add to_string function

.gitignore

@@ -0,0 +1,3 @@
+proj
+proj.du
+proj.ud

rope.sml

@@ -13,6 +13,7 @@ exception Size
 exception Ins
 exception Substring
 exception Delete
+exception To_string
 
 fun size rope = 
    case rope of
@@ -374,3 +375,24 @@ fun delete start length rope =
   in
     t
   end
+
+fun to_str acc rope =
+  case rope of
+    N0 str =>
+      (str::acc)
+  | N1 t => 
+      to_str acc t
+  | N2 (l, _, _, r) =>
+      let
+        val acc = to_str acc r
+      in
+        to_str acc l
+      end
+  | _ => raise To_string
+
+fun to_string rope =
+  let
+    val lst = to_str [] rope
+  in
+    String.concat lst
+  end

utils.sml

@@ -3,13 +3,13 @@ fun time_func title f =
     val title = String.concat ["Starting " , title , "..."]
     val _ = (print title)
     val start_time = Time.now()
-    val start_time = Time.toMilliseconds start_time
+    val start_time = Time.toNanoseconds start_time
     val x = f()
     val end_time = Time.now()
-    val end_time = Time.toMilliseconds end_time
+    val end_time = Time.toNanoseconds end_time
     val time_diff = end_time - start_time 
     val time_diff = LargeInt.toString time_diff
-    val time_took = String.concat ["took", time_diff, " ms\n"]
+    val time_took = String.concat ["took ", time_diff, " nanoseconds\n"]
     val _ = (print time_took)
   in
     x
@@ -19,9 +19,15 @@ fun run_txns arr =
   Vector.foldl 
     (fn ((pos, del_num, ins_str), rope) =>
       let
-        val rope = if del_num > 0 then delete pos del_num rope else rope
+        val rope = 
+          if del_num > 0 
+          then delete pos del_num rope 
+          else rope
         val str_size = String.size ins_str
-        val rope = if str_size > 0 then insert pos ins_str rope else rope
+        val rope = 
+          if str_size > 0 
+          then insert pos ins_str rope 
+          else rope
       in
         rope
       end) 
@@ -34,12 +40,27 @@ fun run_txns_time title arr =
     time_func title f
   end
 
+fun run_to_string rope =
+  to_string rope
+
+fun run_to_string_time title rope =
+  let
+    val f = (fn () => run_to_string rope)
+  in
+    time_func title f
+  end
+
 val _ =
   let
-    val _ = run_txns_time "svelte" svelte_arr
+    val svelte = run_txns_time "svelte" svelte_arr
-    val _ = run_txns_time "rust" rust_arr
+    val rust = run_txns_time "rust" rust_arr
-    val _ = run_txns_time "seph" seph_arr
+    val seph = run_txns_time "seph" seph_arr
-    val _ = run_txns_time "automerge" automerge_arr
+    val automerge = run_txns_time "automerge" automerge_arr
+
+    val _ = run_to_string_time "svelte to_string" svelte
+    val _ = run_to_string_time "rust to_string" rust
+    val _ = run_to_string_time "seph to_string" seph
+    val _ = run_to_string_time "automerge to_string" automerge
   in
     ()
   end