Hi,
On Mon, 13 Dec 1999, Lars Skovlund wrote:
> > [Said()]
> > There is no mention of the '&' and '#' tokens (0xf1/0xf7). OTOH, I don't
> > recall # being used in any of the Said specs I saw...
> > How are they treated by SCI?
> Not at all (?!). It sounds strange, I know, but I have also found (in the
> undocumented second part of the code)
> testing for some storage codes which can never appear in said trees, at least in
> release versions. Perhaps they are the activation switch for an in-house said
> debugger or something.
Do you happen to know if SCI01 uses them?
> > > Each "lexeme" (well, most of them) is added to the tree for later use by the
> > > second phase of Said(). This is done by a process called "augmenting" the
> > > tree. The augmentation process joins a sub-expression with the main tree,
> > > adding two descriptive storage codes. The result of an augmentation is
> > > sketched below:
> > >
> > > (parent node in main tree)
> > > / \
> > > / \
> > > (not assigned) tree node
> > > / *1
> > > /
> > > tree node
> > > / \
> > > / \
> > > nodeval1 (beginning of subtree)
> > > / *2
> > > /
> > > nodeval2
> >
> > So it could also be interpreted as a singly linked list with one optional
> > value per node?
Hmm, let me re-iterate on that one (I suppose this was wrong there,
anyway).
Let's assume that the parser matches the expression
Mainexp ',' Expression
which is a valid Expression. It then proceeds to recurse on both
the matched Mainexp and the Expression (Let's call them M and E),
attaching the results to the augmentation branch of the original
Expression. Now the question is: Where are they attached?
The augmentation branch described above has two unused branches on its
tree nodes (marked with *1 and *2), however, only *2 is known to be
related to subtrees. So, would, in my example, M be linked to *1 and
E to *2, or the other way around- or would *2 point to an additional tree
node linking to M and E?
> > > The right branch of the subtree, of course, contains the subtree information.
> > > Below is a listing of the storage codes used for the augmentation in various
> > > places. The names Ia use correspond to the yacc representation above:
> > >
> > > Lexeme nodeval1 nodeval2 comments
> > >
> > > MainExp/Wordgroup 0x141 0x153 **
> >
> > Where's ** and where do they store word groups? :-)
> >
>
> Right :-). The word node part of a tree will look like this:
>
> -----
> / \
> 0x141 / \
> / \
> / \
> / \
> 0x153 0x7D1
Where 0x7d1 is the word group?
llap,
Christoph
