I’m a beginner in pine coding not in “regular coding” and I’m having a hard time understanding what information the highPrev variable holds from the bellow f_findDivs () function.
For reference, this is an extract of the VuManChu Cipher B + Divergences indicator which source can be found here : https://fr.tradingview.com/script/Msm4SjwI-VuManChu-Cipher-B-Divergences/

f_top_fractal(src) => src[4] < src[2] and src[3] < src[2] and src[2] > src[1] and  src[2] > src[0]
f_bot_fractal(src) => src[4] > src[2] and src[3] > src[2] and src[2] < src[1] and src[2] < src[0]
f_fractalize(src) => f_top_fractal(src) ? 1 : f_bot_fractal(src) ? -1 : 0

f_findDivs(src, topLimit, botLimit, useLimits) =>
    fractalTop = f_fractalize(src) > 0 ? src[2] : na
    fractalBot = f_fractalize(src) < 0 ? src[2] : na
    highPrev = valuewhen(fractalTop, src[2], 0)[2]
    […]

f_top_fractal and f_bot_fractal detect a fractal “shape” of data.

• Is fractalTop the same value on each iteration when valuewhen() uses it a the condition on previous values of the src[2] series ?
• valuewhen() returning a value, why applying the historical operator [2] on the result of the valueWhen() ? Which history is it ?
• The documentation does not tell about truthy and falsy values. Is any integer/float considered as true when passed to the condition parameter of valuewhen()

NB: in the quoted code, I removed from the source the useLimits logic for the sake of focus

Thanks in advance for any answer or comment, this language is really brainf???????? me