www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - A string splitting from the right

If I have a string as "10,20,30" and I need to split it taking 
the part after the last comma and all before it, in Python I use 
rsplit with optional argument 1:

 s = "10,20,30"
 a, b = s.rsplit(",", 1)
 assert a, b == "10,20", "30"
The optional second argument tells Python when to stop splitting, and the "r" suffix of split means from the right:
 "10,20,30,40,50".rsplit(",", 2)
['10,20,30', '40', '50']
 "10,20,30,40,50".split(",", 2)
['10', '20', '30,40,50'] One awkward way to do the same thing in D+Phobos is: import std.algorithm: find; import std.range: retro; void main() { auto s = "10,20,30"; string a = s.retro.find(",").retro[0 .. $ - 1]; string b = s[a.length + 1 .. $]; assert (a == "10,20"); assert(b == "30"); } I don't see a rsplit or rSplit or rightSplit in std.string, but I see findSplitAfter and findSplitBefore in std.algorithm: s.findSplitAfter(",") ==> Tuple!(string, string)("10,", "20,30") s.findSplitBefore(",") ==> Tuple!(string, string)("10", ",20,30") If I use std.range.retro: s.retro.findSplitBefore(",") ==> Tuple!(Result, Result)(03, ,02,01) Also notice the lack of " inside the tuple, those aren't strings. And indeed this is not accepted: s.retro.findSplitBefore(",")[0].retro So do you think it's a good idea to add a rSplit(string,count=-1) (or rightSplit) to std.string or std.array (and maybe add a second argument to std.array.split), or I am missing something from Phobos? Bye and thank you, bearophile
Jun 04 2013