feat: disallow custom discriminants

Pscheidl · Jan 15, 2023 · 5925a72 · 5925a72
1 parent 3eed022
commit 5925a72
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Showing 6 changed files with 22 additions and 58 deletions.
diff --git a/enum-collections-macros/Cargo.toml b/enum-collections-macros/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "enum-collections-macros"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 
 description = "Macros to make EnumCollections easy to use"
@@ -18,3 +18,4 @@ proc-macro = true
 
 [dependencies]
 syn = "1.0"
+quote = "1.0"
diff --git a/enum-collections-macros/src/lib.rs b/enum-collections-macros/src/lib.rs
@@ -1,69 +1,32 @@
 use proc_macro::TokenStream;
-use syn::{
-    parse_macro_input, DeriveInput,
-    __private::{quote::quote, ToTokens},
-};
+use quote::{quote, quote_spanned};
+use syn::{parse_macro_input, spanned::Spanned, DeriveInput};
 
 /// Creates `enum_map::Enumerated` implementation for the underlying Enum.
 /// Also derives Copy and Clone.
-#[proc_macro_attribute]
-#[deprecated(since = "0.4.0", note = "Use #[derive(Enumerated)] instead")]
-pub fn enum_collections(_args: TokenStream, input: TokenStream) -> TokenStream {
+#[proc_macro_derive(Enumerated)]
+pub fn derive_enum_collections(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
     let generics = &input.generics;
     let name = &input.ident;
-    let enum_count: usize = match &input.data {
-        syn::Data::Enum(en) => en.variants.iter().count(),
-        syn::Data::Struct(_) | syn::Data::Union(_) => {
-            return quote! {
-                #input
-                compile_error!("The `enummap` macro only supports enums.");
+    let syn::Data::Enum(en) = input.data else {
+            return quote_spanned! {
+                input.span() => compile_error!("The `Enumerated` macro only supports enums.");
             }
-            .to_token_stream()
-            .to_token_stream()
             .into();
-        }
-    };
-
-    let output = quote! {
-        #input
-
-        impl #generics Enumerated for #name #generics {
-
-            fn position(self) -> usize {
-                self as usize
-            }
-
-            const fn len() -> usize{
-                #enum_count
-            }
-
-        }
     };
-    TokenStream::from(output.to_token_stream())
-}
+    let enum_count = en.variants.iter().count();
 
-/// Creates `enum_map::Enumerated` implementation for the underlying Enum.
-/// Also derives Copy and Clone.
-#[proc_macro_derive(Enumerated)]
-pub fn derive_enum_collections(input: TokenStream) -> TokenStream {
-    let input = parse_macro_input!(input as DeriveInput);
-    let generics = &input.generics;
-    let name = &input.ident;
-    let enum_count: usize = match &input.data {
-        syn::Data::Enum(en) => en.variants.iter().count(),
-        syn::Data::Struct(_) | syn::Data::Union(_) => {
-            return quote! {
-                #input
-                compile_error!("The `enummap` macro only supports enums.");
+    for variant in en.variants {
+        if let Some((_, discriminant)) = variant.discriminant {
+            return quote_spanned! {
+                discriminant.span() => compile_error!("`Enumerated` doesn't support discriminants");
             }
-            .to_token_stream()
-            .to_token_stream()
             .into();
         }
-    };
+    }
 
-    let output = quote! {
+    quote! {
         impl #generics Enumerated for #name #generics {
 
             fn position(self) -> usize {
@@ -75,6 +38,6 @@ pub fn derive_enum_collections(input: TokenStream) -> TokenStream {
             }
 
         }
-    };
-    TokenStream::from(output.to_token_stream())
+    }
+    .into()
 }
diff --git a/enum-collections/Cargo.toml b/enum-collections/Cargo.toml
@@ -13,7 +13,7 @@ categories = ["data-structures"]
 documentation = "https://docs.rs/enum-collections"
 
 [dependencies]
-enum-collections-macros = "0.2.0"
+enum-collections-macros = "0.4.0"
 
 [dev-dependencies]
 criterion = "0.4.0"

diff --git a/enum-collections/src/enummap/mod.rs b/enum-collections/src/enummap/mod.rs
@@ -13,7 +13,7 @@ use crate::Enumerated;
 /// Using `get` and `insert` functions.
 ///
 /// ```
-/// use enum_collections::{enum_collections, EnumMap, Enumerated};
+/// use enum_collections::{EnumMap, Enumerated};
 /// #[derive(Enumerated)]
 /// enum Letter {
 ///     A,
@@ -111,6 +111,7 @@ mod tests {
         A,
         B,
     }
+
     #[test]
     fn new_all_none() {
         let enum_map = EnumMap::<Letter, i32>::new();

diff --git a/enum-collections/src/enumtable/mod.rs b/enum-collections/src/enumtable/mod.rs
@@ -21,7 +21,7 @@ use crate::Enumerated;
 ///
 /// Using get and insert functions.
 /// ```
-/// use enum_collections::{enum_collections, EnumTable, Enumerated};
+/// use enum_collections::{EnumTable, Enumerated};
 /// #[derive(Enumerated)]
 /// enum Letter {
 ///     A,

diff --git a/enum-collections/src/lib.rs b/enum-collections/src/lib.rs
@@ -5,7 +5,6 @@ mod enumtable;
 pub use crate::enumerated::Enumerated;
 pub use crate::enummap::EnumMap;
 pub use crate::enumtable::EnumTable;
-pub use enum_collections_macros::enum_collections;
 pub use enum_collections_macros::Enumerated;
 
 #[cfg(test)]