Expand capabilities of the debug instruction

[Fumuran]

This PR expands the capabilities of the debug instruction by printing information about memory and procedure locals, namely:

• debug.mem prints out the entire contents of RAM.
• debug.mem.<n> prints out contents of memory at address n.
• debug.mem.<n>.<m> prints out the contents of memory starting at address n and ending at address m (both inclusive). m must be greater than n.
• debug.local prints out all locals of the currently executing procedure.
• debug.local.<n> prints out contents of the local at index n for the currently executing procedure.
• debug.local.<n>.<m> prints out contents of the local starting at index n and ending at index m (both inclusive). m must be greater than n.

TODO:

• Update docs and changelog

[bobbinth]

Thank you! Looks good! This is not a full review yet, but I wanted to leave a few comments and I think it will change things a bit.

Also, could you paste a couple of screen shots of how the results look like?

[Fumuran]

There is a problem with formatting the final print of the memory address and value (as you mentioned it here).

I didn't find the way to parametrize the output: in case we print in decimal we need to have something like println!("{address:<10}: ...") — so we want to add space for potentially long u32 value and move it to the left side of the output. I also added dots to make it look a little bit more pretty (println!("{address:.<10}: ...")), but it is not important now. In case we want to print address in hex we use something like println!("{address:#010x}: ...") — #x for hex form and 010 for making hex to be length 10 which is spaced with 0's. The problem is that I don't know how to use some kind of parameter which would specify the output appearance (.<10 in the first example and #010x in the second).

Without that parametrization the code which outputs the values would be almost identical except the parts mentioned above, so there will be a lot of copy-paste. For now I left only the decimal form for both global and local memory. I am not sure how these addresses would be used in debugging, so I don't now how crucial or convenient will be using hexes instead of decimals.

Now output looks like that:

[bobbinth]

Thank you! I left some more comments inline. Regarding formatting, I suggested how we can format addresses/indexes for mem vs. locals. Let me know if that doesn't work for some reason.

[Fumuran]

I thought that it's strange to restrict user to request the locals in any interval he wants (as we do it in memory), so I get rid of the check if the end of the interval is smaller than number of locals. Instead I added a check that the end of the interval is smaller than 2^16 (since it's forbidden to have more than 2^16 locals for each procedure). Using it I also implemented the "print whole local memory" variant without boolean flag, using 2^16 as an end of the interval in that case.

What do you think about this decision? Should I return everything as it was?

Now output looks like this:

[bobbinth]

Looks good! Thank you! I left a few more comments inline.

[bobbinth]

What do you think about this decision?

I think it looks good! Let's keep it as you have it.

[bobbinth]

Looks good! Thank you! I left a few nit comments inline. After these are addressed, we can merge.