| // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use ast; |
| use codemap::{BytePos, CharPos, CodeMap, Pos, Span}; |
| use codemap; |
| use diagnostic::SpanHandler; |
| use ext::tt::transcribe::tt_next_token; |
| use parse::token::str_to_ident; |
| use parse::token; |
| use str::char_at; |
| |
| use std::borrow::Cow; |
| use std::char; |
| use std::mem::replace; |
| use std::rc::Rc; |
| |
| pub use ext::tt::transcribe::{TtReader, new_tt_reader, new_tt_reader_with_doc_flag}; |
| |
| pub mod comments; |
| |
| pub trait Reader { |
| fn is_eof(&self) -> bool; |
| fn next_token(&mut self) -> TokenAndSpan; |
| /// Report a fatal error with the current span. |
| fn fatal(&self, &str) -> !; |
| /// Report a non-fatal error with the current span. |
| fn err(&self, &str); |
| fn peek(&self) -> TokenAndSpan; |
| /// Get a token the parser cares about. |
| fn real_token(&mut self) -> TokenAndSpan { |
| let mut t = self.next_token(); |
| loop { |
| match t.tok { |
| token::Whitespace | token::Comment | token::Shebang(_) => { |
| t = self.next_token(); |
| }, |
| _ => break |
| } |
| } |
| t |
| } |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Debug)] |
| pub struct TokenAndSpan { |
| pub tok: token::Token, |
| pub sp: Span, |
| } |
| |
| pub struct StringReader<'a> { |
| pub span_diagnostic: &'a SpanHandler, |
| /// The absolute offset within the codemap of the next character to read |
| pub pos: BytePos, |
| /// The absolute offset within the codemap of the last character read(curr) |
| pub last_pos: BytePos, |
| /// The column of the next character to read |
| pub col: CharPos, |
| /// The last character to be read |
| pub curr: Option<char>, |
| pub filemap: Rc<codemap::FileMap>, |
| /* cached: */ |
| pub peek_tok: token::Token, |
| pub peek_span: Span, |
| |
| // cache a direct reference to the source text, so that we don't have to |
| // retrieve it via `self.filemap.src.as_ref().unwrap()` all the time. |
| source_text: Rc<String> |
| } |
| |
| impl<'a> Reader for StringReader<'a> { |
| fn is_eof(&self) -> bool { self.curr.is_none() } |
| /// Return the next token. EFFECT: advances the string_reader. |
| fn next_token(&mut self) -> TokenAndSpan { |
| let ret_val = TokenAndSpan { |
| tok: replace(&mut self.peek_tok, token::Underscore), |
| sp: self.peek_span, |
| }; |
| self.advance_token(); |
| ret_val |
| } |
| fn fatal(&self, m: &str) -> ! { |
| self.fatal_span(self.peek_span, m) |
| } |
| fn err(&self, m: &str) { |
| self.err_span(self.peek_span, m) |
| } |
| fn peek(&self) -> TokenAndSpan { |
| // FIXME(pcwalton): Bad copy! |
| TokenAndSpan { |
| tok: self.peek_tok.clone(), |
| sp: self.peek_span, |
| } |
| } |
| } |
| |
| impl<'a> Reader for TtReader<'a> { |
| fn is_eof(&self) -> bool { |
| self.cur_tok == token::Eof |
| } |
| fn next_token(&mut self) -> TokenAndSpan { |
| let r = tt_next_token(self); |
| debug!("TtReader: r={:?}", r); |
| r |
| } |
| fn fatal(&self, m: &str) -> ! { |
| panic!(self.sp_diag.span_fatal(self.cur_span, m)); |
| } |
| fn err(&self, m: &str) { |
| self.sp_diag.span_err(self.cur_span, m); |
| } |
| fn peek(&self) -> TokenAndSpan { |
| TokenAndSpan { |
| tok: self.cur_tok.clone(), |
| sp: self.cur_span, |
| } |
| } |
| } |
| |
| impl<'a> StringReader<'a> { |
| /// For comments.rs, which hackily pokes into pos and curr |
| pub fn new_raw<'b>(span_diagnostic: &'b SpanHandler, |
| filemap: Rc<codemap::FileMap>) -> StringReader<'b> { |
| if filemap.src.is_none() { |
| span_diagnostic.handler.bug(&format!("Cannot lex filemap without source: {}", |
