From 651fda1467ffb60e79954e7ba14b969c07c176df Mon Sep 17 00:00:00 2001
From: Manos Pitsidianakis <el13635@mail.ntua.gr>
Date: Thu, 12 Dec 2019 11:01:13 +0200
Subject: [PATCH] text_processing: use grapheme length in Truncate

---
 text_processing/src/lib.rs | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/text_processing/src/lib.rs b/text_processing/src/lib.rs
index 0e9002880..799fa85b0 100644
--- a/text_processing/src/lib.rs
+++ b/text_processing/src/lib.rs
@@ -14,10 +14,18 @@ pub trait Truncate {
 
 impl Truncate for &mut String {
     fn truncate_at_boundary(self, mut new_len: usize) {
-        while new_len > 0 && !self.is_char_boundary(new_len) {
-            new_len -= 1;
+        if new_len >= self.len() {
+            return;
+        }
+
+        extern crate unicode_segmentation;
+        use unicode_segmentation::UnicodeSegmentation;
+        if let Some((last, _)) = UnicodeSegmentation::grapheme_indices(self.as_str(), true)
+            .take(new_len)
+            .last()
+        {
+            String::truncate(self, last);
         }
-        String::truncate(self, new_len);
     }
 }