split readline into it's own module directory

src/prompt/readline/line.rs

@@ -0,0 +1,99 @@
+
+#[derive(Default,Debug)]
+pub struct LineBuf {
+	pub buffer: Vec<char>,
+	cursor: usize
+}
+
+impl LineBuf {
+	pub fn new() -> Self {
+		Self::default()
+	}
+	pub fn count_lines(&self) -> usize {
+		self.buffer.iter().filter(|&&c| c == '\n').count()
+	}
+	pub fn cursor(&self) -> usize {
+		self.cursor
+	}
+	pub fn clear(&mut self) {
+		self.buffer.clear();
+		self.cursor = 0;
+	}
+	pub fn insert_at_cursor(&mut self, ch: char) {
+		self.buffer.insert(self.cursor, ch);
+		self.move_cursor_right();
+	}
+	pub fn backspace_at_cursor(&mut self) {
+		assert!(self.cursor <= self.buffer.len());
+		if self.buffer.is_empty() {
+			return
+		}
+		self.buffer.remove(self.cursor.saturating_sub(1));
+		self.move_cursor_left();
+	}
+	pub fn del_at_cursor(&mut self) {
+		assert!(self.cursor <= self.buffer.len());
+		if self.buffer.is_empty() || self.cursor == self.buffer.len() {
+			return
+		}
+		self.buffer.remove(self.cursor);
+	}
+	pub fn move_cursor_left(&mut self) {
+		self.cursor = self.cursor.saturating_sub(1);
+	}
+	pub fn move_cursor_start(&mut self) {
+		self.cursor = 0;
+	}
+	pub fn move_cursor_end(&mut self) {
+		self.cursor = self.buffer.len();
+	}
+	pub fn move_cursor_right(&mut self) {
+		if self.cursor == self.buffer.len() {
+			return
+		}
+		self.cursor = self.cursor.saturating_add(1);
+	}
+	pub fn del_from_cursor(&mut self) {
+		self.buffer.truncate(self.cursor);
+	}
+	pub fn del_word_back(&mut self) {
+		if self.cursor == 0 {
+			return 
+		}
+		let end = self.cursor;
+		let mut start = self.cursor;
+
+		while start > 0 && self.buffer[start - 1].is_whitespace() {
+			start -= 1;
+		}
+
+		while start > 0 && !self.buffer[start - 1].is_whitespace() {
+			start -= 1;
+		}
+
+		self.buffer.drain(start..end);
+		self.cursor = start;
+	}
+}
+
+pub fn strip_ansi_codes(s: &str) -> String {
+	let mut out = String::with_capacity(s.len());
+	let mut chars = s.chars().peekable();
+
+	while let Some(c) = chars.next() {
+		if c == '\x1b' && chars.peek() == Some(&'[') {
+			// Skip over the escape sequence
+			chars.next(); // consume '['
+			while let Some(&ch) = chars.peek() {
+				if ch.is_ascii_lowercase() || ch.is_ascii_uppercase() {
+					chars.next(); // consume final letter
+					break;
+				}
+				chars.next(); // consume intermediate characters
+			}
+		} else {
+			out.push(c);
+		}
+	}
+	out
+}