Add syntax highlighting to editor and logs

Introduce a `highlight_myc` function to provide syntax highlighting for
the source code editor and trace logs, improving code readability.

src/main.rs

@@ -348,12 +348,18 @@ impl eframe::App for CompilerApp {
                             },
                             AppTab::Trace => {
                                 let mut combined = self.trace_logs.join("\n");
+                                let mut layouter = |ui: &egui::Ui, buffer: &dyn egui::TextBuffer, _wrap_width: f32| {
+                                    let layout_job = highlight_myc(ui.ctx(), buffer.as_str());
+                                    ui.painter().layout_job(layout_job)
+                                };
+
                                 ui.add_sized(
                                     ui.available_size(),
                                     egui::TextEdit::multiline(&mut combined)
                                         .font(egui::TextStyle::Monospace)
                                         .desired_width(f32::INFINITY)
                                         .interactive(false)
+                                        .layouter(&mut layouter)
                                 );
                             }
                         }
@@ -387,15 +393,110 @@ impl eframe::App for CompilerApp {
             egui::ScrollArea::vertical()
                 .id_salt("source_code_scroll")
                 .show(ui, |ui| {
+                    let mut layouter = |ui: &egui::Ui, buffer: &dyn egui::TextBuffer, _wrap_width: f32| {
+                        let layout_job = highlight_myc(ui.ctx(), buffer.as_str());
+                        ui.painter().layout_job(layout_job)
+                    };
+
                     ui.add_sized(
                         ui.available_size(),
                         egui::TextEdit::multiline(&mut self.source_code)
                             .id(editor_id)
                             .font(egui::TextStyle::Monospace)
                             .desired_width(f32::INFINITY)
-                            .lock_focus(true),
+                            .lock_focus(true)
+                            .layouter(&mut layouter),
                     );
                 });
         });
     }
 }
+
+fn highlight_myc(ctx: &egui::Context, code: &str) -> egui::text::LayoutJob {
+    let mut job = egui::text::LayoutJob::default();
+    let theme = &ctx.style().visuals;
+    
+    let color_kw = egui::Color32::from_rgb(86, 156, 214);   // Blue
+    let color_str = egui::Color32::from_rgb(206, 145, 120);  // Orange/Brown
+    let color_num = egui::Color32::from_rgb(181, 206, 168);  // Greenish
+    let color_comment = egui::Color32::from_rgb(106, 153, 85); // Green
+    let color_bracket = [
+        egui::Color32::from_rgb(255, 215, 0),   // Gold
+        egui::Color32::from_rgb(218, 112, 214), // Orchid
+        egui::Color32::from_rgb(24, 131, 215),  // Blue
+    ];
+
+    let mut chars = code.chars().peekable();
+    let mut bracket_depth = 0;
+
+    while let Some(c) = chars.next() {
+        let mut text = String::from(c);
+        let mut color = theme.widgets.noninteractive.text_color();
+
+        match c {
+            ';' => {
+                while let Some(&next) = chars.peek() {
+                    if next == '\n' { break; }
+                    text.push(chars.next().unwrap());
+                }
+                color = color_comment;
+            }
+            '"' => {
+                while let Some(next) = chars.next() {
+                    text.push(next);
+                    if next == '"' { break; }
+                    if next == '\\' {
+                        if let Some(escaped) = chars.next() { text.push(escaped); }
+                    }
+                }
+                color = color_str;
+            }
+            ':' => {
+                while let Some(&next) = chars.peek() {
+                    if next.is_whitespace() || "()[]{}".contains(next) { break; }
+                    text.push(chars.next().unwrap());
+                }
+                color = color_kw;
+            }
+            '(' | '[' | '{' => {
+                color = color_bracket[bracket_depth % 3];
+                bracket_depth += 1;
+            }
+            ')' | ']' | '}' => {
+                if bracket_depth > 0 { bracket_depth -= 1; }
+                color = color_bracket[bracket_depth % 3];
+            }
+            '0'..='9' => {
+                while let Some(&next) = chars.peek() {
+                    if next.is_ascii_digit() || next == '.' {
+                        text.push(chars.next().unwrap());
+                    } else { break; }
+                }
+                color = color_num;
+            }
+            _ if c.is_alphabetic() || "+-*/<=>!$%&_?.".contains(c) => {
+                while let Some(&next) = chars.peek() {
+                    if next.is_alphanumeric() || "+-*/<=>!$%&_?.".contains(next) {
+                        text.push(chars.next().unwrap());
+                    } else { break; }
+                }
+                if ["fn", "def", "do", "if", "assign", "recur", "cond"].contains(&text.as_str()) {
+                    color = color_kw;
+                }
+            }
+            _ => {}
+        }
+
+        job.append(
+            &text,
+            0.0,
+            egui::TextFormat {
+                font_id: egui::FontId::monospace(14.0),
+                color,
+                ..Default::default()
+            },
+        );
+    }
+
+    job
+}