Question

I am working with numbers a lot when editing a particular type of file, and it’s mostly tedious work. The file has a format like this:

damagebase = 8.834
    "abc_foo.odf" 3.77
    "def_bar.odf" 3.77
    "ghi_baz.odf" 3.77
    "jkl_blah.odf" 4.05
    ...

What would you recommend for writing a script that parses this and lets me programmatically change each number?

Language: i use C#, some F# (noob), and Lua. If you suggest regexes, could you provide specific ones as i am not familiar with them?

Answer 1

You can match runs of non-whitespace and punt to Double.Parse:

int multiplier = 3;

string input =
  "damagebase = 8.834\n" +
  "  \"abc.odf\" 3.77\n" +
  "  \"def.odf\" 3.77\n" +
  "  \"ghi.odf\" .77\n" +
  "  \"jkl.odf\" -4.05\n" +
  "  \"mno.odf\" 5\n";

Regex r = new Regex(@"^(\w+)\s*=\s*(\S+)" +
                    @"(?:\s+""([^""]+)""\s+(\S+))+",
                    RegexOptions.Compiled | RegexOptions.Multiline);

Match m = r.Match(input);
if (m.Success) {
  double header = Double.Parse(m.Groups[2].Value);
  Console.WriteLine("{0} = {1}", m.Groups[1].Value,
                                 header * multiplier);

  CaptureCollection files = m.Groups[3].Captures;
  CaptureCollection nums  = m.Groups[4].Captures;
  for (int i = 0; i < files.Count; i++) {
    double val = Double.Parse(nums[i].Value);
    Console.WriteLine(@"  ""{0}"" {1}", files[i].Value,
                                        val * multiplier);
  }
}
else
  Console.WriteLine("no match");

Running it gives

damagebase = 26.502
  "abc.odf" 11.31
  "def.odf" 11.31
  "ghi.odf" 2.31
  "jkl.odf" -12.15
  "mno.odf" 15