| // Copyright (c) 2018 The predicates-rs Project Developers. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Name predicate expressions. |
| |
| use std::fmt; |
| use std::marker::PhantomData; |
| |
| use crate::reflection; |
| use crate::Predicate; |
| |
| /// Augment an existing predicate with a name. |
| /// |
| /// This is created by the `PredicateNameExt::name` function. |
| #[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| pub struct NamePredicate<M, Item> |
| where |
| M: Predicate<Item>, |
| Item: ?Sized, |
| { |
| inner: M, |
| name: &'static str, |
| _phantom: PhantomData<Item>, |
| } |
| |
| unsafe impl<M, Item> Send for NamePredicate<M, Item> |
| where |
| M: Predicate<Item> + Send, |
| Item: ?Sized, |
| { |
| } |
| |
| unsafe impl<M, Item> Sync for NamePredicate<M, Item> |
| where |
| M: Predicate<Item> + Sync, |
| Item: ?Sized, |
| { |
| } |
| |
| impl<M, Item> Predicate<Item> for NamePredicate<M, Item> |
| where |
| M: Predicate<Item>, |
| Item: ?Sized, |
| { |
| fn eval(&self, item: &Item) -> bool { |
| self.inner.eval(item) |
| } |
| |
| fn find_case<'a>(&'a self, expected: bool, variable: &Item) -> Option<reflection::Case<'a>> { |
| self.inner |
| .find_case(expected, variable) |
| .map(|child_case| reflection::Case::new(Some(self), expected).add_child(child_case)) |
| } |
| } |
| |
| impl<M, Item> reflection::PredicateReflection for NamePredicate<M, Item> |
| where |
| M: Predicate<Item>, |
| Item: ?Sized, |
| { |
| fn children<'a>(&'a self) -> Box<dyn Iterator<Item = reflection::Child<'a>> + 'a> { |
| let params = vec![reflection::Child::new(self.name, &self.inner)]; |
| Box::new(params.into_iter()) |
| } |
| } |
| |
| impl<M, Item> fmt::Display for NamePredicate<M, Item> |
| where |
| M: Predicate<Item>, |
| Item: ?Sized, |
| { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| let palette = crate::Palette::new(f.alternate()); |
| write!(f, "{}", palette.description(self.name)) |
| } |
| } |
| |
| /// `Predicate` extension that adds naming predicate expressions. |
| pub trait PredicateNameExt<Item: ?Sized> |
| where |
| Self: Predicate<Item>, |
| { |
| /// Name a predicate expression. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use predicates::prelude::*; |
| /// |
| /// let predicate_fn = predicate::str::is_empty().not().name("non-empty"); |
| /// println!("{}", predicate_fn); |
| /// ``` |
| fn name(self, name: &'static str) -> NamePredicate<Self, Item> |
| where |
| Self: Sized, |
| { |
| NamePredicate { |
| inner: self, |
| name, |
| _phantom: PhantomData, |
| } |
| } |
| } |
| |
| impl<P, Item> PredicateNameExt<Item> for P |
| where |
| P: Predicate<Item>, |
| Item: ?Sized, |
| { |
| } |