See [lix-project/lix#1156], but basically currently the `:st <n>`
debugger command doesn't allow any negative indices, and putting a plus
sign in front of the arg doesn't change anything; thus, we can exploit
that "design space" to allow users to move between different stack
frames easily, by simply prepending their arg with a +/- sign.
The actual behavior is little more nuanced when you account for errors:
as suggested by @pennae (thanks! :), when the user inputs an offset that
would result in an invalid frame index, the debugger instead clamps it
to the closest bound (i.e. 0 for negative offsets, $maxFrame for
positive ones) and just prints a warning.
Fixes#1156
[lix-project/lix#1156]: https://git.lix.systems/lix-project/lix/issues/1156
Change-Id: I02a0cdb6aaebbdb0515308880a3bf9c0d2fcd25e
It's 2026 and the command handler was entirely manual!
We introduce a basic command handler framework for the REPL that handles
all the previous (implicit) features reasonably well.
This also builds up the infrastructure for nicer features.
Most important feature is that now we can let external plugins adds
commands to the REPL.
There's slight REPL changes:
- errors for debugger commands are more explicit.
- short-hand have a long-hand version.
- help shows command sorted by std::map natural key sorting (based on aliases)
while keeping the special syntaxes for the REPL language at the top.
- sections were introduced for Flakes commands.
- :st was merged into one command with an optional argument marker.
Change-Id: Ibd24f994491bf5d45d4b218fd84c0944ae5050fd
Signed-off-by: Raito Bezarius <raito@lix.systems>
this also fixes a debugger bug where leaving the debugger does not clean
up old debugger state completely. in such cases the fake frame withFrame
created was left behind after the corresponding caller frame was unwound
Change-Id: I45adcd116276b03b2f87076518c9eae6fe844e06
checking whether a repl hook is set does not tell whether it's running,
which in turn means we will enter a debug repl even when not debugging.
this is not very useful when we have no debug frames to inspect at all,
as commonly happens when starting a new repl with --debugger specified.
Change-Id: I7065dc4ec29743bdd53ed99c29d6592e2ceea89c
blokyk