This will prevent these functions from being run
with empty strings, which usually produces useless
output, as the internal string search algorithm will
never "find" empty strings. This is by design, as it is
not always obvious which empty strings should be found in
the search text.
This should be friendlier to most users. It does, however, mean
we lose range information. However, range information could be
recovered by re-parsing, as janet's grammar is simple enough to do this.
Also adds the janet_lengthv API call. This is
needed because janet_length returns a 32 bit integer, where
as lengthv lets us return larger values (useful for typed arrays).
janet_mcall is an api function that should make it easier to call
a janet method from C code. It shares a similar signature with
janet_call.
Remove the multiple caching tables we were using
and use the grammar table for caching. This works
well because we can use raw_get for checking the local cache, and normal
get fro checking the global cache.
A keyword reference only counts as visited if we have
it as cached in the memoized->table, and we know it was
originally referenced from the same grammar table. If these
two conditions are true, then compilation must work correctly.
Also add janet_table_get_ex.
(backmatch [tag?]) is similar to a back reference in regular expressions
(NOT to backwards capture in a peg). It only matches a pattern if
it exactly matches the text of the last capture. It does not consume
or push any captures to the capture stack.
We normally only track memory allocated with janet_gcalloc, but
if only a few very large normal memory blocks are allocated, the GC
will never run. Se simply need to increment a count when we allocate
memory so that the next time we enter the VM, we will be able to
run a collection if needed.
