Hi, I stumbled upon a surprising behavior when using an active binding as a loop index variable in R 4.0.0. In contrast, the behavior observed in R 3.6.1 is in line with my expectations.
Consider the code below: makeActiveBinding("i", function(value) { if (missing(value)) { x } else { print("set") x <<- value } }, globalenv()) i <- 1 # output "set" print(i) # output [1] 1 # Surprising behavior starts here: for(i in 2:3) print(i) # output [1] "set" # NULL # NULL print(i) # output NULL print(x) # output NULL i <- 4 # output "set" print(i) # ouput [1] 4 print(x) # ouput [1] 4 Regards Thomas
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Description: Digitale Signatur von OpenPGP
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