relax explicit lifetime requirement

Author: sarah

README.md

@@ -64,7 +64,6 @@ Only available with the `macro` feature.
 
 Requires the first non-lifetime generic parameter, as well as the function's
 first input parameter to be the SIMD type.
-Also currently requires that all the lifetimes be explicitly specified.
 
 ```rust
 #[pulp::with_simd(sum = pulp::Arch::new())]

pulp-macro/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pulp-macro"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 authors = ["sarah <>"]
 description = "Safe generic simd"

pulp-macro/src/lib.rs

@@ -1,8 +1,11 @@
-use proc_macro2::TokenStream;
+use proc_macro2::{Ident, Span, TokenStream};
 use quote::quote;
 use syn::punctuated::Punctuated;
-use syn::token::{Brace, Colon};
-use syn::{FieldsNamed, FnArg, ItemFn};
+use syn::token::{Colon, PathSep};
+use syn::{
+    ConstParam, FnArg, GenericParam, ItemFn, LifetimeParam, Pat, PatIdent, PatType, Path,
+    PathSegment, Type, TypeParam, TypePath,
+};
 
 #[proc_macro_attribute]
 pub fn with_simd(
@@ -40,20 +43,13 @@ pub fn with_simd(
         block,
     } = item.clone();
 
-    let mut struct_generics = Punctuated::new();
-    let mut struct_generics_lifetimes = Vec::new();
-    let mut struct_generics_names = Vec::new();
+    let mut struct_generics = Vec::new();
     let mut struct_field_names = Vec::new();
-    let mut struct_fields = FieldsNamed {
-        brace_token: Brace {
-            span: sig.paren_token.span,
-        },
-        named: Punctuated::new(),
-    };
+    let mut struct_field_types = Vec::new();
 
     let mut first_non_lifetime = usize::MAX;
     for (idx, param) in sig.generics.params.clone().into_pairs().enumerate() {
-        let (param, comma) = param.into_tuple();
+        let (param, _) = param.into_tuple();
         match &param {
             syn::GenericParam::Lifetime(_) => {}
             _ => {
@@ -63,17 +59,7 @@ pub fn with_simd(
                 }
             }
         }
-        match &param {
-            syn::GenericParam::Type(ty) => struct_generics_names.push(ty.ident.clone()),
-            syn::GenericParam::Lifetime(lt) => struct_generics_lifetimes.push(lt.lifetime.clone()),
-            syn::GenericParam::Const(const_) => struct_generics_names.push(const_.ident.clone()),
-        };
-        struct_generics.push_value(param);
-        if let Some(comma) = comma {
-            struct_generics.push_punct(comma);
-        }
     }
-
     let mut new_fn_sig = sig.clone();
     new_fn_sig.generics.params = new_fn_sig
         .generics
@@ -83,49 +69,61 @@ pub fn with_simd(
         .filter(|(idx, _)| *idx != first_non_lifetime)
         .map(|(_, arg)| arg)
         .collect();
-    new_fn_sig.inputs = new_fn_sig.inputs.into_iter().skip(1).collect();
+    new_fn_sig.inputs = new_fn_sig
+        .inputs
+        .into_iter()
+        .skip(1)
+        .enumerate()
+        .map(|(idx, arg)| {
+            FnArg::Typed(PatType {
+                attrs: Vec::new(),
+                pat: Box::new(Pat::Ident(PatIdent {
+                    attrs: Vec::new(),
+                    by_ref: None,
+                    mutability: None,
+                    ident: Ident::new(&format!("__{idx}"), Span::call_site()),
+                    subpat: None,
+                })),
+                colon_token: Colon {
+                    spans: [Span::call_site()],
+                },
+                ty: match arg {
+                    FnArg::Typed(ty) => ty.ty,
+                    FnArg::Receiver(_) => panic!(),
+                },
+            })
+        })
+        .collect();
     new_fn_sig.ident = name.clone();
+    let mut param_ty = Vec::new();
 
-    for param in sig.inputs.clone().into_pairs().skip(1) {
-        let (param, comma) = param.into_tuple();
+    for (idx, param) in new_fn_sig.inputs.clone().into_pairs().enumerate() {
+        let (param, _) = param.into_tuple();
         let FnArg::Typed(param) = param.clone() else {
-            return quote! {
-                ::core::compile_error!(::core::concat!(
-                    "pulp::with_simd only accepts free functions"
-                ));
-                #item
-            }
-            .into();
+            panic!();
         };
-
         let name = *param.pat;
         let syn::Pat::Ident(name) = name else {
-            return quote! {
-                ::core::compile_error!(::core::concat!(
-                        "pulp::with_simd requires function parameters to be idents"
-                        ));
-                #item
-            }
-            .into();
+            panic!();
         };
 
+        let anon_ty = Ident::new(&format!("__T{idx}"), Span::call_site());
+
         struct_field_names.push(name.ident.clone());
-        let field = syn::Field {
-            attrs: param.attrs,
