From 5e06941c63425ab10e08e4d533939c7309cfe6ce Mon Sep 17 00:00:00 2001
From: Laurenz <laurmaedje@gmail.com>
Date: Tue, 5 Oct 2021 17:57:30 +0200
Subject: [PATCH] Iterate over grapheme clusters instead of chars

---
 Cargo.toml             | 1 +
 src/eval/str.rs        | 6 ++++--
 tests/typ/code/for.typ | 6 +++---
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index c1841af9b..c7fa703c4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,6 +29,7 @@ rustybuzz = "0.4"
 serde = { version = "1", features = ["derive", "rc"] }
 ttf-parser = "0.12"
 unicode-bidi = "0.3.5"
+unicode-segmentation = "1.8"
 unicode-xid = "0.2"
 xi-unicode = "0.3"
 anyhow = { version = "1", optional = true }
diff --git a/src/eval/str.rs b/src/eval/str.rs
index 59e0887ae..800d17093 100644
--- a/src/eval/str.rs
+++ b/src/eval/str.rs
@@ -3,6 +3,8 @@ use std::convert::TryFrom;
 use std::fmt::{self, Debug, Formatter, Write};
 use std::ops::{Add, AddAssign, Deref};
 
+use unicode_segmentation::UnicodeSegmentation;
+
 use crate::diag::StrResult;
 use crate::util::EcoString;
 
@@ -41,9 +43,9 @@ impl Str {
         self.0.as_str()
     }
 
-    /// Return an iterator over the chars as strings.
+    /// Return an iterator over the grapheme clusters as strings.
     pub fn iter(&self) -> impl Iterator<Item = Str> + '_ {
-        self.chars().map(Into::into)
+        self.graphemes(true).map(Into::into)
     }
 
     /// Repeat this string `n` times.
diff --git a/tests/typ/code/for.typ b/tests/typ/code/for.typ
index 63dab9b88..2569f5a7f 100644
--- a/tests/typ/code/for.typ
+++ b/tests/typ/code/for.typ
@@ -58,15 +58,15 @@
 
 #test(out, (1, 2, 3, 4, 5, "a", 6, "b", 7))
 
-// Chars of string.
+// Grapheme clusters of string.
 #let first = true
-#let joined = for c in "abc" {
+#let joined = for c in "abc👩‍👩‍👦‍👦" {
   if not first { ", " }
   first = false
   c
 }
 
-#test(joined, "a, b, c")
+#test(joined, "a, b, c, 👩‍👩‍👦‍👦")
 
 // Return value.
 #test(for v in "" [], none)