Device macro to generate stateful and publish variants of device specific poll inputs.

macros/node-poll-variants/src/lib.rs

@@ -0,0 +1,46 @@
+use proc_macro::TokenStream;
+use std::ops::Deref;
+use quote::quote;
+use syn::{parse_macro_input, DeriveInput, Data, Ident};
+
+// Struct name: Ads1256PollStateful, Ads1256PollPublish, Ads1256PollStatePub
+#[proc_macro_derive(PollVariants)]
+pub fn transducer_macro(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    let DeriveInput {
+        attrs,
+        vis,
+        ident,
+        generics,
+        data,
+    } = &input;
+    // Check that item the macro was used on is valid
+    match data {
+        Data::Struct(struct_data) => struct_data,
+        Data::Enum(_) => panic!("Stateful struct cannot be derived from an enum."),
+        Data::Union(_) => panic!("Stateful struct cannot be derived from a union.")
+    };
+    // Check if generics contains T
+
+    // If it does make sure it is T: Copy
+    // If it isn't Copy, panic
+
+    // If it doesn't contain T, add it for use in the type that will be generated
+
+    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
+
+    let stateful_name = format!("{ident}Stateful");
+    let stateful_ident = Ident::new(stateful_name.deref(), ident.span());
+
+    eprintln!("input: {input:#?}");
+    eprintln!("impl_generics: {impl_generics:#?}");
+
+    let expanded = quote! {
+        #vis struct #stateful_ident #generics {
+            pub poll: #ident #ty_generics,
+            pub state: physical::transducer::State<T>,
+        }
+    };
+
+    TokenStream::from(expanded)
+}