Restructure project directories (#333)

`/client/web` -> `/frontend`
`/client/cli` -> *delete for now*
`/client/native` -> *delete for now*
`/core/editor` -> `/editor`
`/core/document` -> `/graphene`
`/core/renderer` -> `/charcoal`
`/core/proc-macro` -> `/proc-macros` *(now plural)*

proc-macros/src/as_message.rs

@@ -0,0 +1,55 @@
+use proc_macro2::{Span, TokenStream};
+use syn::{Data, DeriveInput};
+
+pub fn derive_as_message_impl(input_item: TokenStream) -> syn::Result<TokenStream> {
+	let input = syn::parse2::<DeriveInput>(input_item).unwrap();
+
+	let data = match input.data {
+		Data::Enum(data) => data,
+		_ => return Err(syn::Error::new(Span::call_site(), "Tried to derive AsMessage for non-enum")),
+	};
+
+	let input_type = input.ident;
+
+	let (globs, names) = data
+		.variants
+		.iter()
+		.map(|var| {
+			let var_name = &var.ident;
+			let var_name_s = var.ident.to_string();
+			if var.attrs.iter().any(|a| a.path.is_ident("child")) {
+				(
+					quote::quote! {
+						#input_type::#var_name(child)
+					},
+					quote::quote! {
+						format!("{}.{}", #var_name_s, child.local_name())
+					},
+				)
+			} else {
+				(
+					quote::quote! {
+						#input_type::#var_name { .. }
+					},
+					quote::quote! {
+						#var_name_s.to_string()
+					},
+				)
+			}
+		})
+		.unzip::<_, _, Vec<_>, Vec<_>>();
+
+	let res = quote::quote! {
+		impl AsMessage for #input_type {
+			fn local_name(self) -> String {
+				match self {
+					#(
+						#globs => #names
+					),*
+				}
+			}
+		}
+	};
+
+	Ok(res)
+}