| filemap.name)[..]); |
| } |
| |
| let source_text = (*filemap.src.as_ref().unwrap()).clone(); |
| |
| let mut sr = StringReader { |
| span_diagnostic: span_diagnostic, |
| pos: filemap.start_pos, |
| last_pos: filemap.start_pos, |
| col: CharPos(0), |
| curr: Some('\n'), |
| filemap: filemap, |
| /* dummy values; not read */ |
| peek_tok: token::Eof, |
| peek_span: codemap::DUMMY_SP, |
| source_text: source_text |
| }; |
| sr.bump(); |
| sr |
| } |
| |
| pub fn new<'b>(span_diagnostic: &'b SpanHandler, |
| filemap: Rc<codemap::FileMap>) -> StringReader<'b> { |
| let mut sr = StringReader::new_raw(span_diagnostic, filemap); |
| sr.advance_token(); |
| sr |
| } |
| |
| pub fn curr_is(&self, c: char) -> bool { |
| self.curr == Some(c) |
| } |
| |
| /// Report a fatal lexical error with a given span. |
| pub fn fatal_span(&self, sp: Span, m: &str) -> ! { |
| panic!(self.span_diagnostic.span_fatal(sp, m)) |
| } |
| |
| /// Report a lexical error with a given span. |
| pub fn err_span(&self, sp: Span, m: &str) { |
| self.span_diagnostic.span_err(sp, m) |
| } |
| |
| /// Report a fatal error spanning [`from_pos`, `to_pos`). |
| fn fatal_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) -> ! { |
| self.fatal_span(codemap::mk_sp(from_pos, to_pos), m) |
| } |
| |
| /// Report a lexical error spanning [`from_pos`, `to_pos`). |
| fn err_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) { |
| self.err_span(codemap::mk_sp(from_pos, to_pos), m) |
| } |
| |
| /// Report a lexical error spanning [`from_pos`, `to_pos`), appending an |
| /// escaped character to the error message |
| fn fatal_span_char(&self, from_pos: BytePos, to_pos: BytePos, m: &str, c: char) -> ! { |
| let mut m = m.to_string(); |
| m.push_str(": "); |
| for c in c.escape_default() { m.push(c) } |
| self.fatal_span_(from_pos, to_pos, &m[..]); |
| } |
| |
| /// Report a lexical error spanning [`from_pos`, `to_pos`), appending an |
| /// escaped character to the error message |
| fn err_span_char(&self, from_pos: BytePos, to_pos: BytePos, m: &str, c: char) { |
| let mut m = m.to_string(); |
| m.push_str(": "); |
| for c in c.escape_default() { m.push(c) } |
| self.err_span_(from_pos, to_pos, &m[..]); |
| } |
| |
| /// Report a lexical error spanning [`from_pos`, `to_pos`), appending the |
| /// offending string to the error message |
| fn fatal_span_verbose(&self, from_pos: BytePos, to_pos: BytePos, mut m: String) -> ! { |
| m.push_str(": "); |
| let from = self.byte_offset(from_pos).to_usize(); |
| let to = self.byte_offset(to_pos).to_usize(); |
| m.push_str(&self.source_text[from..to]); |
| self.fatal_span_(from_pos, to_pos, &m[..]); |
| } |
| |
| /// Advance peek_tok and peek_span to refer to the next token, and |
| /// possibly update the interner. |
| fn advance_token(&mut self) { |
| match self.scan_whitespace_or_comment() { |
| Some(comment) => { |
| self.peek_span = comment.sp; |
| self.peek_tok = comment.tok; |
| }, |
| None => { |
| if self.is_eof() { |
| self.peek_tok = token::Eof; |
| } else { |
| let start_bytepos = self.last_pos; |
| self.peek_tok = self.next_token_inner(); |
| self.peek_span = codemap::mk_sp(start_bytepos, |
| self.last_pos); |
| }; |
| } |
| } |
| } |
| |
| fn byte_offset(&self, pos: BytePos) -> BytePos { |
| (pos - self.filemap.start_pos) |
| } |
| |
| /// Calls `f` with a string slice of the source text spanning from `start` |
| /// up to but excluding `self.last_pos`, meaning the slice does not include |
