Pine script: indicating all time high/low when it occurs

Question

I want to indicate the bar at which the absolute all time high/low occurs. This means that if the previous all time/high low is superseded by a new one, the old one(s) shouldn't be indicated. Using hints from here , I was able to come up with this:

//@version=5

// initialization 
indicator(title="test", shorttitle="test", overlay=true)

// functions
allTimetHi(source) =>
    var atHi = source
    atHi := math.max(atHi, source)

allTimetLo(source) =>
    var atLo = source
    atLo := math.min(atLo, source)

plotchar(high == allTimetHi(high), title = "title", char = "*", location = location.abovebar, size = size.normal, color = color.lime)
plotchar(low == allTimetLo(low), title = "title", char = "*", location = location.belowbar, size = size.normal, color = color.red)

However, as can been seen from the image below, every local all time high/low is indicated:

Is there a way to achieve the effect that I want?

Answer 1

I would just use a label on each new high/low, and delete previous label :

//@version=5

indicator(title="test", shorttitle="test", overlay=true)

var float allTimetHi = 0
var float allTimetLo = 9999999999999999

allTimetHi := math.max(allTimetHi, high)
allTimetLo := math.min(allTimetLo, low)

if high == allTimetHi
    highLabel = label.new(bar_index, high, text="Highest High!", style=label.style_label_down, color=color.green)
    label.delete(highLabel[1])
    
if low == allTimetLo
    lowLabel = label.new(bar_index, low, text="Lowest Low!", style=label.style_label_up, color=color.red)
    label.delete(lowLabel[1])