Trait zero_sum::analysis::Evaluation

pub trait Evaluation: Sized + Clone + Copy + Display + Add<Output = Self> + Sub<Output = Self> + Mul<Output = Self> + Neg<Output = Self> + Div<Output = Self> + PartialEq + PartialOrd {
    fn null() -> Self;
    fn shift(self, steps: i32) -> Self;
    fn win() -> Self;
    fn max() -> Self;
    fn is_win(&self) -> bool;

    fn lose() -> Self { ... }
    fn min() -> Self { ... }
    fn is_lose(&self) -> bool { ... }
    fn is_end(&self) -> bool { ... }
}

An evaluation type.

This is usually a tuple around a signed numeric type.

Example

There is a helper macro to facilitate the implementation of tuple structs:

#[macro_use]
extern crate zero_sum;
use std::i32;
use std::ops::{Add, Div, Mul, Neg, Sub};

#[derive(Clone, Copy, PartialEq, PartialOrd)]
struct Eval(i32);

prepare_evaluation_tuple!(Eval); // impl Add, Div, Mul, Neg, Sub, and Display

impl Evaluation for Eval {
    fn null() -> Eval { Eval(0) }
    fn shift(self, steps: i32) -> Eval { Eval(self.0 + steps) }
    fn win() -> Eval { Eval(100000) }
    fn max() -> Eval { Eval(i32::MAX) }
    fn is_win(&self) -> bool { self.0 > 99000 }
}

Required Methods

fn null() -> Self

An empty, or zero evaluation.

fn shift(self, steps: i32) -> Self

Shift the evaluation by the smallest representable amount steps times in the positive or negative direction.

fn win() -> Self

The base value of a win. The evaluator may add or subtract to it in in order to promote it or discourage it in favor of others in the search.

fn max() -> Self

The maximum value representable. This must be safely negatable.

fn is_win(&self) -> bool

Returns true if this evaluation contains a win. This is usually a check to see if the value is above a certain threshold.

Provided Methods

fn lose() -> Self

The base value of a loss. The evaluator may add or subtract to it in in order to promote it or discourage it in favor of others in the search.

fn min() -> Self

The minimum value representable.

fn is_lose(&self) -> bool

Returns true if this evaluation contains a loss.

fn is_end(&self) -> bool

Returns true if this evaluation is either a win or a loss.

Implementors