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https://gitlab.com/pulsechaincom/lighthouse-pulse.git
synced 2024-12-24 12:37:17 +00:00
Add extra level of comparisons to CompareFields
This commit is contained in:
Paul Hauner
parent
55ef75a44e
commit
e43d27f3e4
@ -1,3 +1,152 @@
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//! Provides field-by-field comparisons for structs and vecs.
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//!
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//! Returns comparisons as data, without making assumptions about the desired equality (e.g.,
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//! does not `panic!` on inequality).
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//!
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//! Note: `compare_fields_derive` requires `PartialEq` and `Debug` implementations.
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//!
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//! ## Example
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//!
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//! ```rust
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//! use compare_fields::{CompareFields, Comparison, FieldComparison};
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//! use compare_fields_derive::CompareFields;
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//!
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//! #[derive(PartialEq, Debug, CompareFields)]
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//! pub struct Bar {
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//! a: u64,
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//! b: u16,
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//! #[compare_fields(as_slice)]
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//! c: Vec<Foo>
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//! }
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//!
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//! #[derive(Clone, PartialEq, Debug, CompareFields)]
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//! pub struct Foo {
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//! d: String
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//! }
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//!
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//! let cat = Foo {d: "cat".to_string()};
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//! let dog = Foo {d: "dog".to_string()};
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//! let chicken = Foo {d: "chicken".to_string()};
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//!
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//! let mut bar_a = Bar {
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//! a: 42,
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//! b: 12,
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//! c: vec![ cat.clone(), dog.clone() ],
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//! };
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//!
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//! let mut bar_b = Bar {
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//! a: 42,
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//! b: 99,
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//! c: vec![ chicken.clone(), dog.clone()]
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//! };
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//!
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//! let cat_dog = Comparison::Child(FieldComparison {
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//! field_name: "d".to_string(),
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//! equal: false,
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//! a: "\"cat\"".to_string(),
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//! b: "\"dog\"".to_string(),
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//! });
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//! assert_eq!(cat.compare_fields(&dog), vec![cat_dog]);
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//!
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//! let bar_a_b = vec![
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//! Comparison::Child(FieldComparison {
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//! field_name: "a".to_string(),
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//! equal: true,
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//! a: "42".to_string(),
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//! b: "42".to_string(),
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//! }),
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//! Comparison::Child(FieldComparison {
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//! field_name: "b".to_string(),
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//! equal: false,
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//! a: "12".to_string(),
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//! b: "99".to_string(),
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//! }),
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//! Comparison::Parent{
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//! field_name: "c".to_string(),
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//! equal: false,
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//! children: vec![
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//! FieldComparison {
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//! field_name: "0".to_string(),
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//! equal: false,
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//! a: "Some(Foo { d: \"cat\" })".to_string(),
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//! b: "Some(Foo { d: \"chicken\" })".to_string(),
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//! },
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//! FieldComparison {
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//! field_name: "1".to_string(),
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//! equal: true,
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//! a: "Some(Foo { d: \"dog\" })".to_string(),
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//! b: "Some(Foo { d: \"dog\" })".to_string(),
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//! }
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//! ]
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//! }
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//! ];
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//! assert_eq!(bar_a.compare_fields(&bar_b), bar_a_b);
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//!
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//!
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//!
