Re: [Csnd-dev] [EXTERNAL] Re: [Csnd-dev] convert string to variable name

it seems serendipitous to talk about ref types since Steven put a comment in this closed issue:

https://github.com/csound/csound/issues/1661#issuecomment-3169348066

which seems to be in the direction I'd like to see. However someone will need to go and implement it.

We could open an issue on this but OTOH I hate to see issues opened that are never dealt with and ten years later they're still there.

So I don't really know what to do.

Prof. Victor Lazzarini
Maynooth University
Ireland

On 10 Aug 2025, at 14:28, Eduardo Moguillansky <[email protected]> wrote:


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evalstr works at the instr0 level and can only return scalar values.

Using ref/deref it can be done (see example below), but needs an external plugin. Maybe we could add these opcodes to csound itself?


instr 1

arr_1:i[] = [1,2,3]

arr_2:i[] = [4,5,6,7]

iregistry = dict_new("str:float", "arr1", ref(arr_1), "arr2", ref(arr_2))

if eventtime() > 0.05 then

; modifying the original array modifies the reference

arr_1[0] = 10

endif

; switch between the two at each cycle

Skey = sprintfk("arr%d", eventcycles() % 2 + 1)

karr[] = deref(dict_get:k(iregistry, Skey))

println "Skey: %s", Skey

printarray karr

endin


schedule 1, 0, 0.1


On Sun, Aug 10, 2025 at 11:20 AM joachim heintz <[email protected]<mailto:[email protected]>> wrote:
is it possible to convert a string to a variable name in csound 7?
use case:

// having two string variable names
arr_1:i[] = [1,2,3]
arr_2:i[] = [4,5,6]
// s will be either "arr_1" or "arr_2"
s:S = sprintf("arr_%d",int(random:i(1,2.9999)))
// the (not existing) opcode str2var would convert to the variable name
myvar = str2var(s)
// so now i can use myvar
print(myvar[0])

or something like python's eval() in csound?

(i tried the existing opcode evalstr but could not get to what i need.)

thanks -
        joachim