1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164
use syn::{Field, Data, Fields, Variant, Ident, Meta, NestedMeta, Attribute, Lit, LitStr}; use syn::spanned::Spanned; use syn::punctuated::Punctuated; use syn::token::Comma; use quote::{quote, quote_spanned}; use proc_macro2::TokenStream; pub fn normalized_fields(fields: &Fields) -> Vec<(TokenStream, Field)> { let mut ret = Vec::new(); match fields { Fields::Named(ref fields) => { for f in fields.named.iter() { let name = &f.ident; ret.push((quote_spanned! { f.span() => #name }, f.clone())); } }, Fields::Unnamed(ref fields) => { for (i, f) in fields.unnamed.iter().enumerate() { let i = syn::Index::from(i); ret.push((quote_spanned! { f.span() => #i }, f.clone())) } }, Fields::Unit => (), } ret } pub fn is_fields_variant_unnamed(variant: &Variant) -> bool { match variant.fields { Fields::Named(_) => false, Fields::Unnamed(_) => true, Fields::Unit => false, } } pub fn normalized_variant_match_cause(enum_name: &Ident, variant: &Variant, inner: TokenStream) -> TokenStream { let ident = &variant.ident; match variant.fields { Fields::Named(ref fields) => { let fields = fields.named .iter() .map(|f| { let name = &f.ident; quote_spanned! { f.span() => #name } }); quote! { #enum_name::#ident { #(#fields),* } => { #inner }, } }, Fields::Unnamed(ref fields) => { let fields = fields.unnamed .iter() .enumerate() .map(|(i, f)| { let name = Ident::new(&format!("v{}", i), f.span()); quote_spanned! { f.span() => #name } }) .collect::<Vec<_>>(); let fields = quote! { #(#fields,)* }; quote! { #enum_name::#ident(#fields) => { let variant = (#fields); #inner }, } }, Fields::Unit => { quote! { #enum_name::#ident => { #inner }, } }, } } pub fn struct_fields(data: &Data) -> Option<&Punctuated<Field, Comma>> { match data { Data::Struct(ref data) => { match data.fields { Fields::Named(ref fields) => Some(&fields.named), Fields::Unnamed(_) => None, Fields::Unit => None, } }, Data::Enum(_) | Data::Union(_) => None, } } pub fn has_attribute(prefix: &str, attrs: &[Attribute], name: &str) -> bool { for attr in attrs { let meta = match attr.parse_meta() { Ok(meta) => meta, Err(_) => continue, }; match meta { Meta::List(list) => { if list.ident == prefix { for nested in &list.nested { match nested { NestedMeta::Meta(Meta::Word(value)) => { if value == name { return true } }, _ => (), } } } }, _ => (), } } false } pub fn attribute_value(prefix: &str, attrs: &[Attribute], name: &str) -> Option<LitStr> { for attr in attrs { let meta = match attr.parse_meta() { Ok(meta) => meta, Err(_) => continue, }; match meta { Meta::List(list) => { if list.ident == prefix { for nested in &list.nested { match nested { NestedMeta::Meta(Meta::NameValue(value)) => { if value.ident == name { match &value.lit { Lit::Str(s) => { return Some(s.clone()) }, _ => (), } } }, _ => (), } } } }, _ => (), } } None }