Struct rouler::Roller

pub struct Roller<'a> { /* fields omitted */ }

The Roller is the core struct of the library. The basic principle is to provide a reusable container that provides a specific kind of die roll, so that it can be quickly and easily repeated whenever called for. Each container contains the syntax of the roll type it represents, and the value of the last roll it made. Containers are thus self-mutating, but self-contained.

The main benefit is thus in code organization, as one can store different types of rolls for easy use later.

Methods

impl<'a> Roller<'a>

fn new(roll: &'a str) -> Self

Creates a new Roller with the given die roll syntax, and populates the stored total with a first roll of the indicated dice. Because subsequent rerolls mutate the object in order to store the most recent roll, it should be declared with let mut if you intend to reroll it.

Panics

As a Roller rolls itself on creation, it thus triggers the parser, and incorrect syntax will cause a panic.

Examples

use rouler::Roller;

let mut laser_damage = Roller::new("1d4*10");

println!("Damage, rnd 1: {}", laser_damage.total());
println!("Damage, rnd 2: {}", laser_damage.reroll());

Rollers implement Eq and Ord, based on their current totals, so die results can be compared directly without having to first call the total method:

let att = Roller::new("1d20 + 5");
let def = Roller::new("1d20 + 2");
 
if att > def {
    println!("You struck the monster!");        
} else {
    println!("You missed!");
}

For convenience's sake, Rollers also implement Display, so they are printable:

println!("{}", Roller::new("4d8 + 5"));
// => [4d8 + 5: 24]

fn reroll(&mut self) -> i64

Rolls the Roller's die roll, stores the value in total, and then returns it. In this way, you can use Roller::reroll() in place as a value, rather than needing to call the method seperately.

Examples

use rouler::Roller;

let mut stat = Roller::new("3d6");

println!("STR (3d6): {}", stat.total());        // => STR (3d6): 14
println!("DEX (3d6+1): {}", stat.reroll() + 1); // => DEX (3d6+1): 13

println!("{}", stat);                           // prints [3d6: 12]

fn total(&self) -> i64

Returns the result of the last roll made by the Roller.

fn iter(&mut self) -> &mut Self

Returns a reference to self for use as an Iterator. This allows for iterating infinitely and lazily over successive rolls of the dice. By borrowing as mutable, the state of the internal total is preserved, so that calls to total() will remain consistent.

Examples

// Collect multiple results to a vector:
let stats = Roller::new("3d6").iter().take(6).collect::<Vec<i64>>();

Remember! Rollers are infinite iterators: always use take() to avoid infinite loops! This is safe:

// Keep rolling until a result greater than a threshold:
assert!(Roller::new("4d6").iter().skip_while(|&x| x < 13).take(1).last().unwrap() >= 13);

But this will not terminate:

assert!(Roller::new("4d6").iter().skip_while(|&x| x < 13).last().unwrap() >= 13);

Trait Implementations

impl<'a> Debug for Roller<'a>

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'a> Clone for Roller<'a>

fn clone(&self) -> Roller<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Copy for Roller<'a>

impl<'a> Iterator for Roller<'a>

type Item = i64

The type of the elements being iterated over.

fn next(&mut self) -> Option<i64>

Advances the iterator and returns the next value.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator.

fn count(self) -> usize

Consumes the iterator, counting the number of iterations and returning it.

fn last(self) -> Option<Self::Item>

Consumes the iterator, returning the last element.

fn nth(&mut self, n: usize) -> Option<Self::Item>

Returns the nth element of the iterator.

fn step_by(self, step: usize) -> StepBy<Self>

🔬 This is a nightly-only experimental API. (iterator_step_by)

unstable replacement of Range::step_by

Creates an iterator starting at the same point, but stepping by the given amount at each iteration.

fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator<Item = Self::Item>, 

Takes two iterators and creates a new iterator over both in sequence.

fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
    U: IntoIterator, 

'Zips up' two iterators into a single iterator of pairs.

fn map<B, F>(self, f: F) -> Map<Self, F> where
    F: FnMut(Self::Item) -> B, 

Takes a closure and creates an iterator which calls that closure on each element.

fn filter<P>(self, predicate: P) -> Filter<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator which uses a closure to determine if an element should be yielded.

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
    F: FnMut(Self::Item) -> Option<B>, 

Creates an iterator that both filters and maps.

fn enumerate(self) -> Enumerate<Self>

Creates an iterator which gives the current iteration count as well as the next value.

fn peekable(self) -> Peekable<Self>

Creates an iterator which can use peek to look at the next element of the iterator without consuming it.