| /// the character `self.curr`. |
| pub fn with_str_from<T, F>(&self, start: BytePos, f: F) -> T where |
| F: FnOnce(&str) -> T, |
| { |
| self.with_str_from_to(start, self.last_pos, f) |
| } |
| |
| /// Create a Name from a given offset to the current offset, each |
| /// adjusted 1 towards each other (assumes that on either side there is a |
| /// single-byte delimiter). |
| pub fn name_from(&self, start: BytePos) -> ast::Name { |
| debug!("taking an ident from {:?} to {:?}", start, self.last_pos); |
| self.with_str_from(start, token::intern) |
| } |
| |
| /// As name_from, with an explicit endpoint. |
| pub fn name_from_to(&self, start: BytePos, end: BytePos) -> ast::Name { |
| debug!("taking an ident from {:?} to {:?}", start, end); |
| self.with_str_from_to(start, end, token::intern) |
| } |
| |
| /// Calls `f` with a string slice of the source text spanning from `start` |
| /// up to but excluding `end`. |
| fn with_str_from_to<T, F>(&self, start: BytePos, end: BytePos, f: F) -> T where |
| F: FnOnce(&str) -> T, |
| { |
| f(&self.source_text[self.byte_offset(start).to_usize().. |
| self.byte_offset(end).to_usize()]) |
| } |
| |
| /// Converts CRLF to LF in the given string, raising an error on bare CR. |
| fn translate_crlf<'b>(&self, start: BytePos, |
| s: &'b str, errmsg: &'b str) -> Cow<'b, str> { |
| let mut i = 0; |
| while i < s.len() { |
| let ch = char_at(s, i); |
| let next = i + ch.len_utf8(); |
| if ch == '\r' { |
| if next < s.len() && char_at(s, next) == '\n' { |
| return translate_crlf_(self, start, s, errmsg, i).into(); |
| } |
| let pos = start + BytePos(i as u32); |
| let end_pos = start + BytePos(next as u32); |
| self.err_span_(pos, end_pos, errmsg); |
| } |
| i = next; |
| } |
| return s.into(); |
| |
| fn translate_crlf_(rdr: &StringReader, start: BytePos, |
| s: &str, errmsg: &str, mut i: usize) -> String { |
| let mut buf = String::with_capacity(s.len()); |
| let mut j = 0; |
| while i < s.len() { |
| let ch = char_at(s, i); |
| let next = i + ch.len_utf8(); |
| if ch == '\r' { |
| if j < i { buf.push_str(&s[j..i]); } |
| j = next; |
| if next >= s.len() || char_at(s, next) != '\n' { |
| let pos = start + BytePos(i as u32); |
| let end_pos = start + BytePos(next as u32); |
| rdr.err_span_(pos, end_pos, errmsg); |
| } |
| } |
| i = next; |
| } |
| if j < s.len() { buf.push_str(&s[j..]); } |
| buf |
| } |
| } |
| |
| |
| /// Advance the StringReader by one character. If a newline is |
| /// discovered, add it to the FileMap's list of line start offsets. |
| pub fn bump(&mut self) { |
| self.last_pos = self.pos; |
| let current_byte_offset = self.byte_offset(self.pos).to_usize(); |
| if current_byte_offset < self.source_text.len() { |
| assert!(self.curr.is_some()); |
| let last_char = self.curr.unwrap(); |
| let ch = char_at(&self.source_text, current_byte_offset); |
| let next = current_byte_offset + ch.len_utf8(); |
| let byte_offset_diff = next - current_byte_offset; |
| self.pos = self.pos + Pos::from_usize(byte_offset_diff); |
| self.curr = Some(ch); |
| self.col = self.col + CharPos(1); |
| if last_char == '\n' { |
| self.filemap.next_line(self.last_pos); |
| self.col = CharPos(0); |
| } |
| |
| if byte_offset_diff > 1 { |
| self.filemap.record_multibyte_char(self.last_pos, byte_offset_diff); |
| } |
| } else { |
| self.curr = None; |
| } |
| } |
| |
| pub fn nextch(&self) -> Option<char> { |
| let offset = self.byte_offset(self.pos).to_usize(); |
| if offset < self.source_text.len() { |
| Some(char_at(&self.source_text, offset)) |
