comparable_derive 0.5.5

A library for comparing data structures in Rust, oriented toward testing
Documentation 
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use proc_macro2::Span;

use crate::attrs::*;
use crate::definition::*;
use crate::outputs::*;

pub struct Inputs<'a> {
	pub attrs: Attributes,
	pub input: &'a syn::DeriveInput,
	pub visibility: syn::Visibility,
}

impl<'a> Inputs<'a> {
	pub fn from(input: &'a syn::DeriveInput) -> Self {
		let attrs = Attributes::from(&input.attrs);

		let visibility = if attrs.comparable_private {
			syn::Visibility::Inherited
		} else if attrs.comparable_public {
			syn::Visibility::Public(syn::VisPublic { pub_token: syn::token::Pub { span: Span::call_site() } })
		} else {
			input.vis.clone()
		};

		Inputs { attrs, input, visibility }
	}

	pub fn process_data(&self) -> Outputs {
		let is_unitary = match &self.input.data {
			syn::Data::Struct(st) => match &st.fields {
				syn::Fields::Unit => true,
				syn::Fields::Unnamed(unnamed) => unnamed.unnamed.is_empty(),
				syn::Fields::Named(named) => named.named.is_empty(),
			},
			syn::Data::Enum(en) => en.variants.is_empty(),
			syn::Data::Union(_st) => {
				panic!("Comparable derivation not available for unions");
			}
		};

		Outputs {
			desc: if self.attrs.no_description { None } else { Some(Definition::generate_desc_type(self)) },
			change: if is_unitary { None } else { Some(Definition::generate_change_type(self)) },
		}
	}
}