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//! // TODO:
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//! ```
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use std::fmt::Debug;
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#[derive(Debug, PartialEq, Clone)]
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pub enum Comparison {
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Child(FieldComparison),
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Parent {
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field_name: String,
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equal: bool,
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children: Vec<FieldComparison>,
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},
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}
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impl Comparison {
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pub fn child<T: Debug + PartialEq<T>>(field_name: String, a: &T, b: &T) -> Self {
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Comparison::Child(FieldComparison::new(field_name, a, b))
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}
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pub fn parent(field_name: String, equal: bool, children: Vec<FieldComparison>) -> Self {
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Comparison::Parent {
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field_name,
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equal,
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children,
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}
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}
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pub fn from_slice<T: Debug + PartialEq<T>>(field_name: String, a: &[T], b: &[T]) -> Self {
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let mut children = vec![];
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for i in 0..std::cmp::max(a.len(), b.len()) {
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children.push(FieldComparison::new(
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format!("{:}", i),
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&a.get(i),
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&b.get(i),
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));
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}
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Self::parent(field_name, a == b, children)
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}
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pub fn retain_children<F>(&mut self, f: F)
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where
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F: FnMut(&FieldComparison) -> bool,
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{
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match self {
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Comparison::Child(_) => (),
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Comparison::Parent { children, .. } => children.retain(f),
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}
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}
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pub fn equal(&self) -> bool {
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match self {
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Comparison::Child(fc) => fc.equal,
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Comparison::Parent { equal, .. } => *equal,
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}
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}
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pub fn not_equal(&self) -> bool {
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!self.equal()
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}
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}
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#[derive(Debug, PartialEq, Clone)]
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pub struct FieldComparison {
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pub field_name: String,
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@ -7,5 +156,24 @@ pub struct FieldComparison {
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}
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pub trait CompareFields {
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fn compare_fields(&self, b: &Self) -> Vec<FieldComparison>;
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fn compare_fields(&self, b: &Self) -> Vec<Comparison>;
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}
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impl FieldComparison {
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pub fn new<T: Debug + PartialEq<T>>(field_name: String, a: &T, b: &T) -> Self {
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Self {
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field_name,
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equal: a == b,
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a: format!("{:?}", a),
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b: format!("{:?}", b),
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}
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}
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pub fn equal(&self) -> bool {
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self.equal
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}
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pub fn not_equal(&self) -> bool {
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!self.equal()
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}
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}
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@ -1,46 +0,0 @@
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use compare_fields::{CompareFields, FieldComparison};
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use compare_fields_derive::CompareFields;
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#[derive(Clone, Debug, CompareFields)]
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pub struct Simple {
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a: u64,
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b: u16,
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c: Vec<u8>,
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}
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#[test]
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fn compare() {
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let foo = Simple {
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a: 42,
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b: 12,
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c: vec![1, 2],
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};
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let mut bar = foo.clone();
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let comparisons = foo.compare_fields(&bar);
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assert!(!comparisons.iter().any(|c| c.equal == false));
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assert_eq!(
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comparisons[0],
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FieldComparison {
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equal: true,
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field_name: "a".to_string(),
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a: "42".to_string(),
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b: "42".to_string(),
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}
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);
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bar.a = 30;
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assert_eq!(
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foo.compare_fields(&bar)[0],
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FieldComparison {
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equal: false,
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field_name: "a".to_string(),
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a: "42".to_string(),
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b: "30".to_string(),
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}
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);
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}
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@ -5,7 +5,16 @@ use proc_macro::TokenStream;
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use quote::quote;
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use syn::{parse_macro_input, DeriveInput};
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#[proc_macro_derive(CompareFields)]
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fn is_slice(field: &syn::Field) -> bool {
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for attr in &field.attrs {
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if attr.tts.to_string() == "( as_slice )" {
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return true;
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}
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}
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false
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}
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#[proc_macro_derive(CompareFields, attributes(compare_fields))]
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pub fn compare_fields_derive(input: TokenStream) -> TokenStream {
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let item = parse_macro_input!(input as DeriveInput);
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@ -17,37 +26,47 @@ pub fn compare_fields_derive(input: TokenStream) -> TokenStream {
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_ => panic!("compare_fields_derive only supports structs."),
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};
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let mut idents_a = vec![];
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let mut field_names = vec![];
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let mut quotes = vec![];
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for field in struct_data.fields.iter() {
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let ident = match &field.ident {
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let ident_a = match &field.ident {
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Some(ref ident) => ident,
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_ => panic!("compare_fields_derive only supports named struct fields."),
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};
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field_names.push(format!("{:}", ident));
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idents_a.push(ident);
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}
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let field_name = format!("{:}", ident_a);
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let ident_b = ident_a.clone();
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let idents_b = idents_a.clone();
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let idents_c = idents_a.clone();
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let idents_d = idents_a.clone();
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let quote = if is_slice(field) {
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quote! {
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comparisons.push(compare_fields::Comparison::from_slice(
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#field_name.to_string(),
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&self.#ident_a,
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&b.#ident_b)
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);
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}
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} else {
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quote! {
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comparisons.push(
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compare_fields::Comparison::child(
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#field_name.to_string(),
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&self.#ident_a,
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&b.#ident_b
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)
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);
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}
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};
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quotes.push(quote);
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}
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let output = quote! {
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impl #impl_generics compare_fields::CompareFields for #name #ty_generics #where_clause {
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fn compare_fields(&self, b: &Self) -> Vec<compare_fields::FieldComparison> {
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fn compare_fields(&self, b: &Self) -> Vec<compare_fields::Comparison> {
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let mut comparisons = vec![];
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#(
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comparisons.push(
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compare_fields::FieldComparison {
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equal: self.#idents_a == b.#idents_b,
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field_name: #field_names.to_string(),
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a: format!("{:?}", self.#idents_c),
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b: format!("{:?}", b.#idents_d),
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}
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);
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#quotes
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)*
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comparisons
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