From 62df35a7513e4cdca0f3eef4698bcf7cca2d2ea2 Mon Sep 17 00:00:00 2001
From: Timothy Warren <tim@timshomepage.net>
Date: Tue, 16 Mar 2021 13:38:50 -0400
Subject: [PATCH] Highlight first line of multi-line comments

---
 src/editor.rs   |  5 +++++
 src/filetype.rs |  2 +-
 src/row.rs      | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/editor.rs b/src/editor.rs
index e47bf19..471dc8a 100644
--- a/src/editor.rs
+++ b/src/editor.rs
@@ -24,11 +24,15 @@ pub struct Position {
     pub y: usize,
 }
 
+/** The message to display on the status line */
 struct StatusMessage {
     text: String,
     time: Instant,
 }
 
+/**
+ * Add methods to the StatusMessage
+ */
 impl StatusMessage {
     fn default() -> Self {
         Self::from("")
@@ -42,6 +46,7 @@ impl StatusMessage {
     }
 }
 
+/// The main editor object
 pub struct Editor {
     should_quit: bool,
     terminal: Terminal,
diff --git a/src/filetype.rs b/src/filetype.rs
index e09d8a0..ab8c770 100644
--- a/src/filetype.rs
+++ b/src/filetype.rs
@@ -147,6 +147,6 @@ impl HighlightingOptions {
     }
 
     pub fn multiline_comments(&self) -> bool {
-        &self.multiline_comments
+        self.multiline_comments
     }
 }
diff --git a/src/row.rs b/src/row.rs
index f2133eb..b67e9f8 100644
--- a/src/row.rs
+++ b/src/row.rs
@@ -356,6 +356,37 @@ impl Row {
         false
     }
 
+    #[allow(clippy::indexing_slicing, clippy::integer_arithmetic)]
+    fn highlight_multiline_comment(
+        &mut self,
+        index: &mut usize,
+        opts: &HighlightingOptions,
+        c: char,
+        chars: &[char],
+    ) -> bool {
+        if opts.multiline_comments() && c == '/' && *index < chars.len() {
+            if let Some(next_char) = chars.get(index.saturating_add(1)) {
+                if *next_char == '*' {
+                    let closing_index =
+                        if let Some(closing_index) = self.string[*index + 2..].find("*/") {
+                            *index + closing_index + 4
+                        } else {
+                            chars.len()
+                        };
+
+                    for _ in *index..closing_index {
+                        self.highlighting.push(highlighting::Type::MultilineComment);
+                        *index +=1;
+                    }
+
+                    return true;
+                }
+            }
+        }
+
+        false
+    }
+
     fn highlight_string(
         &mut self,
         index: &mut usize,
@@ -427,6 +458,7 @@ impl Row {
         while let Some(c) = chars.get(index) {
             if self.highlight_char(&mut index, opts, *c, &chars)
                 || self.highlight_comment(&mut index, opts, *c, &chars)
+                || self.highlight_multiline_comment(&mut index, opts, *c, &chars)
                 || self.highlight_primary_keywords(&mut index, &opts, &chars)
                 || self.highlight_secondary_keywords(&mut index, &opts, &chars)
                 || self.highlight_string(&mut index, opts, *c, &chars)