Number and search result highlighting

src/editor.rs

@@ -13,11 +13,19 @@ use self::EditorKey::*;
 const KILO_TAB_STOP: usize = 4;
 const KILO_QUIT_TIMES: u8 = 3;
 
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub enum Highlight {
+    Normal,
+    Number,
+    SearchMatch,
+}
+
 /// A representation of a line in the editor
 #[derive(Debug, Default)]
 pub struct EditorRow {
     chars: String,
     render: String,
+    highlight: Vec<Highlight>,
 }
 
 impl EditorRow {
@@ -137,7 +145,14 @@ impl Editor {
         let mut br = BufReader::with_capacity(5, stdin);
 
         let mut first_read = [0; 1];
-        br.read_exact(&mut first_read);
+        match br.read_exact(&mut first_read) {
+            Ok(_) => (),
+            Err(e) => {
+                if e.kind() != io::ErrorKind::UnexpectedEof {
+                    panic!(e);
+                }
+            }
+        }
         let first_str = String::from_utf8(first_read.to_vec());
         if first_str.is_err() {
             return None;
@@ -164,7 +179,14 @@ impl Editor {
         // Match escape sequence
         // --------------------------------------------------------------------
         let mut seq = [0; 4];
-        br.read_exact(&mut seq);
+        match br.read_exact(&mut seq) {
+            Ok(_) => (),
+            Err(e) => {
+                if e.kind() != io::ErrorKind::UnexpectedEof {
+                    panic!(e);
+                }
+            }
+        }
         let seq_str = String::from_utf8(seq.to_vec());
 
         // On error, just continue the input loop
@@ -279,6 +301,31 @@ impl Editor {
         }
     }
 
+    // ------------------------------------------------------------------------
+    // Syntax Highlighting
+    // ------------------------------------------------------------------------
+
+    fn update_syntax(&mut self, index: usize) {
+        let row = &mut self.rows[index];
+        row.highlight = vec![Highlight::Normal; row.render.len()];
+
+        for (x, ch) in row.render.char_indices() {
+            if ch.is_ascii_digit() {
+                row.highlight[x] = Highlight::Number;
+            }
+        }
+    }
+
+    fn syntax_to_color(&self, syntax_type: Highlight) -> i32 {
+        use Highlight::*;
+
+        match syntax_type {
+            Normal => 37,
+            Number => 31, // Red
+            SearchMatch => 34, // Blue
+        }
+    }
+
     // ------------------------------------------------------------------------
     // Input
     // ------------------------------------------------------------------------
@@ -505,6 +552,10 @@ impl Editor {
         self.output_buffer.push_str(str);
     }
 
+    fn append_out_char(&mut self, ch: char) {
+        self.output_buffer.push(ch);
+    }
+
     fn scroll(&mut self) {
         self.render_x = 0;
         if self.cursor_y < self.rows.len() {
@@ -556,15 +607,27 @@ impl Editor {
                     self.append_out("~");
                 }
             } else {
-                let mut len = self.rows[file_row].render.len() - self.col_offset;
-                if len > self.screen_cols {
-                    len = self.screen_cols;
-                }
-
                 let output = self.rows[file_row].render.clone();
-                // let mut output = self.rows[file_row].render.clone();
-                // output.truncate(len);
-                self.append_out(&output[self.col_offset..len]);
+                let mut current_color: i32 = -1;
+
+                for (x, ch) in output.char_indices() {
+                    if self.rows[file_row].highlight[x] == Highlight::Normal {
+                        if current_color != -1 {
+                            self.append_out("\x1b[39m");
+                            current_color = -1;
+                        }
+                        self.append_out_char(ch);
+                    } else {
+                        let color = self.syntax_to_color(self.rows[file_row].highlight[x]);
+                        if color != current_color {
+                            current_color = color;
+                            let code = format!("\x1b[{}m", color);
+                            self.append_out(&code);
+                        }
+                        self.append_out_char(ch);
+                    }
+                }
+                self.append_out("\x1b[39m");
             }
 
             self.append_out("\x1b[K");
@@ -672,9 +735,8 @@ impl Editor {
     fn row_cx_to_rx(&mut self, index: usize, cx: usize) -> usize {
         let mut rx: usize = 0;
         let mut i: usize = 0;
-        let row = &mut self.rows[index];
 
-        for char in row.chars.chars() {
+        for char in self.rows[index].chars.chars() {
             if char == '\t' {
                 rx += (KILO_TAB_STOP - 1) - (rx % KILO_TAB_STOP);
             } else {
@@ -694,9 +756,8 @@ impl Editor {
     fn row_rx_to_cx(&mut self, index: usize, rx: usize) -> usize {
         let mut current_rx: usize = 0;
         let mut cx: usize = 0;
-        let row = &mut self.rows[index];
 
-        for char in row.chars.chars() {
+        for char in self.rows[index].chars.chars() {
             if char == '\t' {
                 current_rx += (KILO_TAB_STOP - 1) - (current_rx % KILO_TAB_STOP);
             } else {
@@ -721,6 +782,8 @@ impl Editor {
         // Cheat at rendering tabs as spaces
         let str = str.replace('\t', "    ");
         row.render = str;
+
+        self.update_syntax(index);
     }
 
     fn insert_row(&mut self, at: usize, row: &str) {
@@ -938,8 +1001,7 @@ impl Editor {
                 current = 0;
             }
 
-            let row = &self.rows[current as usize];
-            match row.render.find(query) {
+            match self.rows[current as usize].render.find(query) {
                 None => (),
                 Some(start) => {
                     self.search_last_match = current;
@@ -947,6 +1009,12 @@ impl Editor {
                     self.cursor_x = self.row_rx_to_cx(x, start);
                     self.row_offset = self.rows.len();
 
+                    // Highlight matching search result
+                    let len = start + query.len();
+                    for x in start..len {
+                        self.rows[current as usize].highlight[x] = Highlight::SearchMatch;
+                    }
+
                     break;
                 }
             }
@@ -959,7 +1027,7 @@ impl Editor {
         let saved_coloff = self.col_offset;
         let saved_rowoff = self.row_offset;
 
-        let query = self.prompt("Search (ESC to cancel):", Some(&mut Self::find_callback));
+        let query = self.prompt("Search (Use ESC/Arrows/Enter):", Some(&mut Self::find_callback));
 
         if query.is_empty() {
             self.cursor_x = saved_cx;