Documentation: "inability to inspect local variables in a given call frame"

[fosskers]

I was reading through the manual and noticed this point in Section 1.1.2, Contemporary Common Lisp:

An incomplete implementation of interactive debugging mechanisms, namely a no-op version of STEP6, the inability to inspect local variables in a given call frame, and the inability to resume a halted computation at an arbitrarily selected call frame

In particular it states the inability to inspect local variables in a given call frame, and yet I am able to inspect local bindings in all the available stack frames while in the interactive debugger. Am I misunderstanding the original wording?

Cheers!

[alejandrozf]

Do you mean using Slime or the plain REPL? How are you doing it?

With Slime I can see arguments of the functions called but not for local variables, for example

For this function:

I got this when calling with (test2 7):

but with no way to get the value of the variable b

In the plain REPL I saw options for inspect the value but they are not working for local bindings.

I didn't tried with abcl-instrospect, maybe using it is possible to inspect all local bindings.

On the other hand, there is a contrib for a working stepper called abcl-stepper (I'm the author) which allows to get the values of local bindings among other features. Maybe the documentation needs to be updated in that paragraph to mention it.

[fosskers]

Now that I'm testing it in SBCL, I'm actually seeing the same thing; I can't manage to get access to b within the debugger.

However, the good news is that Sly Stickers do work, so if I really need access to an inner variable, I can use those.

I think the original issue can be closed. Thanks!

[alanruttenberg]

@fosskers Have you tried to look at frames of functions that are interpreted? With ABCL-introspect those should be visible.

[fosskers]

It was the same result for either interpreted or compiled functions, although I was just using what Sly provides by default. I didn't try out abcl-introspect.

[alanruttenberg]

Right, it won't work unless abcl-introspect is loaded. Also, I'm not familiar with sly. Slime has the debugger support for this.