It should be possible to set specific paths in Remap variables

[StephenWakely]

It would be useful to be able to modify paths within variables, so array indexes and subfields of the variable. Currently Remap just errors if this is attempted.

From discord

It would be useful to do this:

       if length(message_lines) > 1 {
          message_lines[0] = ""
          .log.extra = compact(message_lines, string: true)
        }

But currently we get this error:

error: path-based variable assignment
     ┌─ :65:23
     │
  65 │           message_lines[0] = ""
     │           ------------^^^^ assignment to variable path currently unsupported
     │           │
     │           assign to "message_lines" instead
     │
     = see language documentation at: https://vector.dev/docs/reference/vrl/

The only workaround currently is to temporarily move the variable to a path (which would not work for metric events):

.temp = message_lines
.temp[0] = ""
message_lines = .temp
del(.temp)