[−][src]Crate proc_macro_roids
Traits and functions to make writing proc macros more ergonomic.
The roids name is chosen because, although these functions make it easy to perform certain operation, they may not necessarily be a good idea =D!
Examples
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Append additional
#[derive(..)]
s.This works for function-like or attribute proc macros.
ⓘThis example is not testedextern crate proc_macro; use proc_macro::TokenStream; use proc_macro_roids::DeriveInputDeriveExt; use quote::quote; use syn::{parse_macro_input, parse_quote, DeriveInput}; #[proc_macro_attribute] pub fn copy(_args: TokenStream, item: TokenStream) -> TokenStream { // Example input: // // #[derive(Debug)] // struct Struct; let mut ast = parse_macro_input!(item as DeriveInput); // Append the derives. let derives = parse_quote!(Clone, Copy); ast.append_derives(derives); // Example output: // // #[derive(Debug, Clone, Copy)] // struct Struct; TokenStream::from(quote! { #ast }) }
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Append named fields.
This works for structs with named fields or unit structs.
ⓘThis example is not testedextern crate proc_macro; use proc_macro::TokenStream; use proc_macro_roids::FieldsNamedAppend; use quote::quote; use syn::{parse_macro_input, parse_quote, DeriveInput, FieldsNamed}; /// Example usage: /// /// ```rust /// use macro_crate::append_cd; /// /// #[append_cd] /// struct StructNamed { a: u32, b: i32 } /// ``` #[proc_macro_attribute] pub fn append_cd(_args: TokenStream, item: TokenStream) -> TokenStream { // Example input: // // struct StructNamed { a: u32, b: i32 } let mut ast = parse_macro_input!(item as DeriveInput); // Append the fields. let fields_additional: FieldsNamed = parse_quote!({ c: i64, d: usize }); ast.append(fields_additional); // Example output: // // struct StructNamed { a: u32, b: i32, c: i64, d: usize } TokenStream::from(quote! { #ast }) }
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Append unnamed fields (tuples).
This works for structs with unnamed fields or unit structs.
ⓘThis example is not testedextern crate proc_macro; use proc_macro::TokenStream; use proc_macro_roids::FieldsUnnamedAppend; use quote::quote; use syn::{parse_macro_input, parse_quote, DeriveInput, FieldsUnnamed}; /// Example usage: /// /// ```rust /// use macro_crate::append_i64_usize; /// /// #[append_i64_usize] /// struct StructNamed { a: u32, b: i32 } /// ``` #[proc_macro_attribute] pub fn append_i64_usize(_args: TokenStream, item: TokenStream) -> TokenStream { // Example input: // // struct StructUnit; let mut ast = parse_macro_input!(item as DeriveInput); // Append the fields. let fields_additional: FieldsUnnamed = parse_quote!((i64, usize)); ast.append(fields_additional); // Example output: // // struct StructUnit(i64, usize); TokenStream::from(quote! { #ast }) }
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Get newtype inner
Field
.This works for structs with unnamed fields or unit structs.
ⓘThis example is not testedextern crate proc_macro; use proc_macro::TokenStream; use proc_macro_roids::DeriveInputNewtypeExt; use quote::quote; use syn::{parse_macro_input, parse_quote, DeriveInput, Type}; #[proc_macro_derive(Deref)] pub fn derive_deref(item: TokenStream) -> TokenStream { // Example input: // // #[derive(Deref)] // struct Newtype(u32); let mut ast = parse_macro_input!(item as DeriveInput); // Get the inner field. let inner_field = ast.inner_type(); // Implement `Deref` let type_name = &ast.ident; let token_stream_2 = quote! { #ast impl std::ops::Deref for #type_name { type Target = #inner_type; fn deref(&self) -> &Self::Target { &self.0 } } } TokenStream::from(token_stream_2) }
Traits
DeriveInputDeriveExt | Functions to make it ergonomic to work with |
DeriveInputNewtypeExt | Functions to make it ergonomic to work with newtype |
DeriveInputStructExt | Functions to make it ergonomic to work with |
FieldsNamedAppend | Indicates this type may have |
FieldsUnnamedAppend | Indicates this type may have |
Functions
ident_concat | Returns an |
meta_list_contains | Returns whether the |
nested_meta_to_ident | Returns the |