Is It Renoise Error Or Syntax Rule That I Am Missing?

[Laffik]

Jonas found bug in my tool - Progressor.

There are lines:

  
renoise.song().patterns[pattern].tracks[trackindex+1].lines[line].note_columns[1].delay_value=renoise.song().patterns[pattern].tracks[trackindex].lines[line].note_columns[1].delay_value   
 renoise.song().patterns[pattern].tracks[trackindex+1].lines[line].note_columns[2].delay_value=renoise.song().patterns[pattern].tracks[trackindex].lines[line].note_columns[1].delay_value   
 renoise.song().patterns[pattern].tracks[trackindex+1].lines[line].note_columns[3].delay_value=renoise.song().patterns[pattern].tracks[trackindex].lines[line].note_columns[1].delay_value  
  

It causes error

‘C:\Users\plugexpert\AppData\Roaming\Renoise\V2.7.2\Scripts\Tools\com.Laffik.Progressor.xrnx\main.lua’ failed in one of its notifiers.

Please contact the author (Laffik) for assistance…

std::logic_error: ‘trying to access a no longer available pattern_line note column.’
stack traceback:
[C]: ?
[C]: in function ‘__index’
[string “do…”]:12: in function <[string “do…”]:11>
main.lua:4641: in function ‘attachchords’
main.lua:4939: in function main.lua:4937

occuring when matching progression for three column track and cursor standing in first column. Normally Progressor should apply progression for first column.

I 've found a solution. Problem vanishes when changing listed lines to this:

  
 aa= renoise.song().patterns[pattern].tracks[trackindex].lines[line].note_columns[1].delay_value   
 renoise.song().patterns[pattern].tracks[trackindex+1].lines[line].note_columns[1].delay_value=aa   
 renoise.song().patterns[pattern].tracks[trackindex+1].lines[line].note_columns[2].delay_value=aa   
 renoise.song().patterns[pattern].tracks[trackindex+1].lines[line].note_columns[3].delay_value=aa  
  

I think both formulas are correct and only the second one is preffered. I can not find any explanation. Is this Renoise error or syntax rule that I am missing.
This lines can be found in Progressor_v082.xrnx archive in file main.lua in line 4640.

2552 Progressor_v082.xrnx

[taktik]

See [Fixed 2.8] Trying To Access A No Longer Available Pattern_Line Note C please

Locals are helping either way to make the thing a bit more readable (IMHO):

  
local pattern = renoise.song().patterns[pattern]  
  
local src_line = pattern.tracks[trackindex].lines[line]  
local dest_line = pattern.tracks[trackindex + 1].lines[line]  
  
local delay_value = src_line.note_columns[1].delay_value  
  
dest_line.note_columns[1].delay_value = delay_value  
dest_line.note_columns[2].delay_value = delay_value  
dest_line.note_columns[3].delay_value = delay_value