-            vis: syn::Visibility::Public(syn::token::Pub {
-                span: proc_macro2::Span::call_site(),
-            }),
-            mutability: syn::FieldMutability::None,
-            ident: Some(name.ident),
-            colon_token: Some(Colon {
-                spans: [proc_macro2::Span::call_site()],
-            }),
-            ty: *param.ty,
-        };
-        struct_fields.named.push_value(field);
-        if let Some(comma) = comma {
-            struct_fields.named.push_punct(comma);
-        }
+        let mut ty = Punctuated::<_, PathSep>::new();
+        ty.push_value(PathSegment {
+            ident: anon_ty.clone(),
+            arguments: syn::PathArguments::None,
+        });
+        struct_field_types.push(Type::Path(TypePath {
+            qself: None,
+            path: Path {
+                leading_colon: None,
+                segments: ty,
+            },
+        }));
+        struct_generics.push(anon_ty);
+        param_ty.push(*param.ty);
     }
 
     let output_ty = match sig.output.clone() {
@@ -136,33 +134,79 @@ pub fn with_simd(
     let fn_name = sig.ident.clone();
 
     let arch = attr.value;
+    let new_fn_generics = new_fn_sig.generics.clone();
+    let params = new_fn_generics.params.clone();
+    let generics = params.into_iter().collect::<Vec<_>>();
+    let non_lt_generics_names = generics
+        .iter()
+        .map(|p| match p {
+            GenericParam::Type(TypeParam { ident, .. })
+            | GenericParam::Const(ConstParam { ident, .. }) => {
+                quote! { #ident, }
+            }
+            _ => quote! {},
+        })
+        .collect::<Vec<_>>();
+    let generics_decl = generics
+        .iter()
+        .map(|p| match p {
+            GenericParam::Lifetime(LifetimeParam {
+                lifetime,
+                colon_token,
+                bounds,
+                ..
+            }) => {
+                quote! { #lifetime #colon_token #bounds }
+            }
+            GenericParam::Type(TypeParam {
+                ident,
+                colon_token,
+                bounds,
+                ..
+            }) => {
+                quote! { #ident #colon_token #bounds }
+            }
+            GenericParam::Const(ConstParam {
+                const_token,
+                ident,
+                colon_token,
+                ty,
+                ..
+            }) => {
+                quote! { #const_token #ident #colon_token #ty }
+            }
+        })
+        .collect::<Vec<_>>();
+    let generics_where_clause = new_fn_generics.where_clause;
 
-    quote! {
+    let code = quote! {
         #(#attrs)*
         #vis #new_fn_sig {
             #[allow(non_camel_case_types)]
-            struct #name<#struct_generics> #struct_fields
+            struct #name<#(#struct_generics,)*> (#(#struct_field_types,)*);
 
-            impl<#struct_generics> ::pulp::WithSimd for #name<#(#struct_generics_lifetimes,)*
-    #(#struct_generics_names,)*> {             type Output = #output_ty;
+            impl<#(#generics_decl,)*> ::pulp::WithSimd for #name<
+                #(#param_ty,)*
+            > #generics_where_clause {
+                type Output = #output_ty;
 
                 #[inline(always)]
-                fn with_simd<__S: ::pulp::Simd>(self, __simd: __S) -> <Self as
-    ::pulp::WithSimd>::Output {                 let Self { #(#struct_field_names,)* } = self;
+                fn with_simd<__S: ::pulp::Simd>(self, __simd: __S) -> <Self as ::pulp::WithSimd>::Output {
+                    let Self ( #(#struct_field_names,)* ) = self;
                     #[allow(unused_unsafe)]
                     unsafe {
                         #fn_name::<__S,
-                        #(#struct_generics_names,)*
+                        #(#non_lt_generics_names)*
                         >(__simd, #(#struct_field_names,)*)
                     }
                 }
             }
 
-            (#arch).dispatch( #name::<#(#struct_generics_names,)*> { #(#struct_field_names,)* } )
+            (#arch).dispatch( #name ( #(#struct_field_names,)* ) )
         }
 
         #(#attrs)*
         #vis #sig #block
-    }
-    .into()
+    };
+    code.into()
 }

pulp/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pulp"
-version = "0.18.5"
+version = "0.18.6"
 edition = "2021"
 authors = ["sarah <>"]
 description = "Safe generic simd"
@@ -10,7 +10,7 @@ license = "MIT"
 keywords = ["simd"]
 
 [dependencies]
-pulp-macro = { version = "0.1.0", path = "../pulp-macro", optional = true }
+pulp-macro = { version = "0.1.1", path = "../pulp-macro", optional = true }
 bytemuck = "1"
 num-complex = { version = "0.4.4", default-features = false, features = ["bytemuck"] }
 libm = { version = "0.2", default-features = false }