diff options
Diffstat (limited to '')
| -rw-r--r-- | askama_derive/src/generator.rs | 159 |
1 files changed, 105 insertions, 54 deletions
diff --git a/askama_derive/src/generator.rs b/askama_derive/src/generator.rs index 2040cac..c1a8ebe 100644 --- a/askama_derive/src/generator.rs +++ b/askama_derive/src/generator.rs @@ -2040,60 +2040,111 @@ enum Writable<'a> { // because they are not allowed to be raw identifiers, and *loop* // because it's used something like a keyword in the template // language. -static USE_RAW: [(&str, &str); 47] = [ - ("as", "r#as"), - ("break", "r#break"), - ("const", "r#const"), - ("continue", "r#continue"), - ("crate", "r#crate"), - ("else", "r#else"), - ("enum", "r#enum"), - ("extern", "r#extern"), - ("false", "r#false"), - ("fn", "r#fn"), - ("for", "r#for"), - ("if", "r#if"), - ("impl", "r#impl"), - ("in", "r#in"), - ("let", "r#let"), - ("match", "r#match"), - ("mod", "r#mod"), - ("move", "r#move"), - ("mut", "r#mut"), - ("pub", "r#pub"), - ("ref", "r#ref"), - ("return", "r#return"), - ("static", "r#static"), - ("struct", "r#struct"), - ("trait", "r#trait"), - ("true", "r#true"), - ("type", "r#type"), - ("unsafe", "r#unsafe"), - ("use", "r#use"), - ("where", "r#where"), - ("while", "r#while"), - ("async", "r#async"), - ("await", "r#await"), - ("dyn", "r#dyn"), - ("abstract", "r#abstract"), - ("become", "r#become"), - ("box", "r#box"), - ("do", "r#do"), - ("final", "r#final"), - ("macro", "r#macro"), - ("override", "r#override"), - ("priv", "r#priv"), - ("typeof", "r#typeof"), - ("unsized", "r#unsized"), - ("virtual", "r#virtual"), - ("yield", "r#yield"), - ("try", "r#try"), -]; - fn normalize_identifier(ident: &str) -> &str { - if let Some(word) = USE_RAW.iter().find(|x| x.0 == ident) { - word.1 - } else { - ident + // This table works for as long as the replacement string is the original string + // prepended with "r#". The strings get right-padded to the same length with b'_'. + // While the code does not need it, please keep the list sorted when adding new + // keywords. + + // FIXME: Replace with `[core:ascii::Char; MAX_REPL_LEN]` once + // <https://github.com/rust-lang/rust/issues/110998> is stable. + + const MAX_KW_LEN: usize = 8; + const MAX_REPL_LEN: usize = MAX_KW_LEN + 2; + + const KW0: &[[u8; MAX_REPL_LEN]] = &[]; + const KW1: &[[u8; MAX_REPL_LEN]] = &[]; + const KW2: &[[u8; MAX_REPL_LEN]] = &[ + *b"r#as______", + *b"r#do______", + *b"r#fn______", + *b"r#if______", + *b"r#in______", + ]; + const KW3: &[[u8; MAX_REPL_LEN]] = &[ + *b"r#box_____", + *b"r#dyn_____", + *b"r#for_____", + *b"r#let_____", + *b"r#mod_____", + *b"r#mut_____", + *b"r#pub_____", + *b"r#ref_____", + *b"r#try_____", + *b"r#use_____", + ]; + const KW4: &[[u8; MAX_REPL_LEN]] = &[ + *b"r#else____", + *b"r#enum____", + *b"r#impl____", + *b"r#move____", + *b"r#priv____", + *b"r#true____", + *b"r#type____", + ]; + const KW5: &[[u8; MAX_REPL_LEN]] = &[ + *b"r#async___", + *b"r#await___", + *b"r#break___", + *b"r#const___", + *b"r#crate___", + *b"r#false___", + *b"r#final___", + *b"r#macro___", + *b"r#match___", + *b"r#trait___", + *b"r#where___", + *b"r#while___", + *b"r#yield___", + ]; + const KW6: &[[u8; MAX_REPL_LEN]] = &[ + *b"r#become__", + *b"r#extern__", + *b"r#return__", + *b"r#static__", + *b"r#struct__", + *b"r#typeof__", + *b"r#unsafe__", + ]; + const KW7: &[[u8; MAX_REPL_LEN]] = &[*b"r#unsized_", *b"r#virtual_"]; + const KW8: &[[u8; MAX_REPL_LEN]] = &[*b"r#abstract", *b"r#continue", *b"r#override"]; + + const KWS: &[&[[u8; MAX_REPL_LEN]]] = &[KW0, KW1, KW2, KW3, KW4, KW5, KW6, KW7, KW8]; + + // Ensure that all strings are ASCII, because we use `from_utf8_unchecked()` further down. + const _: () = { + let mut i = 0; + while i < KWS.len() { + let mut j = 0; + while KWS[i].len() < j { + let mut k = 0; + while KWS[i][j].len() < k { + assert!(KWS[i][j][k].is_ascii()); + k += 1; + } + j += 1; + } + i += 1; + } + }; + + if ident.len() > MAX_KW_LEN { + return ident; } + let kws = KWS[ident.len()]; + + let mut padded_ident = [b'_'; MAX_KW_LEN]; + padded_ident[..ident.len()].copy_from_slice(ident.as_bytes()); + + // Since the individual buckets are quite short, a linear search is faster than a binary search. + let replacement = match kws + .iter() + .find(|probe| padded_ident == <[u8; MAX_KW_LEN]>::try_from(&probe[2..]).unwrap()) + { + Some(replacement) => replacement, + None => return ident, + }; + + // SAFETY: We know that the input byte slice is pure-ASCII. + unsafe { std::str::from_utf8_unchecked(&replacement[..ident.len() + 2]) } } |