///|
/// `Cmd` represents an SVG command along with its parameters.
struct Cmd {
  c : String
  p : Params
} derive(Show, Eq)

///|
let split_re : @regexp.RegExp = @regexp.compile?("^([MLCQZ])([0-9\\.\\-, ]*)").unwrap()

///|
/// `split_path` splits an SVG path into an array of individual commands.
fn split_path(d : String) -> Array[Cmd]!FontError {
  let mut d = d
  let cmds = []
  while d.length() > 0 {
    let match_result = split_re.matches(d)
    match match_result.captures() {
      [_, c, p] => {
        d = d.substring(start=c.length() + p.length())
        let p = parse_params!(p)
        cmds.push({ c, p })
      }
      _ => raise FontError("split_path: unable to split SVG path \{d}")
    }
  }
  cmds
}

///|
test "split_path" {
  let d = "M507 24L48 24L48 530L395 530L395 625L48 625L48 723L507 723L507 24ZM395 269L395 433L138 433L138 269L395 269Z"
  let got = split_path!(d)
  let want = [
    { c: "M", p: Params([507.0, 24.0]) },
    { c: "L", p: Params([48.0, 24.0]) },
    { c: "L", p: Params([48.0, 530.0]) },
    { c: "L", p: Params([395.0, 530.0]) },
    { c: "L", p: Params([395.0, 625.0]) },
    { c: "L", p: Params([48.0, 625.0]) },
    { c: "L", p: Params([48.0, 723.0]) },
    { c: "L", p: Params([507.0, 723.0]) },
    { c: "L", p: Params([507.0, 24.0]) },
    { c: "Z", p: Params([]) },
    { c: "M", p: Params([395.0, 269.0]) },
    { c: "L", p: Params([395.0, 433.0]) },
    { c: "L", p: Params([138.0, 433.0]) },
    { c: "L", p: Params([138.0, 269.0]) },
    { c: "L", p: Params([395.0, 269.0]) },
    { c: "Z", p: Params([]) },
  ]
  assert_eq!(got, want)
}