Like any trailing stop when price is higher than the trailing stop this imply a buy signals, when price is lower than the trailing stop this imply a sell signal. It is possible to use decimals instead of integers for length as shown here :
length = 14.7
The indicator tend to react faster to price movements when a trend has been really long, this methodology is similar to the one used by the parabolic sar.
Downsides
Lack of robustness with the length parameter, the behaviour of the trailing stop can be hard to predict. There is a real need for control.
Conclusion
The indicator can be adaptive, even if it already is in a certain way, by changing the alpha variable at the start considering that 0 < alpha < 1. Its not recommended to use it right now except for testing/coding purpose.
It is clear that i'm not enthusiast when it come to this script, there is a real lack of accuracy, i still hope it can be of use.