[][src]Struct turtle::Speed

pub struct Speed(_);

Represents both the movement and rotation speed of the turtle.

Creating Speeds

You can create a Speed value by converting either strings or numbers.

// This value is of type `Speed` and it is converted from an `i32`
let speed: Speed = 1.into();

// This value is of type `Speed` and it is converted from a `&str`
let slowest_speed: Speed = "slowest".into();

There is no need to call .into() when passing a speed into the set_speed method. See the set_speed method for more information about how that works.

let mut turtle = Turtle::new();
turtle.set_speed(22); // Same as `turtle.set_speed(22.into())`

The minimum speed value is 1 and the maximum speed value (currently) is 25.

Trying to set the speed to a value out of that range will cause a panic.

let mut turtle = Turtle::new();
turtle.set_speed(26); // panic!

While the minimum speed will not change, the maximum speed may grow larger if the need arises. That is why we chose to panic for invalid speeds instead of defaulting to another value.

String Conversion

Strings are converted as follows:

"instant"see below

You can use strings to create Speed values in the same way numbers were used above. Each of the following is an equivalent way to set the speed to 5:

turtle.set_speed(Speed::from(5)); // Not recommended!
turtle.set_speed(Speed::from("slower")); // Not recommended!


There is one special speed value "instant" which makes it so that movement and rotation are not animated at all. Instead, the turtle immediately moves and rotates to the position that you directed it to. It will still draw along the way if its pen is down.

let mut turtle = Turtle::new();
turtle.forward(100.0); // A line will be drawn instantly!

Comparing Speed Values

Speed values can be compared for equality with i32 values. This is a little more convenient than converting the i32 to Speed every time you want to make a comparison.

let speed: Speed = 1.into();
// Speed values can be compared to integers
assert_eq!(speed, 1);
// This is equivalent to the following
assert_eq!(speed, Speed::from(1));

// This value is of type `Speed` and it is converted from a `&str`
let speed: Speed = "slowest".into();
// Speed values can be compared to other speed values
assert_eq!(speed, Speed::from("slowest"));
// This is equivalent to the following since the slowest speed is 1
assert_eq!(speed, 1);

You can use the <, <=, ==, >=, > with Speed values and i32 values (or other Speed values).

let turtle = Turtle::new();
let speed = turtle.speed();
if speed == 12 && speed >= 5 && speed < Speed::instant() {
    println!("Super fast!!");
// This is equivalent, but requires more typing
if speed == Speed::from(12) && speed >= Speed::from(5) && speed < Speed::from("instant") {
    println!("Super fast!!");

Notice that you can compare Speed values to numeric values, but not the other way around.

This example deliberately fails to compile
let speed: Speed = 7.into();
if 8 > speed { // This doesn't make sense and won't compile!
    // ...

To check if a speed is instant, use the is_instant() method or compare the speed to Speed::instant().

let speed = Speed::instant();
if speed.is_instant() {


impl Speed[src]

pub fn instant() -> Self[src]

Returns the speed value that will make the turtle move and rotate instantly. This means that instead of the turtle's movements being animated, it will directly move to wherever you direct it to go.

let mut turtle = Turtle::new();
turtle.forward(100.0); // A line will be drawn instantly!

Whenever possible, you should prefer to use the string "instant" instead of calling this method.

turtle.set_speed("instant"); // equivalent to typing `Speed::instant()`

pub fn is_instant(self) -> bool[src]

Returns true if this speed is the same as Speed::instant()

use turtle::{Speed};
let speed: Speed = "instant".into();

let speed = Speed::instant();

Trait Implementations

impl Random for Speed[src]

fn random() -> Self[src]

Generates a random speed within the valid range of speed levels

impl<B: Into<Speed>> RandomRange<B> for Speed[src]

fn random_range(low: B, high: B) -> Self[src]

Generates a random difficulty level within the given range, not including instant.


Panics if either bound could result in a value outside the valid range of speed levels or if low > high. Also panics if either bound is Speed::instant().

impl<'a> From<&'a str> for Speed[src]

impl From<i32> for Speed[src]

impl From<f64> for Speed[src]

impl Clone for Speed[src]

impl Copy for Speed[src]

impl Eq for Speed[src]

impl Ord for Speed[src]

impl PartialEq<Speed> for Speed[src]

impl PartialEq<i32> for Speed[src]

impl PartialOrd<Speed> for Speed[src]

impl PartialOrd<i32> for Speed[src]

impl Debug for Speed[src]

impl Display for Speed[src]

impl Hash for Speed[src]

impl StructuralPartialEq for Speed[src]

impl StructuralEq for Speed[src]

impl Serialize for Speed[src]

impl<'de> Deserialize<'de> for Speed[src]

Auto Trait Implementations

impl Send for Speed

impl Sync for Speed

impl Unpin for Speed

impl UnwindSafe for Speed

impl RefUnwindSafe for Speed

Blanket Implementations

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 

impl<T> ToOwned for T where
    T: Clone

type Owned = T

The resulting type after obtaining ownership.

impl<T> ToString for T where
    T: Display + ?Sized

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 

type Error = !

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> Borrow<T> for T where
    T: ?Sized

impl<T> BorrowMut<T> for T where
    T: ?Sized

impl<T> Any for T where
    T: 'static + ?Sized

impl<T> DeserializeOwned for T where
    T: Deserialize<'de>, 

impl<T> SetParameter for T