Dynamic Array Reference

[barnjamin]

Problem

I'd like to be able to reference the elements of the Txn.application_args array dynamically using the looping construct with ScratchVars. Currently this is not supported but I see support is available in the Gtxn array.

example of what I'd like to do:

def set_properties(acct, args, start):
    idx = ScratchVar()

    init = idx.store(Int(start))
    cond = idx.load()<args.length()
    step = idx.store(idx.load() + Int(2))

    return Seq([
        For(init, cond, step).Do(
            App.localPut(acct, args[idx.load()], args[idx.load() + Int(1)])
        ),
        Int(1)
    ])

This may be supported in some way but I can't seem to find it.

Solution

Accept the Union[int,Expr] in the Txn array items __getitem__ call

[barnjamin]

algorand/go-algorand#2847 this may be a prerequisite?

[jasonpaulos]

This will be added for TEAL 5. We will also support dynamically getting arguments with Arg for LogicSigs.