Breaking a calculation into named steps makes the data flow easier to inspect and replay.

Program

Play the script to change the discount and watch each intermediate value stay visible.

intermediate_steps.R
discount <- 
price <- 80
tax <- 8
subtotal <- price - discount
total <- subtotal + tax
label <- paste("total", total, sep = ":")
cat(label, "\n", sep = "")
discount <- 
price <- 80
tax <- 8
subtotal <- price - discount
total <- subtotal + tax
label <- paste("total", total, sep = ":")
cat(label, "\n", sep = "")
discount <- 
price <- 80
tax <- 8
subtotal <- price - discount
total <- subtotal + tax
label <- paste("total", total, sep = ":")
cat(label, "\n", sep = "")
named step `subtotal` explains the price after the discount.
small expression Each line performs one simple calculation.
traceable flow Replay can show the discount, subtotal, and total separately.