I think there's a flaw in the way that Pine Script evaluates boolean expressions, that can hugely affect performance.
See this example
//@version=4
study("PlayGround", overlay=true)
var int y = 0
f1() =>
label.new(bar_index, high)
true
if false and f1()
y := y + 1
plot(y, title="y")
The statement if false and f1() should not need to evaluate the outcome of function f1() in order to know that the result will always be false.
However - as demonstrated by the fact that labels are drawn on the chart - the function f1() is still executed on every bar.
So Pine Script seems to evaluate the entire expression before making a decision, which is unnecessary.
Don't know if this is by design, but I think this should be corrected.
Contextual info
I have a script that contains a huge number of consecutive if statements to check wether the current bar is on a certain date.
In an attempt to improve the performance, I added a boolean variable to be evaluated first on each if statement.
(an example can be seen in the f_prediction_daily() function in Plotting custom data - daily = ok, weekly = not ok)
But as my list of if statements grew larger I noticed a decrease in performance.
Therefore, I've created this little test and question.
Correct. The evaluation of boolean expressions does not currently short-circuit in Pine, so all elements in the expression are evaluated.