[antlr-interest] Antlr v4 - C++ target

[Richard Gildea]

Hi,

These are mainly questions for Terrence/Sam Harwell (who I believe will be
writing the C++ target):

1) Is there even a vague estimate of when a likely C++ target is likely to
be available for v4 (even an alpha/beta version)? Is it likely to be on the
scale of e.g. 2-3 month, 4-6 months, 6 months-1 year, 1 year+?

2) Is the C++ target expected to have a much lower memory footprint than
the current v3.4 C target?

After recently realising that the v3.4 C target has a largish memory
footprint (see my recent emails to the list), there has been some pressure
among some of my co-developers to move to a handwritten parser over ANTLR
(especially from those who were suspicious of using ANTLR from the start)
in order to reduce the memory usage. Our parser is required to read files
as large as 0.5 Gb, hence the pressure to keep memory usage as low as
possible.

It sounds like v4 will likely be a big improvement over v3.4, and I think
knowing the answers to the above questions could influence whether or not
we move away from ANTLR with our parser.

Cheers,

Richard