From 4f04d1e6f02113ad0f539b723333f8f1f5734f13 Mon Sep 17 00:00:00 2001 From: Nadrieril Date: Sat, 4 May 2019 12:40:48 +0200 Subject: Rename dhall_generator to dhall_proc_macros --- dhall_generator/src/derive.rs | 179 ------------------------------------------ 1 file changed, 179 deletions(-) delete mode 100644 dhall_generator/src/derive.rs (limited to 'dhall_generator/src/derive.rs') diff --git a/dhall_generator/src/derive.rs b/dhall_generator/src/derive.rs deleted file mode 100644 index bcefb17..0000000 --- a/dhall_generator/src/derive.rs +++ /dev/null @@ -1,179 +0,0 @@ -extern crate proc_macro; -// use dhall_syntax::*; -use proc_macro::TokenStream; -use quote::{quote, quote_spanned}; -use syn::spanned::Spanned; -use syn::Error; -use syn::{parse_quote, DeriveInput}; - -pub fn derive_simple_static_type(input: TokenStream) -> TokenStream { - TokenStream::from(match derive_simple_static_type_inner(input) { - Ok(tokens) => tokens, - Err(err) => err.to_compile_error(), - }) -} - -fn get_simple_static_type(ty: T) -> proc_macro2::TokenStream -where - T: quote::ToTokens, -{ - quote!( - <#ty as ::dhall::de::SimpleStaticType>::get_simple_static_type() - ) -} - -fn derive_for_struct( - data: &syn::DataStruct, - constraints: &mut Vec, -) -> Result { - let fields = match &data.fields { - syn::Fields::Named(fields) => fields - .named - .iter() - .map(|f| { - let name = f.ident.as_ref().unwrap().to_string(); - let ty = &f.ty; - (name, ty) - }) - .collect(), - syn::Fields::Unnamed(fields) => fields - .unnamed - .iter() - .enumerate() - .map(|(i, f)| { - let name = format!("_{}", i + 1); - let ty = &f.ty; - (name, ty) - }) - .collect(), - syn::Fields::Unit => vec![], - }; - let fields = fields - .into_iter() - .map(|(name, ty)| { - let name = dhall_syntax::Label::from(name); - constraints.push(ty.clone()); - let ty = get_simple_static_type(ty); - (name, quote!(#ty.into())) - }) - .collect(); - let record = - crate::quote::quote_exprf(dhall_syntax::ExprF::RecordType(fields)); - Ok(quote! { dhall_syntax::rc(#record) }) -} - -fn derive_for_enum( - data: &syn::DataEnum, - constraints: &mut Vec, -) -> Result { - let variants = data - .variants - .iter() - .map(|v| { - let name = dhall_syntax::Label::from(v.ident.to_string()); - match &v.fields { - syn::Fields::Unit => Ok((name, None)), - syn::Fields::Unnamed(fields) if fields.unnamed.is_empty() => { - Ok((name, None)) - } - syn::Fields::Unnamed(fields) if fields.unnamed.len() == 1 => { - let ty = &fields.unnamed.iter().next().unwrap().ty; - constraints.push(ty.clone()); - let ty = get_simple_static_type(ty); - Ok((name, Some(quote!(#ty.into())))) - } - syn::Fields::Unnamed(_) => Err(Error::new( - v.span(), - "Variants with more than one field are not supported", - )), - syn::Fields::Named(_) => Err(Error::new( - v.span(), - "Named variants are not supported", - )), - } - }) - .collect::>()?; - - let union = - crate::quote::quote_exprf(dhall_syntax::ExprF::UnionType(variants)); - Ok(quote! { dhall_syntax::rc(#union) }) -} - -pub fn derive_simple_static_type_inner( - input: TokenStream, -) -> Result { - let input: DeriveInput = syn::parse_macro_input::parse(input)?; - - // List of types that must impl Type - let mut constraints = vec![]; - - let get_type = match &input.data { - syn::Data::Struct(data) => derive_for_struct(data, &mut constraints)?, - syn::Data::Enum(data) if data.variants.is_empty() => { - return Err(Error::new( - input.span(), - "Empty enums are not supported", - )) - } - syn::Data::Enum(data) => derive_for_enum(data, &mut constraints)?, - syn::Data::Union(x) => { - return Err(Error::new( - x.union_token.span(), - "Unions are not supported", - )) - } - }; - - let mut generics = input.generics.clone(); - generics.make_where_clause(); - let (impl_generics, ty_generics, orig_where_clause) = - generics.split_for_impl(); - let orig_where_clause = orig_where_clause.unwrap(); - - // Hygienic errors - let assertions = constraints.iter().enumerate().map(|(i, ty)| { - // Ensure that ty: Type, with an appropriate span - let assert_name = - syn::Ident::new(&format!("_AssertType{}", i), ty.span()); - let mut local_where_clause = orig_where_clause.clone(); - local_where_clause - .predicates - .push(parse_quote!(#ty: ::dhall::de::SimpleStaticType)); - let phantoms = generics.params.iter().map(|param| match param { - syn::GenericParam::Type(syn::TypeParam { ident, .. }) => { - quote!(#ident) - } - syn::GenericParam::Lifetime(syn::LifetimeDef { - lifetime, .. - }) => quote!(&#lifetime ()), - _ => unimplemented!(), - }); - quote_spanned! {ty.span()=> - struct #assert_name #impl_generics #local_where_clause { - _phantom: std::marker::PhantomData<(#(#phantoms),*)> - }; - } - }); - - // Ensure that all the fields have a Type impl - let mut where_clause = orig_where_clause.clone(); - for ty in constraints.iter() { - where_clause - .predicates - .push(parse_quote!(#ty: ::dhall::de::SimpleStaticType)); - } - - let ident = &input.ident; - let tokens = quote! { - impl #impl_generics ::dhall::de::SimpleStaticType - for #ident #ty_generics - #where_clause { - fn get_simple_static_type<'get_simple_static_type>() -> - ::dhall::expr::SimpleType<'get_simple_static_type> { - #(#assertions)* - ::dhall::expr::SimpleType::from(#get_type) - } - } - }; - Ok(tokens) -} -- cgit v1.2.3