spire_enum_macros 0.3.0

Procedural macros to facilitate enum usage, such as when delegating implementations, extracting variant types, or creating enum tables.
Documentation 
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use kw::{mod_name as kw_mod_name, ty_name as kw_ty_name};
use syn::parse_quote;

mod kw {
	syn::custom_keyword!(ty_name);
	syn::custom_keyword!(mod_name);
}

pub mod discriminant_to_generic;
pub mod variant_type_to_generic;
pub mod variant_type_to_variant_type;

use super::*;

fn var_to_field_ident(ident: &Ident) -> Ident {
	let str = ident.to_string().to_case(Case::Snake);
	Ident::new_raw(&str, Span::call_site())
}

#[derive(Default)]
struct SaneTableMetas {
	syn_metas: Vec<SynMeta>,
	ty_name:   Optional<SettingTypeName>,
	mod_name:  Optional<SettingModName>,
}

#[derive(Parse, ToTokens)]
enum TableMeta {
	TypeName(SettingTypeName),
	ModuleName(SettingModName),
	Derive(SettingDerive),
	Attrs(SettingAttrs),
}

#[derive(Parse, ToTokens)]
struct SettingTypeName {
	kw: kw_ty_name,
	eq_token: Token![=],
	name: Ident,
}

#[derive(Parse, ToTokens)]
struct SettingModName {
	kw: kw_mod_name,
	eq_token: Token![=],
	name: Ident,
}

fn parse_table_metas(input: TokenStream1) -> Result<SaneTableMetas> {
	let input_attrs = syn::parse::<Punctuated<Meta<TableMeta>, Token![,]>>(input)?;

	let mut sane = SaneTableMetas::default();
	let (syn_metas, custom_attrs) = split_input_metas(input_attrs);
	sane.syn_metas = syn_metas;

	for meta in custom_attrs {
		match meta {
			TableMeta::TypeName(ty_name) => {
				assign_unique_or_panic!(sane.ty_name, ty_name);
			}
			TableMeta::ModuleName(mod_name) => {
				assign_unique_or_panic!(sane.mod_name, mod_name);
			}
			TableMeta::Derive(SettingDerive { kw, paths }) => {
				let syn_meta: SynMeta = parse_quote! { #kw #paths };
				sane.syn_metas.push(syn_meta);
			}
			TableMeta::Attrs(SettingAttrs { kw: _, attrs }) => {
				sane.syn_metas.extend(attrs.into_inner().into_iter())
			}
		}
	}

	Ok(sane)
}