Cyclomatic Complexity of R Code

Cyclomatic complexity is a software metric (measurement), used to indicate the complexity of a program. It is a quantitative measure of the number of linearly independent paths through a program's source code. It was developed by Thomas J. McCabe, Sr. in 1976.

cyclocomp

Cyclomatic Complexity of R Code

Cyclomatic complexity is a software metric (measurement), used to indicate the complexity of a program. It is a quantitative measure of the number of linearly independent paths through a program’s source code. It was developed by Thomas J. McCabe, Sr. in 1976.

Installation

devtools::install_github("Gaborcsardi/cyclocomp")

Usage

library(cyclocomp)

cyclocomp takes quoted R expressions or function objects, and returns a single integer, the cyclomatic complexity of the expression or function.

cyclocomp(quote( if (condition) "foo" else "bar" ))

#> [1] 2

cyclocomp(quote( while (condition) { loop } ))

#> [1] 3

cyclocomp(
  function(arg) { calulate(this); and(that) }
)

#> [1] 1

cyclocomp(ls)

#> [1] 10

cyclocomp(cyclocomp)

#> [1] 1

Some more examples for the R control structures. A simple if first:

cyclocomp(quote({
  if (condition) this
}))

#> [1] 2

An if with an else branch:

cyclocomp(quote({
  if (condition) this else that
}))

#> [1] 2

Loops:

cyclocomp(quote({
  for (var in seq) expr
}))

#> [1] 3

cyclocomp(quote({
  while (cond) expr
}))

#> [1] 3

cyclocomp(quote({
  repeat expr
}))

#> [1] 2

break and next statements add to the complexity:

cyclocomp(quote({
  for (var in seq) {
    this
    break
    that
  }
}))

#> [1] 4

cyclocomp(quote({
  for (var in seq) {
    this
    next
    that
  }
}))

#> [1] 4

Multiple (explicit or implicit) return calls also add to the complexity:

f <- function(arg) {
  if (arg) {
    return("this")
  } else {
    return("that")
  }
  "Otherwise return me"
}
cyclocomp(f)

#> [1] 4

License

MIT © Mango Solutions; Posit Software, PBC