Use the value of a variable in a string

[rondnelson99]

I'm back, and once again I'm trying to figure out what WLA's best equivalent is to a feature of RGBDS. My project sprinkles level data throughout the ROM in a very unconventional way, and I have this loop that is supposed to generate it:

.rept NUM_ROWS index ROW
    .org ROW << 8
    .section "level_row_{ROW}" FORCE
        .rept NUM_COLS index COL
            .arraydb level_vert COL+ROW*NUM_COLS
            .arraydb level_horiz COL+ROW*NUM_COLS
        .endr
    .ends
.endr

The important part here is that the data is spread throughout several sections that are generated in the loop. I understand that the sections need to have unique names, so my goal was to include the row number in the name. With RGBDS, I could use symbol interpolation to accomplish this. How would I do this in WLA? I understand that \@ is the intended way to make things unique in REPEAT blocks, but "level_row_@" isn't valid either.
Thanks,
Ron

[vhelin]

\@ works only in .MACRO, but you could do something like this:

        .define NUM_ROWS 8
        .define NUM_COLS 8

        .macro CreateSection ARGS ROWm
          .section "level_row_\1" FORCE
          .rept NUM_COLS index COL
            .dw COL+ROWm*NUM_COLS
            .dw COL+ROWm*NUM_COLS
          .endr
        .endm

        .rept NUM_ROWS index ROW
          .org ROW << 8
          CreateSection ROW
          .ends
        .endr

[rondnelson99]

Interesting, thanks. So basically you're saying that \@, \1, etc are expanded when used in strings, but all other variables are not. Is that correct?

BTW, what is the term that WLA uses for its build-time variables? I have seen other assemblers that call them "symbols" or "labels" (even when they do not reference a location in the ROM). What does WLA call them?

[vhelin]

There is no expansion for defines, only .MACRO arguments. You can always use a define as a .MACRO argument... This is where WLA-DX could be better, perhaps in the future I'll add support for global variable expansion in strings, if no-one else does that... Making a function for that, like defined() or asc(), might be the way to go?

Build-time variables? They are either .MACRO arguments or definitions, I guess?

[rondnelson99]

Ok, thanks! I suppose defines or definitions is the word I was looking for. I agree that global variable expansion is a useful feature that WLA would benefit from. However, the macro workaround works perfectly fine.

[vhelin]

If you now grab the latest sources, you can do a substitution as follows:

label_{COUNTER}:
.db { "COUNTER={COUNTER}" }