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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184
extern crate proc_macro; use proc_macro::TokenStream; use proc_macro2::Ident; use quote::{format_ident, quote, ToTokens}; use syn::{parse_macro_input, DeriveInput, LitStr}; mod dfa; mod nfa; #[proc_macro_attribute] pub fn bird_machine(args: TokenStream, input: TokenStream) -> TokenStream { let input = parse_macro_input!(input as DeriveInput); let input_regex = parse_macro_input!(args as LitStr); let input_type_name = &input.ident; let input_lifetimes: Vec<_> = input.generics.lifetimes().collect(); let lifetime = match input_lifetimes.as_slice() { [] => quote! { 'unrestricted }, [lt] => quote! { #lt }, _ => panic!("multiple lifetime generics, what is this, pls to halp"), }; let machine_fn = format_ident!("bird_machine_for_{}", input_type_name); let machine = build_machine(&input_regex, &machine_fn); eprintln!("{}", &machine); let (_, ty_generics, where_clause) = input.generics.split_for_impl(); let impl_decl = quote! { impl<#lifetime> ::bird_machine::Machine<#lifetime> for #input_type_name #ty_generics #where_clause }; let original_regex = quote! { const ORIGINAL_REGEX: &'static str = #input_regex; }; let captures = quote! { fn captures(text: &#lifetime str) -> Option<Self> { todo!() } }; let captures_iter = quote! { type CaptureIterator = ::std::iter::Empty<Self>; fn captures_iter(text: &#lifetime str) -> Self::CaptureIterator { todo!() } }; let find = quote! { fn find(text: &#lifetime str) -> Option<::bird_machine::Match<#lifetime>> { todo!() } }; let find_at = quote! { fn find_at(text: &#lifetime str, start: usize) -> Option<::bird_machine::Match<#lifetime>> { todo!() } }; let find_iter = quote! { type FindIterator = ::std::iter::Empty<::bird_machine::Match<#lifetime>>; fn find_iter(text: &#lifetime str) -> Self::FindIterator { todo!() } }; let is_match = quote! { fn is_match(text: &#lifetime str) -> bool { #machine_fn(text) } }; let is_match_at = quote! { fn is_match_at(text: &#lifetime str, start: usize) -> bool { todo!() } }; let replace = quote! { fn replace( text: &#lifetime str, rep: impl ::bird_machine::Replacer<#lifetime, Self>, ) -> ::std::borrow::Cow<#lifetime, str> { todo!() } }; let replace_all = quote! { fn replace_all( text: &#lifetime str, rep: impl ::bird_machine::Replacer<#lifetime, Self>, ) -> ::std::borrow::Cow<#lifetime, str> { todo!() } }; let replacen = quote! { fn replacen( text: &#lifetime str, limit: usize, rep: impl ::bird_machine::Replacer<#lifetime, Self>, ) -> ::std::borrow::Cow<#lifetime, str> { todo!() } }; let split = quote! { type SplitIterator = ::std::iter::Empty<&#lifetime str>; fn split(text: &#lifetime str) -> Self::SplitIterator { todo!() } }; let splitn = quote! { type SplitNIterator = ::std::iter::Empty<&#lifetime str>; fn splitn(text: &#lifetime str, limit: usize) -> Self::SplitNIterator { todo!() } }; let tokens = quote! { #input #machine #impl_decl { #original_regex #captures #captures_iter #find #find_at #find_iter #is_match #is_match_at #replace #replace_all #replacen #split #splitn } }; eprintln!( "{impl_decl} {{\n\n\ {original_regex}\n\n\ {captures}\n\n\ {captures_iter}\n\n\ {find}\n\n\ {find_at}\n\n\ {find_iter}\n\n\ {is_match}\n\n\ {is_match_at}\n\n\ {replace}\n\n\ {replace_all}\n\n\ {replacen}\n\n\ {split}\n\n\ {splitn}\n\n\ }}", impl_decl = impl_decl, original_regex = original_regex, captures = captures, captures_iter = captures_iter, find = find, find_at = find_at, find_iter = find_iter, is_match = is_match, is_match_at = is_match_at, replace = replace, replace_all = replace_all, replacen = replacen, split = split, splitn = splitn, ); tokens.into() } fn build_machine(regex: &LitStr, fn_name: &Ident) -> proc_macro2::TokenStream { let regex_text = regex.value(); let regex_ir = regex_syntax::Parser::new().parse(®ex_text); let regex_ir = match regex_ir { Ok(x) => x, Err(err) => panic!("error compiling regex {}: {}", regex.to_token_stream(), err), }; let built_nfa = nfa::NFA::from(®ex_ir); let dfa = dfa::DFA::from(built_nfa); quote! { fn #fn_name(input: &str) -> bool { #dfa } } }