| } else { |
| None |
| } |
| } |
| |
| pub fn nextch_is(&self, c: char) -> bool { |
| self.nextch() == Some(c) |
| } |
| |
| pub fn nextnextch(&self) -> Option<char> { |
| let offset = self.byte_offset(self.pos).to_usize(); |
| let s = &self.source_text[..]; |
| if offset >= s.len() { return None } |
| let next = offset + char_at(s, offset).len_utf8(); |
| if next < s.len() { |
| Some(char_at(s, next)) |
| } else { |
| None |
| } |
| } |
| |
| pub fn nextnextch_is(&self, c: char) -> bool { |
| self.nextnextch() == Some(c) |
| } |
| |
| /// Eats <XID_start><XID_continue>*, if possible. |
| fn scan_optional_raw_name(&mut self) -> Option<ast::Name> { |
| if !ident_start(self.curr) { |
| return None |
| } |
| let start = self.last_pos; |
| while ident_continue(self.curr) { |
| self.bump(); |
| } |
| |
| self.with_str_from(start, |string| { |
| if string == "_" { |
| None |
| } else { |
| Some(token::intern(string)) |
| } |
| }) |
| } |
| |
| /// PRECONDITION: self.curr is not whitespace |
| /// Eats any kind of comment. |
| fn scan_comment(&mut self) -> Option<TokenAndSpan> { |
| match self.curr { |
| Some(c) => { |
| if c.is_whitespace() { |
| self.span_diagnostic.span_err(codemap::mk_sp(self.last_pos, self.last_pos), |
| "called consume_any_line_comment, but there was whitespace"); |
| } |
| }, |
| None => { } |
| } |
| |
| if self.curr_is('/') { |
| match self.nextch() { |
| Some('/') => { |
| self.bump(); |
| self.bump(); |
| // line comments starting with "///" or "//!" are doc-comments |
| if self.curr_is('/') || self.curr_is('!') { |
| let start_bpos = self.pos - BytePos(3); |
| while !self.is_eof() { |
| match self.curr.unwrap() { |
| '\n' => break, |
| '\r' => { |
| if self.nextch_is('\n') { |
| // CRLF |
| break |
| } else { |
| self.err_span_(self.last_pos, self.pos, |
| "bare CR not allowed in doc-comment"); |
| } |
| } |
| _ => () |
| } |
| self.bump(); |
| } |
| return self.with_str_from(start_bpos, |string| { |
| // but comments with only more "/"s are not |
| let tok = if is_doc_comment(string) { |
| token::DocComment(token::intern(string)) |
| } else { |
| token::Comment |
| }; |
| |
| return Some(TokenAndSpan{ |
| tok: tok, |
| sp: codemap::mk_sp(start_bpos, self.last_pos) |
| }); |
| }); |
| } else { |
| let start_bpos = self.last_pos - BytePos(2); |
| while !self.curr_is('\n') && !self.is_eof() { self.bump(); } |
| return Some(TokenAndSpan { |
| tok: token::Comment, |
| sp: codemap::mk_sp(start_bpos, self.last_pos) |
| }); |
| } |
| } |
| Some('*') => { |
| self.bump(); self.bump(); |
| self.scan_block_comment() |
| } |
| _ => None |
| } |
| } else if self.curr_is('#') { |
| if self.nextch_is('!') { |
| |
| // Parse an inner attribute. |
| if self.nextnextch_is('[') { |
| return None; |
| } |
| |
| // I guess this is the only way to figure out if |
| // we're at the beginning of the file... |
| let cmap = CodeMap::new(); |
| cmap.files.borrow_mut().push(self.filemap.clone()); |
| let loc = cmap.lookup_char_pos_adj(self.last_pos); |
| debug!("Skipping a shebang"); |
| if loc.line == 1 && loc.col == CharPos(0) { |
| // FIXME: Add shebang "token", return it |
| let start = self.last_pos; |
| while !self.curr_is('\n') && !self.is_eof() { self.bump(); } |
| return Some(TokenAndSpan { |
| tok: token::Shebang(self.name_from(start)), |
| sp: codemap::mk_sp(start, self.last_pos) |
| }); |
| } |
| } |
| None |
| } else { |
| None |
| } |
| } |
| |
| /// If there is whitespace, shebang, or a comment, scan it. Otherwise, |
| /// return None. |
