Data commit

Task/Tokenize-a-string-with-escaping/F-Sharp/tokenize-a-string-with-escaping.fs

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+open System
+open System.Text.RegularExpressions
+
+(*
+    .NET regexes have unlimited look-behind, so we can look for separators
+    which are preceeded by an even number of (or no) escape characters
+*)
+let split esc sep s =
+    Regex.Split (
+        s,
+        String.Format("(?<=(?:\b|[^{0}])(?:{0}{0})*){1}", Regex.Escape(esc), Regex.Escape(sep))
+        )
+
+let unescape esc s =
+    Regex.Replace(
+        s,
+        Regex.Escape(esc) + "(.)",
+        "$1"
+        )
+
+[<EntryPoint>]
+let main argv =
+    let (esc, sep) = ("^", "|")
+    "one^|uno||three^^^^|four^^^|^cuatro|"
+    |> split esc sep
+    |> Seq.map (unescape esc)
+    |> Seq.iter (fun s -> printfn "'%s'" s)
+    0