Build up highlighting array

src/document.rs

@@ -18,7 +18,9 @@ impl Document {
         let mut rows = Vec::new();
 
         for value in contents.lines() {
-            rows.push(Row::from(value));
+            let mut row = Row::From(value);
+            row.highlight();
+            rows.push(row);
         }
 
         Ok(Self {
@@ -56,11 +58,13 @@ impl Document {
         if at.y == self.rows.len() {
             let mut row = Row::default();
             row.insert(0, c);
+            row.highlight();
             self.rows.push(row);
         } else {
             #[allow(clippy::indexing_slicing)]
             let row = &mut self.rows[at.y];
             row.insert(at.x, c);
+            row.highlight();
         }
     }
 
@@ -78,9 +82,11 @@ impl Document {
             let next_row = self.rows.remove(at.y + 1);
             let row = &mut self.rows[at.y];
             row.append(&next_row);
+            row.highlight();
         } else {
             let row = &mut self.rows[at.y];
             row.delete(at.x);
+            row.highlight();
         }
     }
 
@@ -150,8 +156,12 @@ impl Document {
         }
 
         #[allow(clippy::indexing_slicing)]
+        let current_row = &mut self.rows[at.y];
         let new_row = self.rows[at.y].split(at.x);
 
+        current_row.highlight();
+        new_row.highlight();
+
         #[allow(clippy::integer_arithmetic)]
         self.rows.insert(at.y + 1, new_row);
     }

src/highlighting.rs

@@ -0,0 +1,15 @@
+use termion::color;
+
+pub enum Type {
+    None,
+    Number,
+}
+
+impl Type {
+    pub fn to_color(&self) -> impl color::Color {
+        match self {
+            Type::Number => color::Rgb(220, 163, 163),
+            _ => color::Rgb(255, 255, 255),
+        }
+    }
+}

src/main.rs

@@ -2,6 +2,7 @@
 #![allow(clippy::missing_errors_doc, clippy::must_use_candidate, clippy::panic)]
 mod document;
 mod editor;
+mod highlighting;
 mod row;
 mod terminal;
 

src/row.rs

@@ -1,3 +1,4 @@
+use crate::highlighting;
 use crate::SearchDirection;
 use std::cmp;
 use termion::color;
@@ -6,6 +7,7 @@ use unicode_segmentation::UnicodeSegmentation;
 #[derive(Default)]
 pub struct Row {
     string: String,
+    highlighting: Vec<highlighting::Type>,
     len: usize,
 }
 
@@ -13,6 +15,7 @@ impl From<&str> for Row {
     fn from(slice: &str) -> Self {
         Self {
             string: String::from(slice),
+            highlighting: Vec::new(),
             len: slice.graphemes(true).count(),
         }
     }
@@ -133,6 +136,7 @@ impl Row {
         Self {
             string: splitted_row,
             len: splittend_length,
+            highlighting: Vec::new(),
         }
     }
 
@@ -174,4 +178,18 @@ impl Row {
 
         None
     }
+
+    pub fn highlight(&mut self) {
+        let mut highlighting = Vec::new();
+
+        for c in self.string.chars() {
+            if c.is_ascii_digit() {
+                highlighting.push(highlighting::Type::Number)
+            } else {
+                highlighting.push(highlighting::Type::None)
+            }
+        }
+
+        self.highlighting = highlighting;
+    }
 }