Re: Stack-based syntax (was: affixes)

On Monday, February 21, 2005, at 08:12 , Jörg Rhiemeier wrote:

> Hallo!
>
> On Sun, 20 Feb 2005 19:09:57 +0000,
> Ray Brown <ray.brown@...> wrote:
>
>> On Saturday, February 19, 2005, at 11:01 , # 1 wrote:
[snip]
>> I am strongly of the opinion that if one is going to construct a truly
>> stack-based syntax one simply has to think in terms quite different from
>> traditional western 'parts of speech'.
>
> Maybe.  Fith still has nouns and verbs, though.  But at least,
> adjectives and adverbs are one and the same in Fith.  The difference
> is merely what is on top the stack, an NP or a clause.
Yes, I have now looked at Fith. I was writing in general terms about how I
perceived a stack-based syntax.

Fith does indeed have a part of speech called a 'modifier' which acts as
an adjective if the top of the stack is a NP or as an adverb if it is a VP.
  The modifier combines both lexical meaning and also acts as an operator.
I assume this must have some parallel in FORTH.

I am well acquainted with stacks and their various uses. Probably because
I associate 'stack-based syntax' or LIFO syntax with the evaluation of
'Reverse Polish' expressions, I would prefer operators and lexical items
to be kept distinct.

>
>>> Articles would also work that way to tell the definiteness of the noun
>>
>> _Many_ languages do not have articles. I believe in fact the majority do
>> not. So I think one needs to ask whether they would figure at all.
>
> Yep.  I think Fith has articles, though, which are indeed unary
> operators.
It does indeed & they are unary operators - but their use is optional,
which is not the case with unary oprators like NEG or NOT.

>>> Case marks would act that way with a single noun
>>
>> Surely not! Is not the whole point of case markings that they show how
>> the
>> noun/pronoun _relates_ to some other part of the sentence (usually the
>> verb). As I see it, the the case markings are binary operators.
>
> Yes.  Case markers in Fith are binary operators: they take the NP
> on top of the stack and the item (phrase or clause) below it, and
> knit them together.
Which is exactly what one expects. Although in the version of Fith I
downloaded, it says "Nouns are not marked for number, gender or case.." I
assume we're talking here of postpositions.

>>> And the intransitive verbs also because they only affect one noun
>>
>> I do not see how a lexical category like verb should act as an operator.
>> Isn't it something more like: singing, John, NOM = John is singing?
>
> It is a question of semantics.  In Fith, verbs are indeed operators.
> Intransitive verbs are unary operators, transitive verbs are binary
> operators.
You're right. Once again the Fith verb is combining both lexical meaning
and operator.

>  Perhaps more "part-of-speech" thinking involved here
> than there should be.
I agree entirely. My impression is that the Fithians, tho intelligent
marsupials, are not so very alien from us humans. IMO the language is too
dependent on western IE language structures. It is even necessary,
apparently, for the Fithians to use hand signals in conjunction with
speech to clarify parts of speech - "The exact part of speech is marked by
a hand signal..."

If I were asked to construct a language with stack-based syntax I would
keep lexical items strictly separate from operators. The lexical items
would be my 'literals' and the idea of 'part of speech' has no meaning in
that context.

>>> Other operators will simply link two arguments in different ways like
>>> conjonctions and other in more sophisticated ways like transitive verbs.
>>
>> I would see a transitive verb more like: (John NOM (loving ACC Jennifer)
>> )
>> which in postifix (stack-based) form would be: John, loving, Jennifer,
>> ACC,
>>   NOM.
>
> Yes, that's more elegant.  Keeping content words and operators nicely
> apart.
Yes, certainly more what I am used to.

>> [...]
>>
>>> On Sunday, February 20, 2005, at 03:56 , # 1 wrote:
>> [snip]
>>
>>> Isn't exactly as an SOV, postpositionnal, noun-adj language?
>>
>> IMO no - not exactly. Certainly such a language might be a good place to
>> start.
>
> A stack-based language is not only "not exactly" an "SOV,
> postpositional,
> noun-adj language", it is *not at all*.
I agree - I was indulging in typical British litotes, and I didn't want to
be too discouraging to Max. But you are right - it ain't a SOV at all.

> It lies wholly outside the
> range of human language structures.  A simple clause in a stack-based
> language may perhaps look like one in an SOV, postpositional, noun-adj
> language (as a simple clause in Fith indeed looks like), but that
> resemblance is merely superficial, because the clause is parsed in an
> utterly different way from *any* human language.
I agree entirely. Unfortunately IMO because Fith is described in terms of
the familiar Latinate 'parts of speech' one can get the impression that
the stack is merely another way of presenting a SOV human language. In
fact, as you say, a true stack-based language will be utterly different
from any human language. But it is not easy for us to think in alien terms
  :)

[snip]
>>>
>>> A sentence like:
>>>
>>> dog the big cat your small love = the big dog loves your small cat
>>
>> But this doesn't clearly separate lexical items and operators. This would
>> imply, for example, that 'love' is a combination of lexical item and
>> operator. IMO in a truly stack-based system, lexical items and operators
>> should be kept distincr.
>
> That would at least be more elegant.  However, in Fith, verbs are
> operators as well as lexical items, as in the example sentence above.
True - as I said, I wrote the remarks above before looking again at Fith.
To me Fith seems a bit of a compromise, but maybe this true of FORTH - I
don't know.

[snip]
>> IMO with a stack-based syntax, lexical items are literals and operators
>> make explicit how the literals relate to one another.
>
> Yes, that would be indeed much more elegant than Jeffrey's Fith.
Thanks  :)

Ray
===============================================
http://home.freeuk.com/ray.brown
ray.brown@freeuk.com
===============================================
Anything is possible in the fabulous Celtic twilight,
which is not so much a twilight of the gods
as of the reason."      [JRRT, "English and Welsh" ]

Replies