all tasks

Task/Tokenize-a-string/OCaml/tokenize-a-string-1.ocaml

@@ -0,0 +1,7 @@
+let rec split_char sep str =
+  try
+    let i = String.index str sep in
+    String.sub str 0 i ::
+      split_char sep (String.sub str (i+1) (String.length str - i - 1))
+  with Not_found ->
+    [str]

Task/Tokenize-a-string/OCaml/tokenize-a-string-2.ocaml

@@ -0,0 +1,18 @@
+(* [try .. with] structures break tail-recursion,
+   so we externalise it in a sub-function *)
+let string_index str c =
+  try Some(String.index str c)
+  with Not_found -> None
+
+let split_char sep str =
+  let rec aux acc str =
+    match string_index str sep with
+    | Some i ->
+        let this = String.sub str 0 i
+        and next = String.sub str (i+1) (String.length str - i - 1) in
+        aux (this::acc) next
+    | None ->
+        List.rev(str::acc)
+  in
+  aux [] str
+;;

Task/Tokenize-a-string/OCaml/tokenize-a-string-3.ocaml

@@ -0,0 +1,14 @@
+let split_char sep str =
+  let string_index_from i =
+    try Some (String.index_from str i sep)
+    with Not_found -> None
+  in
+  let rec aux i acc = match string_index_from i with
+    | Some i' ->
+        let w = String.sub str i (i' - i) in
+        aux (succ i') (w::acc)
+    | None ->
+        let w = String.sub str i (String.length str - i) in
+        List.rev (w::acc)
+  in
+  aux 0 []

Task/Tokenize-a-string/OCaml/tokenize-a-string-4.ocaml

@@ -0,0 +1,3 @@
+#load "str.cma";;
+let split_str sep str =
+  Str.split (Str.regexp_string sep) str

Task/Tokenize-a-string/OCaml/tokenize-a-string-5.ocaml

@@ -0,0 +1 @@
+String.concat sep strings