use proc_macro2::{Ident, Span, TokenStream};
use quote::quote;
use syn::{
parse::{Parse, ParseStream},
punctuated::Punctuated,
Expr, Token,
};
pub struct DoMenuItemInput {
resources_table: Ident,
rid: Ident,
kind: Ident,
var: Ident,
expr: Expr,
kinds: Vec<NegatedIdent>,
}
#[derive(Clone)]
struct NegatedIdent {
negated: bool,
ident: Ident,
}
impl NegatedIdent {
fn new(ident: &str) -> Self {
Self {
negated: false,
ident: Ident::new(ident, Span::call_site()),
}
}
fn is_negated(&self) -> bool {
self.negated
}
}
impl Parse for NegatedIdent {
fn parse(input: ParseStream) -> syn::Result<Self> {
let negated_token = input.parse::<Token![!]>();
let ident: Ident = input.parse()?;
Ok(NegatedIdent {
negated: negated_token.is_ok(),
ident,
})
}
}
impl Parse for DoMenuItemInput {
fn parse(input: ParseStream) -> syn::Result<Self> {
let resources_table: Ident = input.parse()?;
let _: Token![,] = input.parse()?;
let rid: Ident = input.parse()?;
let _: Token![,] = input.parse()?;
let kind: Ident = input.parse()?;
let _: Token![,] = input.parse()?;
let _: Token![|] = input.parse()?;
let var: Ident = input.parse()?;
let _: Token![|] = input.parse()?;
let expr: Expr = input.parse()?;
let _: syn::Result<Token![,]> = input.parse();
let kinds = Punctuated::<NegatedIdent, Token![|]>::parse_terminated(input)?;
Ok(Self {
resources_table,
rid,
kind,
var,
expr,
kinds: kinds.into_iter().collect(),
})
}
}
pub fn do_menu_item(input: DoMenuItemInput) -> TokenStream {
let DoMenuItemInput {
rid,
resources_table,
kind,
expr,
var,
mut kinds,
} = input;
let defaults = vec![
NegatedIdent::new("Submenu"),
NegatedIdent::new("MenuItem"),
NegatedIdent::new("Predefined"),
NegatedIdent::new("Check"),
NegatedIdent::new("Icon"),
];
if kinds.is_empty() {
kinds.extend(defaults.clone());
}
let has_negated = kinds.iter().any(|n| n.is_negated());
if has_negated {
kinds.extend(defaults);
kinds.sort_by(|a, b| a.ident.cmp(&b.ident));
kinds.dedup_by(|a, b| a.ident == b.ident);
}
let (kinds, types): (Vec<Ident>, Vec<Ident>) = kinds
.into_iter()
.filter_map(|nident| {
if nident.is_negated() {
None
} else {
match nident.ident {
i if i == "MenuItem" => Some((i, Ident::new("MenuItem", Span::call_site()))),
i if i == "Submenu" => Some((i, Ident::new("Submenu", Span::call_site()))),
i if i == "Predefined" => Some((i, Ident::new("PredefinedMenuItem", Span::call_site()))),
i if i == "Check" => Some((i, Ident::new("CheckMenuItem", Span::call_site()))),
i if i == "Icon" => Some((i, Ident::new("IconMenuItem", Span::call_site()))),
_ => None,
}
}
})
.unzip();
quote! {
match #kind {
#(
ItemKind::#kinds => {
let #var = #resources_table.get::<#types<R>>(#rid)?;
#expr
}
)*
_ => unreachable!(),
}
}
}