - @

shouldn't it group from the right?


On Sunday, September 26, 2021, 10:46:13 p.m. EDT, Henry Rich 
<[email protected]> wrote: 





Since the goal was to make the old documents still usable, changes would 
require strong arguments demonstrating their superiority.  You are 
pitting yourself against Ken Iverson: may the better man win.

I can assure you that whatever is in your 'templating system' had zero 
influence on the design and implementation of {{ }} .

When you envision 'even longer modifier trains', you are implicitly 
requiring a stack of more than 4 words.

Henry Rich

On 9/26/2021 10:34 PM, 'Pascal Jasmin' via Programming wrote:
> I've been working on an autoparenthesizing of modifier trains, with 
> interpretations that would seem much more useful than the "old stuff".  I 
> don't have a good interpretation for A V train, so I guess it could stay as 
> suggested.  The following are what I'd prefer, added after -> ( = means 
> equivalent)
>
>
> V0 V1 C2    conj    V0 V1 (u C2 v)  -> V0 (V1 C2) = V1 C2 V0
> A0 V1 V2    adv    (u A0) V1 V2
> C0 V1 V2    conj    (u C0 v) V1 V2 -> (C0 V1) V2 = A V2
> C0 V1 C2    conj    (u C0 v) V1 (u C2 v) -> u (C0 V1) (C2 v)
> A0 A1 V2    conj    (u A0) (v A1) V2 -> (u A1 A2) V2
> N0 C1 A2    adv    N0 C1 (u A2) -> u (N0 C1) A2
> N0 C1 C2    conj    N0 C1 (u C2 v) -> u (N0 C1) (C2 v) = ((N0 C1 u) C2 v) = 
> (v (u (N0 C1)) C2)  parentheses not needed.
> V0 C1 A2    adv    V0 C1 (u A2)  -> u (V0 C1) A2
> V0 C1 C2    conj    V0 C1 (u C2 v) -> same as N C C
> A0 C1 N2    adv    (u A0) C1 N2
> A0 C1 V2    adv    (u A0) C1 V2
> A0 C1 A2    conj    (u A0) C1 (v A2)  -> u A0 (C1 v) A2
> A0 C1 C2    conj    (u A0) C1 (u C2 v) -> ((u  (A0) (C1 v)) C2) = adverb
> C0 C1 N2    conj    (u C0 v) C1 N2 ->  v (u C0)(C1 N2) =  (u C0 v)(C1 N2)
> C0 C1 V2    conj    (u C0 v) C1 V2  -> same as above
> C0 C1 A2    conj    (u C0 v) C1 (v A2) -> ((u C0 v) C1) A2 = adverb
> C0 C1 C2    conj    (u C0 v) C1 (u C2 v) -> ((u C0 v) C1) C2 = conjunction A C
> A0 C1    adv    (u A0) C1 u (adverbial hook)  -> (u A0) C1 v
>
> The beauty of the suggested forms is that there is not much to remember, and 
> allows for parenthesless forms.
>
> V0 V1 C2 -> V0 (V1 C2) is just the only valid parenthesization of the left 
> expression.
>
> C0 vn C2... More modifiers -> (C0 vn) C2...M ie. when a nv term is between 2 
> conjunctions it binds to the left one.
>
> Whenever C vn appears, (C vn) is bound is the only special rule.  It binds 
> ahead of other modifiers to right.
>
> To permit even longer modifier trains, while keeping the 4 token stack:
>
> C0 C1 M2 M3 -> C0 C1 (M2 M3)
>
> Reusing parameters in multiple modifiers seems stranger than the still 
> strange inserting them seemingly arbitrarily within a modifier train. If 
> these are useful, they are best made into a purpose modifier rather than as 
> default parsing rules that will confuse.
>
> A cool enhancement would be multiple right bindings to modifier trains that 
> contain multiple conjunctions:
>
> (C0 C1 M) v -> (C0 v) C1 M ie. A conjunction modifier train binds v to the 
> leftmost (unbound) conjunction.
> ((C0 v) C1 M) v2 -> (C0 v) (C1 v2) M = (C0 C1 M) v v2
> u ((C0 v) C1 M) -> ((u C0 v) C1) M ie binding from left or right provides 
> options similar to "old stuff"
>
> templating system that may have formed basis for {{ }}, and allows for rich 
> custome modifier trains:  
> http://www.jsoftware.com/pipermail/programming/2020-September/056558.html
>
>
> On Sunday, September 26, 2021, 12:01:45 p.m. EDT, Henry Rich 
> <[email protected]> wrote:
>
>
>
>
>
> Nostalgic old-timers will be happy to see the return of Modifier Trains,
> such as (@/), which were in early J but were deleted long ago.  See
> https://code.jsoftware.com/wiki/Vocabulary/fork#invisiblemodifiers .
>
> These trains were one of Ken Iverson's elegant brilliancies.  Few used
> them, and they are not needed, because anything they do can also be done
> with explicit modifiers ({{ u @ v/ }} is equivalent to (@/)).  No one
> need rush out and look at them.
>
> We have brought them back because to do so was easier than updating all
> the old J literature that refers to the forms.  And because they're cool.
>
> Henry Rich
>


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