[antlr-interest] What do . (period) and Tokens mean in tree
grammars? Harald M. Müller harald_m_mueller at gmx.de Sat Dec 29
14:16:13 PST 2007 Sorry that I ask - but I did not find it on
the Wiki and not in the ANTLR book: What do . and Tokens mean in
tree grammars? AFAIK, . means "any complete subtree." - although
this seems not to work in some current builds, if I understood
some email of yesterday correctly? Question number two: Does a
single Token also match a complete tree with this token at the
root, or only a "childless tree" (i.e. the token as a tree node
alone)? Question number three: What sort of lookahead is used
over . ? For example, would the following work - assume here
that the subtrees can be arbitrarily large subconditions (as is
usual in expression trees): condition : ^(AND . ^(NOT .)) ->
...rewrite1... | ^(AND . .) -> ...rewrite2... The intention of
this is to rewrite an AND tree which has as second child a tree
with a NOT root to rewrite1; whereas all other trees are
supposed to be rewritt