message: Remove unnecessary code in `Value`
diff: use crate::Length;
  -use std::ops::{Index, RangeTo};
  -
  pub struct TextInput<'a, Message> {
  pub state: &'a mut State,
  pub placeholder: String,
  @@ -93,13 +91,6 @@ impl State {
  Self::default()
  }
  - pub fn focused() -> Self {
  - Self {
  - is_focused: true,
  - ..Self::default()
  - }
  - }
  -
  pub fn move_cursor_right(&mut self, value: &Value) {
  let current = self.cursor_position(value);
  @@ -134,7 +125,7 @@ impl Value {
  }
  pub fn until(&self, index: usize) -> Self {
  - Self(self.0[..index].iter().cloned().collect())
  + Self(self.0[..index.min(self.len())].iter().cloned().collect())
  }
  pub fn to_string(&self) -> String {
  @@ -155,11 +146,3 @@ impl Value {
  self.0.remove(index);
  }
  }
  -
  -impl Index<RangeTo<usize>> for Value {
  - type Output = [char];
  -
  - fn index(&self, index: RangeTo<usize>) -> &[char] {
  - &self.0[index]
  - }
  -}
  