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that [skip]s elements based on a predicate.

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
    P: FnMut(&Self::Item) -> bool, 

Creates an iterator that yields elements based on a predicate.

fn skip(self, n: usize) -> Skip<Self>

Creates an iterator that skips the first n elements.

fn take(self, n: usize) -> Take<Self>

Creates an iterator that yields its first n elements.

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
    F: FnMut(&mut St, Self::Item) -> Option<B>, 

An iterator adaptor similar to [fold] that holds internal state and produces a new iterator.

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
    F: FnMut(Self::Item) -> U,
    U: IntoIterator, 

Creates an iterator that works like map, but flattens nested structure.

fn fuse(self) -> Fuse<Self>

Creates an iterator which ends after the first [None].

fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnMut(&Self::Item) -> (), 

Do something with each element of an iterator, passing the value on.

fn by_ref(&mut self) -> &mut Self

Borrows an iterator, rather than consuming it.

fn collect<B>(self) -> B where
    B: FromIterator<Self::Item>, 

Transforms an iterator into a collection.

fn partition<B, F>(self, f: F) -> (B, B) where
    B: Default + Extend<Self::Item>,
    F: FnMut(&Self::Item) -> bool, 

Consumes an iterator, creating two collections from it.

fn fold<B, F>(self, init: B, f: F) -> B where
    F: FnMut(B, Self::Item) -> B, 

An iterator adaptor that applies a function, producing a single, final value.

fn all<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if every element of the iterator matches a predicate.

fn any<F>(&mut self, f: F) -> bool where
    F: FnMut(Self::Item) -> bool, 

Tests if any element of the iterator matches a predicate.

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
    P: FnMut(&Self::Item) -> bool, 

Searches for an element of an iterator that satisfies a predicate.

fn position<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool, 

Searches for an element in an iterator, returning its index.

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where
    P: FnMut(Self::Item) -> bool,
    Self: ExactSizeIterator + DoubleEndedIterator, 

Searches for an element in an iterator from the right, returning its index.

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the maximum element of an iterator.

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Returns the minimum element of an iterator.

fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 

Returns the element that gives the maximum value from the specified function.

fn max_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the maximum value with respect to the specified comparison function.

fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
    B: Ord,
    F: FnMut(&Self::Item) -> B, 

Returns the element that gives the minimum value from the specified function.

fn min_by<F>(self, compare: F) -> Option<Self::Item> where
    F: FnMut(&Self::Item, &Self::Item) -> Ordering, 

Returns the element that gives the minimum value with respect to the specified comparison function.

fn rev(self) -> Rev<Self> where
    Self: DoubleEndedIterator, 

Reverses an iterator's direction.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where
    FromA: Default + Extend<A>,
    FromB: Default + Extend<B>,
    Self: Iterator<Item = (A, B)>, 

Converts an iterator of pairs into a pair of containers.

fn cloned<'a, T>(self) -> Cloned<Self> where
    Self: Iterator<Item = &'a T>,
    T: 'a + Clone, 

Creates an iterator which [clone]s all of its elements.

fn cycle(self) -> Cycle<Self> where
    Self: Clone, 

Repeats an iterator endlessly.

fn sum<S>(self) -> S where
    S: Sum<Self::Item>, 

Sums the elements of an iterator.

fn product<P>(self) -> P where
    P: Product<Self::Item>, 

Iterates over the entire iterator, multiplying all the elements

fn cmp<I>(self, other: I) -> Ordering where
    I: IntoIterator<Item = Self::Item>,
    Self::Item: Ord, 

Lexicographically compares the elements of this Iterator with those of another.

fn partial_cmp<I>(self, other: I) -> Option<Ordering> where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Lexicographically compares the elements of this Iterator with those of another.

fn eq<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are equal to those of another.

fn ne<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialEq<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are unequal to those of another.

fn lt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically less or equal to those of another.

fn gt<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool where
    I: IntoIterator,
    Self::Item: PartialOrd<<I as IntoIterator>::Item>, 

Determines if the elements of this Iterator are lexicographically greater than or equal to those of another.

impl<'a> PartialEq for Roller<'a>

fn eq(&self, other: &Roller) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a> Eq for Roller<'a>

impl<'a> Ord for Roller<'a>

fn cmp(&self, other: &Roller) -> Ordering

This method returns an Ordering between self and other.

impl<'a> PartialOrd for Roller<'a>

fn partial_cmp(&self, other: &Roller) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> Display for Roller<'a>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.