diff options
Diffstat (limited to '')
| -rw-r--r-- | compiler/rustc_lexer/src/lib.rs | 76 |
1 files changed, 44 insertions, 32 deletions
diff --git a/compiler/rustc_lexer/src/lib.rs b/compiler/rustc_lexer/src/lib.rs index a79c98264..51515976e 100644 --- a/compiler/rustc_lexer/src/lib.rs +++ b/compiler/rustc_lexer/src/lib.rs @@ -29,9 +29,11 @@ pub mod unescape; #[cfg(test)] mod tests; +pub use crate::cursor::Cursor; + use self::LiteralKind::*; use self::TokenKind::*; -use crate::cursor::{Cursor, EOF_CHAR}; +use crate::cursor::EOF_CHAR; use std::convert::TryFrom; /// Parsed token. @@ -55,29 +57,42 @@ pub enum TokenKind { // Multi-char tokens: /// "// comment" LineComment { doc_style: Option<DocStyle> }, + /// `/* block comment */` /// - /// Block comments can be recursive, so the sequence like `/* /* */` + /// Block comments can be recursive, so a sequence like `/* /* */` /// will not be considered terminated and will result in a parsing error. BlockComment { doc_style: Option<DocStyle>, terminated: bool }, - /// Any whitespace characters sequence. + + /// Any whitespace character sequence. Whitespace, + /// "ident" or "continue" - /// At this step keywords are also considered identifiers. + /// + /// At this step, keywords are also considered identifiers. Ident, + /// Like the above, but containing invalid unicode codepoints. InvalidIdent, + /// "r#ident" RawIdent, - /// An unknown prefix like `foo#`, `foo'`, `foo"`. Note that only the + + /// An unknown prefix, like `foo#`, `foo'`, `foo"`. + /// + /// Note that only the /// prefix (`foo`) is included in the token, not the separator (which is /// lexed as its own distinct token). In Rust 2021 and later, reserved /// prefixes are reported as errors; in earlier editions, they result in a /// (allowed by default) lint, and are treated as regular identifier /// tokens. UnknownPrefix, - /// "12_u8", "1.0e-40", "b"123"". See `LiteralKind` for more details. + + /// Examples: `"12_u8"`, `"1.0e-40"`, `b"123`. + /// + /// See [LiteralKind] for more details. Literal { kind: LiteralKind, suffix_start: u32 }, + /// "'a" Lifetime { starts_with_number: bool }, @@ -139,6 +154,9 @@ pub enum TokenKind { /// Unknown token, not expected by the lexer, e.g. "№" Unknown, + + /// End of input. + Eof, } #[derive(Clone, Copy, Debug, PartialEq, Eq)] @@ -219,13 +237,6 @@ pub fn strip_shebang(input: &str) -> Option<usize> { None } -/// Parses the first token from the provided input string. -#[inline] -pub fn first_token(input: &str) -> Token { - debug_assert!(!input.is_empty()); - Cursor::new(input).advance_token() -} - /// Validates a raw string literal. Used for getting more information about a /// problem with a `RawStr`/`RawByteStr` with a `None` field. #[inline] @@ -243,12 +254,8 @@ pub fn validate_raw_str(input: &str, prefix_len: u32) -> Result<(), RawStrError> pub fn tokenize(input: &str) -> impl Iterator<Item = Token> + '_ { let mut cursor = Cursor::new(input); std::iter::from_fn(move || { - if cursor.is_eof() { - None - } else { - cursor.reset_len_consumed(); - Some(cursor.advance_token()) - } + let token = cursor.advance_token(); + if token.kind != TokenKind::Eof { Some(token) } else { None } }) } @@ -311,8 +318,11 @@ pub fn is_ident(string: &str) -> bool { impl Cursor<'_> { /// Parses a token from the input string. - fn advance_token(&mut self) -> Token { - let first_char = self.bump().unwrap(); + pub fn advance_token(&mut self) -> Token { + let first_char = match self.bump() { + Some(c) => c, + None => return Token::new(TokenKind::Eof, 0), + }; let token_kind = match first_char { // Slash, comment or block comment. '/' => match self.first() { @@ -329,7 +339,7 @@ impl Cursor<'_> { ('#', c1) if is_id_start(c1) => self.raw_ident(), ('#', _) | ('"', _) => { let res = self.raw_double_quoted_string(1); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); if res.is_ok() { self.eat_literal_suffix(); } @@ -344,7 +354,7 @@ impl Cursor<'_> { ('\'', _) => { self.bump(); let terminated = self.single_quoted_string(); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); if terminated { self.eat_literal_suffix(); } @@ -354,7 +364,7 @@ impl Cursor<'_> { ('"', _) => { self.bump(); let terminated = self.double_quoted_string(); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); if terminated { self.eat_literal_suffix(); } @@ -364,7 +374,7 @@ impl Cursor<'_> { ('r', '"') | ('r', '#') => { self.bump(); let res = self.raw_double_quoted_string(2); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); if res.is_ok() { self.eat_literal_suffix(); } @@ -381,7 +391,7 @@ impl Cursor<'_> { // Numeric literal. c @ '0'..='9' => { let literal_kind = self.number(c); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); self.eat_literal_suffix(); TokenKind::Literal { kind: literal_kind, suffix_start } } @@ -420,7 +430,7 @@ impl Cursor<'_> { // String literal. '"' => { let terminated = self.double_quoted_string(); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); if terminated { self.eat_literal_suffix(); } @@ -433,7 +443,9 @@ impl Cursor<'_> { } _ => Unknown, }; - Token::new(token_kind, self.len_consumed()) + let res = Token::new(token_kind, self.pos_within_token()); + self.reset_pos_within_token(); + res } fn line_comment(&mut self) -> TokenKind { @@ -618,7 +630,7 @@ impl Cursor<'_> { if !can_be_a_lifetime { let terminated = self.single_quoted_string(); - let suffix_start = self.len_consumed(); + let suffix_start = self.pos_within_token(); if terminated { self.eat_literal_suffix(); } @@ -643,7 +655,7 @@ impl Cursor<'_> { if self.first() == '\'' { self.bump(); let kind = Char { terminated: true }; - Literal { kind, suffix_start: self.len_consumed() } + Literal { kind, suffix_start: self.pos_within_token() } } else { Lifetime { starts_with_number } } @@ -724,7 +736,7 @@ impl Cursor<'_> { fn raw_string_unvalidated(&mut self, prefix_len: u32) -> Result<u32, RawStrError> { debug_assert!(self.prev() == 'r'); - let start_pos = self.len_consumed(); + let start_pos = self.pos_within_token(); let mut possible_terminator_offset = None; let mut max_hashes = 0; @@ -778,7 +790,7 @@ impl Cursor<'_> { // Keep track of possible terminators to give a hint about // where there might be a missing terminator possible_terminator_offset = - Some(self.len_consumed() - start_pos - n_end_hashes + prefix_len); + Some(self.pos_within_token() - start_pos - n_end_hashes + prefix_len); max_hashes = n_end_hashes; } } |