Struct Config

pub struct Config<T: Clone + Eq + Hash> {
    pub table: Table<T>,
    pub inversed: bool,
    pub repetitive: bool,
}

Configuration required by Picker. All members are public and are supposed to be modified by the user.

Fields

table: Table<T>

Table of choices and weights which are proportional to the probabilities on repetitive mode or single-item mode.

inversed: bool

Do multiplicative inversion for each value in the table.

repetitive: bool

Allow the same item to be picked for multiple times in the result.

Implementations

impl<T: Clone + Eq + Hash> Config<T>

pub fn calc_probabilities(&self, pick_amount: usize) -> Result<Table<T>, Error>

Calculates probabilities of existences of table items in each picking result of length pick_amount. In non-repetitive mode, the multi-thread tree algorithm may be used.

TODO: figure out why its single-thread performance is 10.3% slower than the previous C++ version, and unsafe operations can’t make it faster.

impl<T: Clone + Eq + Hash> Config<T>

pub fn new() -> Self

Returns an invalid configuration with an empty table. Please add items into the table before using it to construct Picker.

pub fn check(&self) -> Result<(), Error>

Checks whether or not the table can be used by Picker.

pub fn is_fair(&self) -> bool

Returns true if all items have equal (and valid) weight values.

impl Config<String>

pub fn append_str(&mut self, str_items: &str)

Appends, modifies or deletes items in the table according to the configuration input string.

let mut conf: random_picker::Config<String> = "
repetitive = true
inversed = false
[items]
oxygen = 47
sillicon = 28
aluminium=8; iron=5; magnesium=4;
calcium=2: potassium=2: sodium=2:
others = 2; nonexistium = 31
   aluminium = 9; delete nonexistium
".parse().unwrap();
assert_eq!(conf.table.len(), 9);
assert_eq!(conf.repetitive, true);
assert_eq!(conf.inversed, false);
assert_eq!(conf.table.get("aluminium"), Some(&9.));

conf.append_str("\
power_inversed
# invalid: repetitive = 0
repetitive = 0
delete others
");
assert_eq!(conf.repetitive, true);
assert_eq!(conf.inversed, true);

conf.append_str("inversed = false");
assert_eq!(conf.inversed, false);

Trait Implementations

impl<T: Clone + Clone + Eq + Hash> Clone for Config<T>

fn clone(&self) -> Config<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug + Clone + Eq + Hash> Debug for Config<T>

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

Formats the value using the given formatter.

impl<T: Clone + Eq + Hash> Default for Config<T>

fn default() -> Self

Returns the “default value” for a type.

impl Display for Config<String>

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

Formats the value using the given formatter.

impl FromStr for Config<String>

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl<T: PartialEq + Clone + Eq + Hash> PartialEq for Config<T>

fn eq(&self, other: &Config<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Clone + Eq + Hash> StructuralPartialEq for Config<T>