/// Parse a string into a `Keypad`.
///
/// Expect `s` to be a keypad grid representation where ASCII spaces (0x20) are skipped
/// (but not ignored) zones of the size of a button and all other characters are buttons.
/// All non-space characters must be unique through the representation.
///
/// # Examples
///
/// A classic keypad (with buttons from 1 to 9 as any sane person would picture)
/// representation look like this:
///
/// ```text
/// 123
/// 456
/// 789
/// ```
///
/// A keypad from hell resulting of hundreds of man-hours of bathroom-keypad-design
/// meetings representation look like this:
///
/// ```text
///   1
///  234
/// 56789
///  ABC
///   D
/// ```
Parse a string into a `Keypad`.
Expect `s` to be a keypad grid representation where ASCII spaces (0x20) are skipped
(but not ignored) zones of the size of a button and all other characters are buttons.
All non-space characters must be unique through the representation.
Parse a string into a ` Keypad ` . Expect ` s ` to be a keypad grid representation where ASCII spaces ( 0x20 ) are skipped ( but not ignored ) zones of the size of a button and all other characters are buttons . All non - space characters must be unique through the representation .
fn from_str(s: &str) -> Result<Keypad, String> {
            let mut buttons_to_positions: HashMap<KeypadButton, Point> = HashMap::new();
            let mut positions_to_buttons: HashMap<Point, KeypadButton> = HashMap::new();
            for (y, line) in s.lines().enumerate() {
                for (x, c) in line.chars().enumerate() {
                    // skip if we're on a blank space, it is a non-button position.
                    if c == ' ' {
                        continue;
                    }
                    // NOTE: we want to be able to create `Point` that are beyond the keyboard grid
                    // (off-by-one, see neighbour_of()), hence checking for (x + 1) and (y + 1).
                    if x + 1 > ::std::i32::MAX as usize || y + 1 > ::std::i32::MAX as usize {
                        return Err("insanely big keyboard string representation".to_string());
                    }
                    // (x as i32) and (y as i32) are safe now that we checked against
                    // std::i32::MAX.
                    let position = Point {
                        x: x as i32,
                        y: y as i32,
                    };
                    let button = KeypadButton(c);
                    if buttons_to_positions.insert(button, position).is_some() {
                        return Err(format!("{:?}: already exist", button));
                    }
                    positions_to_buttons.insert(position, button);
                }
            }
            Ok(Keypad {
                positions_to_buttons: positions_to_buttons,
                buttons_to_positions: buttons_to_positions,
                pressed: KeypadButtonSequence(Vec::new()),
            })
        }
fn from_str ( s : & str ) -> Result < Keypad , String > { let mut buttons_to_positions : HashMap < KeypadButton , Point > = HashMap :: new ( ) ; let mut positions_to_buttons : HashMap < Point , KeypadButton > = HashMap :: new ( ) ; for ( y , line ) in s . lines ( ) . enumerate ( ) { for ( x , c ) in line . chars ( ) . enumerate ( ) { // skip if we're on a blank space, it is a non-button position. if c == ' ' { continue ; } // NOTE: we want to be able to create `Point` that are beyond the keyboard grid // (off-by-one, see neighbour_of()), hence checking for (x + 1) and (y + 1). if x + 1 > :: std :: i32 :: MAX as usize || y + 1 > :: std :: i32 :: MAX as usize { return Err ( " " . to_string ( ) ) ; } // (x as i32) and (y as i32) are safe now that we checked against // std::i32::MAX. let position = Point { x : x as i32 , y : y as i32 , } ; let button = KeypadButton ( c ) ; if buttons_to_positions . insert ( button , position ) . is_some ( ) { return Err ( format ! ( " " button ) ) ; } positions_to_buttons . insert ( position , button ) ; } } Ok ( Keypad { positions_to_buttons : positions_to_buttons , buttons_to_positions : buttons_to_positions , pressed : KeypadButtonSequence ( Vec :: new ( ) ) , } ) }
Parse a string into a `Keypad`.
Parse a string into a ` Keypad ` .
s
&str
examples
A classic keypad (with buttons from 1 to 9 as any sane person would picture)
representation look like this.



A keypad from hell resulting of hundreds of man-hours of bathroom-keypad-design
meetings representation look like this.


A classic keypad ( with buttons from 1 to 9 as any sane person would picture ) representation look like this . A keypad from hell resulting of hundreds of man - hours of bathroom - keypad - design meetings representation look like this .