Remove almost all the uses of string concatenation when building error messages.

Since error messages are ultimately passed to Format, which has its own
buffers for concatenating strings, using concatenation for preparing error
messages just doubles the workload and increases memory pressure.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/pp.ml b/lib/pp.ml
index d672f06db..9667f7270 100644
--- a/lib/pp.ml
+++ b/lib/pp.ml
@@ -249,7 +249,7 @@ let escape_string s =
     else escape_at s (i-1) in
   escape_at s (String.length s - 1)
 
-let qstring s = str ("\""^escape_string s^"\"")
+let qstring s = str "\"" ++ str (escape_string s) ++ str "\""
 let qs = qstring
 let quote s = h 0 (str "\"" ++ s ++ str "\"")