Initial commit

1 files changed, 46 insertions, 0 deletions

diff --git a/derive-macro/src/lib.rs b/derive-macro/src/lib.rs
new file mode 100644
index 0000000..9aa93f5
--- /dev/null
+++ b/derive-macro/src/lib.rs
@@ -0,0 +1,46 @@
+//! This crate provide the [`GenerateRandom`] derive macro
+//! that implements the trait of the same name from the `generate-random` crate.
+//! Refer to the documentation of that crate for more information.
+
+use syn::{DeriveInput, Data, Fields};
+
+mod handle_struct;
+mod handle_enum;
+
+#[proc_macro_derive(GenerateRandom, attributes(weight))]
+pub fn derive_generate_random(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
+    let input: DeriveInput = syn::parse(input).unwrap();
+    match input.data {
+        Data::Struct(ty) => handle_struct::generate(&input.ident, ty),
+        Data::Enum(ty) => handle_enum::generate(&input.ident, ty),
+        Data::Union(_) => panic!("Unions are not supported"),
+    }.into()
+}
+
+fn generate_fields(fields: Fields) -> proc_macro2::TokenStream {
+    use quote::quote;
+    match fields {
+        Fields::Named(fields) => {
+            let fields = fields.named.into_iter()
+                .map(|field| {
+                    let field = field.ident.unwrap();
+                    quote! {
+                        #field: generate_random::GenerateRandom::generate_random(rng),
+                    }
+                })
+                .collect::<proc_macro2::TokenStream>();
+            quote! { { #fields } }
+        }
+        Fields::Unnamed(fields) => {
+            let fields = fields.unnamed.into_iter()
+                .map(|_field| {
+                    quote! {
+                        generate_random::GenerateRandom::generate_random(rng),
+                    }
+                })
+                .collect::<proc_macro2::TokenStream>();
+            quote! { ( #fields ) }
+        }
+        Fields::Unit => quote! {},
+    }
+}