[safe-string] Use `String.init` to build string.

1 files changed, 21 insertions, 18 deletions

diff --git a/lib/unicode.ml b/lib/unicode.ml
index ced5e258c2..3ac4e8ca7c 100644
--- a/lib/unicode.ml
+++ b/lib/unicode.ml
@@ -125,26 +125,29 @@ let utf8_of_unicode n =
   if n < 128 then
     String.make 1 (Char.chr n)
   else if n < 2048 then
-    let s = String.make 2 (Char.chr (128 + n mod 64)) in
-    begin
-      s.[0] <- Char.chr (192 + n / 64);
-      s
-    end
+    String.init 2 (fun idx ->
+        match idx with
+        | 0 -> Char.chr (192 + n / 64)
+        | 1 -> Char.chr (128 + n mod 64)
+        | _ -> 'x'
+      )
   else if n < 65536 then
-    let s = String.make 3 (Char.chr (128 + n mod 64)) in
-    begin
-      s.[1] <- Char.chr (128 + (n / 64) mod 64);
-      s.[0] <- Char.chr (224 + n / 4096);
-      s
-    end
+    String.init 3 (fun idx ->
+        match idx with
+        | 0 -> Char.chr (224 + n / 4096)
+        | 1 -> Char.chr (128 + (n / 64) mod 64)
+        | 2 -> Char.chr (128 + n mod 64)
+        | _ -> 'x'
+      )
   else
-    let s = String.make 4 (Char.chr (128 + n mod 64)) in
-    begin
-      s.[2] <- Char.chr (128 + (n / 64) mod 64);
-      s.[1] <- Char.chr (128 + (n / 4096) mod 64);
-      s.[0] <- Char.chr (240 + n / 262144);
-      s
-    end
+    String.init 4 (fun idx ->
+        match idx with
+        | 0 -> Char.chr (240 + n / 262144)
+        | 1 -> Char.chr (128 + (n / 4096) mod 64)
+        | 2 -> Char.chr (128 + (n / 64) mod 64)
+        | 4 -> Char.chr (128 + n mod 64)
+        | _ -> 'x'
+      )
 
 (* If [s] is some UTF-8 encoded string
    and [i] is a position of some UTF-8 character within [s]