How to loopback in pinescript to find a pattern in historical candle and get their bar index?

Question

I have a requirement to detect candlestick patterns in historical candles on each live candlestick bar formation and fetch their bar index.

For example, Suppose In Live market trading, I want to know if any candle of size 10 points is present in today's session historical candles.

I tried using for loop to backtrack but cant make it work as I am very new to pinescript.

Thanks in advance.

Answer 1

No need for a loop. Your script will be executed on each bar. So, you can keep track of that while new bars form. You can have a var array for the bar indeces. That way, its value won't be lost during the next iterations.

var idx_arr = array.new_int()

if is_new_session        // First bar of the new session
    array.clear(idx_arr) // Clear the array so the previous session values are gone
if (is_in_session)       // Only update your array when you are in a session
    if (your condition)  // Check for your condition
        array.push(idx_arr. bar_index)  // Push the bar index to your array whenever your condition is satisfied