| fn scan_whitespace_or_comment(&mut self) -> Option<TokenAndSpan> { |
| match self.curr.unwrap_or('\0') { |
| // # to handle shebang at start of file -- this is the entry point |
| // for skipping over all "junk" |
| '/' | '#' => { |
| let c = self.scan_comment(); |
| debug!("scanning a comment {:?}", c); |
| c |
| }, |
| c if is_whitespace(Some(c)) => { |
| let start_bpos = self.last_pos; |
| while is_whitespace(self.curr) { self.bump(); } |
| let c = Some(TokenAndSpan { |
| tok: token::Whitespace, |
| sp: codemap::mk_sp(start_bpos, self.last_pos) |
| }); |
| debug!("scanning whitespace: {:?}", c); |
| c |
| }, |
| _ => None |
| } |
| } |
| |
| /// Might return a sugared-doc-attr |
| fn scan_block_comment(&mut self) -> Option<TokenAndSpan> { |
| // block comments starting with "/**" or "/*!" are doc-comments |
| let is_doc_comment = self.curr_is('*') || self.curr_is('!'); |
| let start_bpos = self.last_pos - BytePos(2); |
| |
| let mut level: isize = 1; |
| let mut has_cr = false; |
| while level > 0 { |
| if self.is_eof() { |
| let msg = if is_doc_comment { |
| "unterminated block doc-comment" |
| } else { |
| "unterminated block comment" |
| }; |
| let last_bpos = self.last_pos; |
| self.fatal_span_(start_bpos, last_bpos, msg); |
| } |
| let n = self.curr.unwrap(); |
| match n { |
| '/' if self.nextch_is('*') => { |
| level += 1; |
| self.bump(); |
| } |
| '*' if self.nextch_is('/') => { |
| level -= 1; |
| self.bump(); |
| } |
| '\r' => { |
| has_cr = true; |
| } |
| _ => () |
| } |
| self.bump(); |
| } |
| |
| self.with_str_from(start_bpos, |string| { |
| // but comments with only "*"s between two "/"s are not |
| let tok = if is_block_doc_comment(string) { |
| let string = if has_cr { |
| self.translate_crlf(start_bpos, string, |
| "bare CR not allowed in block doc-comment") |
| } else { string.into() }; |
| token::DocComment(token::intern(&string[..])) |
| } else { |
| token::Comment |
| }; |
| |
| Some(TokenAndSpan{ |
| tok: tok, |
| sp: codemap::mk_sp(start_bpos, self.last_pos) |
| }) |
| }) |
| } |
| |
| /// Scan through any digits (base `scan_radix`) or underscores, |
| /// and return how many digits there were. |
| /// |
| /// `real_radix` represents the true radix of the number we're |
| /// interested in, and errors will be emitted for any digits |
| /// between `real_radix` and `scan_radix`. |
| fn scan_digits(&mut self, real_radix: u32, scan_radix: u32) -> usize { |
| assert!(real_radix <= scan_radix); |
| let mut len = 0; |
| loop { |
| let c = self.curr; |
| if c == Some('_') { debug!("skipping a _"); self.bump(); continue; } |
| match c.and_then(|cc| cc.to_digit(scan_radix)) { |
| Some(_) => { |
| debug!("{:?} in scan_digits", c); |
| // check that the hypothetical digit is actually |
| // in range for the true radix |
| if c.unwrap().to_digit(real_radix).is_none() { |
| self.err_span_(self.last_pos, self.pos, |
| &format!("invalid digit for a base {} literal", |
| real_radix)); |
| } |
| len += 1; |
| self.bump(); |
| } |
| _ => return len |
| } |
| }; |
| } |
| |
| /// Lex a LIT_INTEGER or a LIT_FLOAT |
| fn scan_number(&mut self, c: char) -> token::Lit { |
| let mut num_digits; |
| let mut base = 10; |
| let start_bpos = self.last_pos; |
| |
| self.bump(); |
| |
| if c == '0' { |
| match self.curr.unwrap_or('\0') { |
| 'b' => { self.bump(); base = 2; num_digits = self.scan_digits(2, 10); } |
| 'o' => { self.bump(); base = 8; num_digits = self.scan_digits(8, 10); } |
| 'x' => { self.bump(); base = 16; num_digits = self.scan_digits(16, 16); } |
