From 76e1b248555a407c7f99903accb23c09fab3e3ec Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Tue, 16 Mar 2021 14:07:39 -0400
Subject: [PATCH] Highlight multi-line comments

---
 src/document.rs | 38 ++++++++++++++++++++++----------------
 src/row.rs      | 40 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 60 insertions(+), 18 deletions(-)

diff --git a/src/document.rs b/src/document.rs
index a597cd3..169ddc4 100644
--- a/src/document.rs
+++ b/src/document.rs
@@ -17,12 +17,13 @@ impl Document {
     pub fn open(filename: &str) -> Result<Self, std::io::Error> {
         let contents = fs::read_to_string(filename)?;
         let file_type = FileType::from(filename);
+        let mut start_with_comment = false;
 
         let mut rows = Vec::new();
 
         for value in contents.lines() {
             let mut row = Row::from(value);
-            row.highlight(&file_type.highlighting_options(), None);
+            start_with_comment = row.highlight(&file_type.highlighting_options(), None, start_with_comment);
             rows.push(row);
         }
 
@@ -60,20 +61,17 @@ impl Document {
 
         if c == '\n' {
             self.insert_newline(at);
-            return;
-        }
-
-        if at.y == self.rows.len() {
+        } else if at.y == self.rows.len() {
             let mut row = Row::default();
             row.insert(0, c);
-            row.highlight(&self.file_type.highlighting_options(), None);
             self.rows.push(row);
         } else {
             #[allow(clippy::indexing_slicing)]
             let row = &mut self.rows[at.y];
             row.insert(at.x, c);
-            row.highlight(&self.file_type.highlighting_options(), None);
         }
+
+        self.highlight(None);
     }
 
     #[allow(clippy::integer_arithmetic, clippy::indexing_slicing)]
@@ -90,23 +88,28 @@ impl Document {
             let next_row = self.rows.remove(at.y + 1);
             let row = &mut self.rows[at.y];
             row.append(&next_row);
-            row.highlight(&self.file_type.highlighting_options(), None);
         } else {
             let row = &mut self.rows[at.y];
             row.delete(at.x);
-            row.highlight(&self.file_type.highlighting_options(), None);
         }
+
+        self.highlight(None);
     }
 
     pub fn save(&mut self) -> Result<(), Error> {
         if let Some(file_name) = &self.file_name {
             let mut file = fs::File::create(file_name)?;
-
             self.file_type = FileType::from(file_name);
+            let mut start_with_comment = false;
+
             for row in &mut self.rows {
                 file.write_all(row.as_bytes())?;
                 file.write_all(b"\n")?;
-                row.highlight(&self.file_type.highlighting_options(), None)
+                start_with_comment = row.highlight(
+                    &self.file_type.highlighting_options(),
+                    None,
+                    start_with_comment,
+                );
             }
 
             // File has been cleaned! (Saved)
@@ -117,8 +120,14 @@ impl Document {
     }
 
     pub fn highlight(&mut self, word: Option<&str>) {
+        let mut start_with_comment = false;
+
         for row in &mut self.rows {
-            row.highlight(&self.file_type.highlighting_options(), word);
+            start_with_comment = row.highlight(
+                &self.file_type.highlighting_options(),
+                word,
+                start_with_comment,
+            );
         }
     }
 
@@ -173,10 +182,7 @@ impl Document {
 
         #[allow(clippy::indexing_slicing)]
         let current_row = &mut self.rows[at.y];
-        let mut new_row = current_row.split(at.x);
-
-        current_row.highlight(&self.file_type.highlighting_options(), None);
-        new_row.highlight(&self.file_type.highlighting_options(), None);
+        let new_row = current_row.split(at.x);
 
         #[allow(clippy::integer_arithmetic)]
         self.rows.insert(at.y + 1, new_row);
diff --git a/src/row.rs b/src/row.rs
index b67e9f8..08e0c3b 100644
--- a/src/row.rs
+++ b/src/row.rs
@@ -376,7 +376,7 @@ impl Row {
 
                     for _ in *index..closing_index {
                         self.highlighting.push(highlighting::Type::MultilineComment);
-                        *index +=1;
+                        *index += 1;
                     }
 
                     return true;
@@ -450,12 +450,42 @@ impl Row {
         false
     }
 
-    pub fn highlight(&mut self, opts: &HighlightingOptions, word: Option<&str>) {
+    #[allow(clippy::indexing_slicing, clippy::integer_arithmetic)]
+    pub fn highlight(
+        &mut self,
+        opts: &HighlightingOptions,
+        word: Option<&str>,
+        start_with_comment: bool,
+    ) -> bool {
         self.highlighting = Vec::new();
         let chars: Vec<char> = self.string.chars().collect();
         let mut index = 0;
+        let mut in_ml_comment = start_with_comment;
+
+        // Multi-line comments are needy
+        if in_ml_comment {
+            let closing_index = if let Some(closing_index) = self.string.find("*/") {
+                closing_index + 2
+            } else {
+                chars.len()
+            };
+
+            for _ in 0..closing_index {
+                self.highlighting.push(highlighting::Type::MultilineComment);
+            }
+
+            index = closing_index;
+        }
 
         while let Some(c) = chars.get(index) {
+            if self.highlight_multiline_comment(&mut index, &opts, *c, &chars) {
+                in_ml_comment = true;
+
+                continue;
+            }
+
+            in_ml_comment = false;
+
             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)
@@ -472,6 +502,12 @@ impl Row {
         }
 
         self.highlight_match(word);
+
+        if in_ml_comment && &self.string[self.string.len().saturating_sub(2)..] != "*/" {
+            return true;
+        }
+
+        false
     }
 }