Struct predicates::function::FnPredicate

pub struct FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: ?Sized,  { /* fields omitted */ }

Predicate that wraps a function over a reference that returns a bool. This type is returned by the predicate::function function.

Methods

impl<F, T> FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: ?Sized, 

pub fn fn_name(self, name: &'static str) -> Self

Provide a descriptive name for this function.

Examples

use predicates::prelude::*;

struct Example {
    string: String,
    number: i32,
}

let string_check = predicate::function(|x: &Example| x.string == "hello")
    .fn_name("is_hello");
println!("predicate: {}", string_check);

Trait Implementations

impl<F: Eq, T> Eq for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: Eq + ?Sized, 

impl<F: Copy, T> Copy for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: Copy + ?Sized, 

impl<F: PartialEq, T> PartialEq<FnPredicate<F, T>> for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: PartialEq + ?Sized, 

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

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

fn ne(&self, other: &FnPredicate<F, T>) -> bool

This method tests for !=.

impl<F: Clone, T> Clone for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: Clone + ?Sized, 

fn clone(&self) -> FnPredicate<F, T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<F, T> Display for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: ?Sized, 

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

Formats the value using the given formatter.

impl<F: Debug, T> Debug for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: Debug + ?Sized, 

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

Formats the value using the given formatter.

impl<F, T> Predicate<T> for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: ?Sized, 

fn eval(&self, variable: &T) -> bool

Execute this Predicate against variable, returning the resulting boolean.

fn find_case<'a>(&'a self, expected: bool, variable: &T) -> Option<Case<'a>>

Find a case that proves this predicate as expected when run against variable.

impl<F, T> PredicateReflection for FnPredicate<F, T> where
    F: Fn(&T) -> bool,
    T: ?Sized, 

fn parameters(&'a self) -> Box<dyn Iterator<Item = Parameter<'a>> + 'a>

Parameters of the current Predicate.

fn children(&'a self) -> Box<dyn Iterator<Item = Child<'a>> + 'a>

Nested Predicates of the current Predicate.