| '0'...'9' | '_' | '.' => { |
| num_digits = self.scan_digits(10, 10) + 1; |
| } |
| _ => { |
| // just a 0 |
| return token::Integer(self.name_from(start_bpos)); |
| } |
| } |
| } else if c.is_digit(10) { |
| num_digits = self.scan_digits(10, 10) + 1; |
| } else { |
| num_digits = 0; |
| } |
| |
| if num_digits == 0 { |
| self.err_span_(start_bpos, self.last_pos, "no valid digits found for number"); |
| return token::Integer(token::intern("0")); |
| } |
| |
| // might be a float, but don't be greedy if this is actually an |
| // integer literal followed by field/method access or a range pattern |
| // (`0..2` and `12.foo()`) |
| if self.curr_is('.') && !self.nextch_is('.') && !self.nextch().unwrap_or('\0') |
| .is_xid_start() { |
| // might have stuff after the ., and if it does, it needs to start |
| // with a number |
| self.bump(); |
| if self.curr.unwrap_or('\0').is_digit(10) { |
| self.scan_digits(10, 10); |
| self.scan_float_exponent(); |
| } |
| let last_pos = self.last_pos; |
| self.check_float_base(start_bpos, last_pos, base); |
| return token::Float(self.name_from(start_bpos)); |
| } else { |
| // it might be a float if it has an exponent |
| if self.curr_is('e') || self.curr_is('E') { |
| self.scan_float_exponent(); |
| let last_pos = self.last_pos; |
| self.check_float_base(start_bpos, last_pos, base); |
| return token::Float(self.name_from(start_bpos)); |
| } |
| // but we certainly have an integer! |
| return token::Integer(self.name_from(start_bpos)); |
| } |
| } |
| |
| /// Scan over `n_digits` hex digits, stopping at `delim`, reporting an |
| /// error if too many or too few digits are encountered. |
| fn scan_hex_digits(&mut self, |
| n_digits: usize, |
| delim: char, |
| below_0x7f_only: bool) |
| -> bool { |
| debug!("scanning {} digits until {:?}", n_digits, delim); |
| let start_bpos = self.last_pos; |
| let mut accum_int = 0; |
| |
| let mut valid = true; |
| for _ in 0..n_digits { |
| if self.is_eof() { |
| let last_bpos = self.last_pos; |
| self.fatal_span_(start_bpos, last_bpos, "unterminated numeric character escape"); |
| } |
| if self.curr_is(delim) { |
| let last_bpos = self.last_pos; |
| self.err_span_(start_bpos, last_bpos, "numeric character escape is too short"); |
| valid = false; |
| break; |
| } |
| let c = self.curr.unwrap_or('\x00'); |
| accum_int *= 16; |
| accum_int += c.to_digit(16).unwrap_or_else(|| { |
| self.err_span_char(self.last_pos, self.pos, |
| "illegal character in numeric character escape", c); |
| |
| valid = false; |
| 0 |
| }); |
| self.bump(); |
| } |
| |
| if below_0x7f_only && accum_int >= 0x80 { |
| self.err_span_(start_bpos, |
| self.last_pos, |
| "this form of character escape may only be used \ |
| with characters in the range [\\x00-\\x7f]"); |
| valid = false; |
| } |
| |
| match char::from_u32(accum_int) { |
| Some(_) => valid, |
| None => { |
| let last_bpos = self.last_pos; |
| self.err_span_(start_bpos, last_bpos, "illegal numeric character escape"); |
| false |
| } |
| } |
| } |
| |
| /// Scan for a single (possibly escaped) byte or char |
| /// in a byte, (non-raw) byte string, char, or (non-raw) string literal. |
| /// `start` is the position of `first_source_char`, which is already consumed. |
| /// |
| /// Returns true if there was a valid char/byte, false otherwise. |
| fn scan_char_or_byte(&mut self, start: BytePos, first_source_char: char, |
| ascii_only: bool, delim: char) -> bool { |
| match first_source_char { |
| '\\' => { |
