[antlr-interest] ^ and ^^ tree operators (was: ANTLR 3 dev status?)
John D. Mitchell
johnm-antlr at non.net
Fri Mar 18 10:58:41 PST 2005
>>>>> "Sebastian" == Sebastian Kaliszewski <sk at z.pl> writes:
> Oh, one idea WRT ^ & ^^ 'operators' for tree creation in Parser. Those
> are nice but break compatibility with 2.x -- so maybe use good old ^
> instead od new proposed ^^ and ` to mean what ^ is proposed to mean in
> 3.0 (` is the reverse single quote, i.e that sign sharing the key with ~
> on most keyboards). Like ^ is half of ^^ then ` might be considered half
> of ^. Just an idea...
Using backtick for that? Eeeww... Hard to read, non-mnemonic (i.e., the ^
looks like a tree (to all use sick CS types :-)).
Remember that Antlr v3 is truly a new generation of Antlr/PCCTS. The idea
certainly isn't to gratuitously change things but after a fair bit of
analysis, thought, and argument (:-), adding ^^ as the rule root and
changing ^ to mean the local root really does seem to be justified is a
good step for the better.
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