Lazy verification makes it easier to not leave funcenvs
in an invalid state, as well as be more precise with the validation.
We needed to verify the FuncEnvs actually pointed to a stack frame if
they were of the "on-stack" variant. There was some minor checking
before, but it was not enough to prevent func envs from pointing to
memory that was off of the fiber stack, overlapping stack frames, etc.
Using a bitset to indicate which stack values are upvalues, we
can more accurately track when a reference to a stack value
persists after the stack frame exits.
User friendly delimited continuations. While this was doable with
signals before, this does not require C and will play nicely with
existing error handling, defers, and with statements.
While C functions are not re-entrant, signaling from a C function
can be used to implement async returns. When resuming a fiber that
signalled from within a C function, the fiber is started after the
instruction that emitted the signal. The resume argument is used
as the return result from the c function.
This unifies equality and comparison checking. Before, we had
separate functions and vm opcodes for comparing general values vs.
for comparing numbers, where the numberic functions were polymorphic and
had special cases for handling NaNs. By unfiying them, abstract types
can now better integrate with other number types and behave as keys.
For now, the old functions are aliased but will eventually be removed.
This adds several common patterns, which are defined in
boot.janet. This essentially gives more primitive patterns
to work with out of the box.
Fix build when JANET_REDUCED_OS is defined.
True top level unquote currently requires basically double compilation
as it currently stands. Also, implementing such double compilation
looses all source mapping information. This is a compromise
implementation that makes it clear that this works differently than
a true top-level unquote.
