Do not restore pc when returning from top most fiber frame.
Also add JANET_DEBUG config define for various debugging related
configurations. In fiber.c, when debug is enabled we reallocate the
entire stack everytime we push a frame to help uncover use after free
errors.
Before, these bindings we just ignored. However, it useful for
controlling janet_printf and janet_eprintf, for example. These can
be called from C code without being inside a call to janet_continue.
This makes these operatios use constant stack space rather
than linear stackspace given the size of the inputs. This is important
to prevent certain parser input from causing a stack overflow - in
general, we try to avoid unbounded recursion.
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.
These additions, along with the change that user signals 0-4 cannot
be resumed, allow delimited continuation semantics, while repsecting
existing forms like `defer`, `with`, `with-vars`, etc.
Required a few changes to APIs, namely janet_root_fiber()
to get topmost fiber that is active in the current scheduler.
This is distinct from janet_current_fiber(), which gets the bottom
most fiber in the fiber stack - it might have a parent, and so cannot
be reliably resumed.
This is the kind of situation that makes symmetric coroutines more
attractive.
This changes the implementation of the `next` function which
is now used to implement each. This let's us iterate over
more types, not just tables and structs.
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.
Also make integer to size_t casts explicit rather than relying on
int32_t * sizeof(x) = size_t. This is kind of a personal preference for
this problem.
Because we use an amalgated build, feature
test macros should be set in a single file that
is included before any other headers, and is placed
at the top of the amalgamated build.
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 makes the names of the opcodes match their implied functionality.
We also rename the C functions to match the opcodes and source level
functionality.
Rather than messing with janet_core_dictionary, we
instead cache the core enevironment, and pull out the
needed tables from there. This is more flexible, more correct, and
also exposes janet_resolve_core, which can be easily used from the C
API.
doc macro can take no arguments and print out
all bindings. Fix an issues with the vm skipping
over a breakpoint in some situations.
Add examples/debugger.janet for proof of concept
debugger.
The new RNG wraps up state for random number generation, so
one can have many rngs and even marshal and unmarshal them.
Adds math/rng, math/rng-uniform, and math/rng-int.
Also introduce `in` and change semantics for
indexing out of range. This commit enforces stricter
invariants on keys when indexing via a function call
on the data structure, or the new `in` function.
The `get` function is now more lax about keys, and will
not throw an error when a bad key is used for a data structure, instead
returning the default value.
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.
This allows better stacktraces when manually intercepting
signals to clean up resources. Also allows functionality
from Common Lisp's unwind-protect, such as calling cleanup code
while unwindinding the stack, restarting on certain signals, and
just in general having more control over signal and signal propagation.
Also fix a bug encountered while implementing with-resource in the
compiler. Desturcturing arguments that were not the last argument
would often result in bad code generation, as slots used to destructure
the earlier arguments would invalidate the later parameters. This is
fixed by allocating all named parameters before doing any destructuring.
janet_vm_return_reg should only be set when janet_continue
is called. Otherwise, a panic may dump it's error message in
the wrong place, resulting in undefined behavior (often showing
the last return value or worse, segfaulting).
A consistent style should help with contributors and
readability. We use astyle as the formatter as can make a pretty
good approximation of the current style and my preferred style.
Astyle can be found at http://astyle.sourceforge.net/astyle.html
to make janet function calls easier and faster from C (still
needs an object pool for fibers, though). Fix bug in scan-number
and add many more peg tests.
Error handling is implemented with setjmp/longjmp so code
can be more concise. This required a very large but straight forward refactor for all
of the libraries.
Replace the oparg macro with 5 named virtual registers, combine
pc++ with vm_next() macro to be more terse, and move setup and
teardown logic of janet_continue into a separate function.
These changes are preparation for using setjmp/longjmp to do
error handling in the VM. Introducing longjmp for error handling in
the VM would allow it to be used in the C API, which could result in
simpler, more compact code.
remove some complexity and unexpected behavior around numbers in
general as all numbers are the same number type, IEEE 754 double
precision numbers. Also update examples and tests, some of which were
out of date.
Some more testing may be needed for new changes to numbers.
