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.
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.
This should help when redefining certain forms. Will also
not do functional arity checking against nil forms, as that
is the default value when a def doesn't evaluate.
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.
These functions interact with Janet's dynamically scoped
IO functions in a manner that is more useful the file/flush.
We can still redirect to a buffer without changing our code.
This way we can support fewer build configurations. Also, remove
all undefined behavior due to use of memcpy with NULL pointers. GCC
was exploiting this to remove NULL checks in some builds.
Also add a few ctrl sequences from readline, and
ignore unknown ctrl sequences.
Address #264
Adds Ctrl-n, Ctrl-p, and Ctrl-w
Ignores unknown ctrl sequences
No alt-* sequences yet.
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.
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.
