Use proc macros to expand the number of traits

2 files changed, 134 insertions, 7 deletions

diff --git a/varihappy-macros/Cargo.toml b/varihappy-macros/Cargo.toml
index 968ce85..3999ad5 100644
--- a/varihappy-macros/Cargo.toml
+++ b/varihappy-macros/Cargo.toml
@@ -7,4 +7,6 @@ edition = "2024"
 proc-macro = true
 
 [dependencies]
-proc_macros = "0.1.0"
+proc-macro2 = "1"
+syn = "2"
+quote = "1"
diff --git a/varihappy-macros/src/lib.rs b/varihappy-macros/src/lib.rs
index 561962c..522d333 100644
--- a/varihappy-macros/src/lib.rs
+++ b/varihappy-macros/src/lib.rs
@@ -1,15 +1,140 @@
-use proc_macro::{Ident, Span, TokenStream, TokenTree};
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use proc_macro2::{Ident, Literal, Span};
+use quote::quote;
+use syn::{Field, LitInt};
 
 #[proc_macro]
 pub fn concat_idents(input: TokenStream) -> TokenStream {
 	let mut buffer = String::new();
 	for token in input {
-		if let TokenTree::Ident(identifier) = token {
-			buffer.push_str(&identifier.to_string());
-		}
+		buffer.push_str(&token.to_string());
 	}
 
-	let mut stream = TokenStream::new();
+	let mut stream = proc_macro2::TokenStream::new();
 	stream.extend([Ident::new(&buffer, Span::call_site())]);
-	stream
+	stream.into()
+}
+
+#[proc_macro]
+pub fn number_to_generic(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let identifier = Ident::new(
+		match number {
+			0 => "A",
+			1 => "B",
+			2 => "C",
+			3 => "D",
+			4 => "E",
+			5 => "F",
+			6 => "G",
+			7 => "H",
+			8 => "I",
+			9 => "J",
+			10 => "K",
+			11 => "L",
+			12 => "M",
+			13 => "N",
+			14 => "O",
+			15 => "P",
+			16 => "Q",
+			17 => "R",
+			18 => "S",
+			19 => "T",
+			20 => "U",
+			21 => "V",
+			22 => "W",
+			23 => "X",
+			24 => "Y",
+			25 => "Z",
+			_ => panic!("Expected a number less than 26"),
+		},
+		Span::call_site(),
+	);
+
+	quote! { #identifier }.into()
+}
+
+#[proc_macro]
+pub fn tuple_type_len(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = 0..number;
+	quote! { (#(::varihappy_macros::number_to_generic!(#num),)*) }.into()
+}
+
+#[proc_macro]
+pub fn tuple_type_ref(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = 0..number;
+	quote! { (#(&'a ::varihappy_macros::number_to_generic!(#num),)*) }.into()
+}
+
+#[proc_macro]
+pub fn tuple_type_mut(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = 0..number;
+	quote! { (#(&'a mut ::varihappy_macros::number_to_generic!(#num),)*) }.into()
+}
+
+#[proc_macro]
+pub fn reverse_tuple_type(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = (0..number).rev();
+	quote! { (#(::varihappy_macros::number_to_generic!(#num),)*) }.into()
+}
+
+#[proc_macro]
+pub fn tuple_type_len_rest(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = 1..number;
+	quote! { (#(::varihappy_macros::number_to_generic!(#num),)*) }.into()
+}
+
+#[proc_macro]
+pub fn tuple_expr_ref(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = (0..number).map(Literal::u128_unsuffixed);
+	quote! { (#(&self.#num,)*) }.into()
+}
+
+#[proc_macro]
+pub fn tuple_expr_mut(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = (0..number).map(Literal::u128_unsuffixed);
+	quote! { (#(&mut self.#num,)*) }.into()
+}
+
+#[proc_macro]
+pub fn reverse_expr_type(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = (0..number).rev().map(Literal::u128_unsuffixed);
+	quote! { (#(self.#num,)*) }.into()
+}
+
+#[proc_macro]
+pub fn tuple_expr_len_rest(input: TokenStream) -> TokenStream {
+	let number = syn::parse_macro_input!(input as LitInt);
+	let number: u128 = number.base10_parse().expect("a number 0..=u128::MAX");
+
+	let num = (1..number).map(Literal::u128_unsuffixed);
+	quote! { (#(self.#num,)*) }.into()
 }