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

It’s possible to create a new variable but you need to recompile the code.
> On 10 Aug 2025, at 10:20, joachim heintz  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

yes perhaps it is something for later --- i think we should concentrate 
now on releasing csound 7 without somehow luxurious wishes like that ...


On 11/08/2025 23:50, Victor Lazzarini wrote:
> 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 
>>  wrote:
>>
>> 
>>
>>
>>   *Warning*
>>
>> This email originated from outside of Maynooth University's Mail 
>> System. Do not reply, click links or open attachments unless you 
>> recognise the sender and know the content is safe.
>>
>> 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 > > 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
>>