| // '\X' for some X must be a character constant: |
| let escaped = self.curr; |
| let escaped_pos = self.last_pos; |
| self.bump(); |
| match escaped { |
| None => {}, // EOF here is an error that will be checked later. |
| Some(e) => { |
| return match e { |
| 'n' | 'r' | 't' | '\\' | '\'' | '"' | '0' => true, |
| 'x' => self.scan_byte_escape(delim, !ascii_only), |
| 'u' if self.curr_is('{') => { |
| let valid = self.scan_unicode_escape(delim); |
| if valid && ascii_only { |
| self.err_span_( |
| escaped_pos, |
| self.last_pos, |
| "unicode escape sequences cannot be used as a byte or in \ |
| a byte string" |
| ); |
| false |
| } else { |
| valid |
| } |
| } |
| '\n' if delim == '"' => { |
| self.consume_whitespace(); |
| true |
| }, |
| '\r' if delim == '"' && self.curr_is('\n') => { |
| self.consume_whitespace(); |
| true |
| } |
| c => { |
| let last_pos = self.last_pos; |
| self.err_span_char( |
| escaped_pos, last_pos, |
| if ascii_only { "unknown byte escape" } |
| else { "unknown character escape" }, |
| c); |
| let sp = codemap::mk_sp(escaped_pos, last_pos); |
| if e == '\r' { |
| self.span_diagnostic.span_help( |
| sp, |
| "this is an isolated carriage return; consider checking \ |
| your editor and version control settings") |
| } |
| if (e == '{' || e == '}') && !ascii_only { |
| self.span_diagnostic.span_help( |
| sp, |
| "if used in a formatting string, \ |
| curly braces are escaped with `{{` and `}}`") |
| } |
| false |
| } |
| } |
| } |
| } |
| } |
| '\t' | '\n' | '\r' | '\'' if delim == '\'' => { |
| let last_pos = self.last_pos; |
| self.err_span_char( |
| start, last_pos, |
| if ascii_only { "byte constant must be escaped" } |
| else { "character constant must be escaped" }, |
| first_source_char); |
| return false; |
| } |
| '\r' => { |
| if self.curr_is('\n') { |
| self.bump(); |
| return true; |
| } else { |
| self.err_span_(start, self.last_pos, |
| "bare CR not allowed in string, use \\r instead"); |
| return false; |
| } |
| } |
| _ => if ascii_only && first_source_char > '\x7F' { |
| let last_pos = self.last_pos; |
| self.err_span_char( |
| start, last_pos, |
| "byte constant must be ASCII. \ |
| Use a \\xHH escape for a non-ASCII byte", first_source_char); |
| return false; |
| } |
| } |
| true |
| } |
| |
| /// Scan over a \u{...} escape |
| /// |
| /// At this point, we have already seen the \ and the u, the { is the current character. We |
| /// will read at least one digit, and up to 6, and pass over the }. |
| fn scan_unicode_escape(&mut self, delim: char) -> bool { |
| self.bump(); // past the { |
| let start_bpos = self.last_pos; |
| let mut count = 0; |
| let mut accum_int = 0; |
| let mut valid = true; |
| |
| while !self.curr_is('}') && count <= 6 { |
| let c = match self.curr { |
| Some(c) => c, |
| None => { |
| self.fatal_span_(start_bpos, self.last_pos, |
| "unterminated unicode escape (found EOF)"); |
| } |
| }; |
| accum_int *= 16; |
| accum_int += c.to_digit(16).unwrap_or_else(|| { |
| if c == delim { |
| self.fatal_span_(self.last_pos, self.pos, |
| "unterminated unicode escape (needed a `}`)"); |
| } else { |
| self.err_span_char(self.last_pos, self.pos, |
| "illegal character in unicode escape", c); |
| } |
| valid = false; |
| 0 |
| }); |
| self.bump(); |
| count += 1; |
| } |
| |
| if count > 6 { |
| self.err_span_(start_bpos, self.last_pos, |
| "overlong unicode escape (can have at most 6 hex digits)"); |
| valid = false; |
| } |
| |
| self.bump(); // past the ending } |
| |
| if valid && (char::from_u32(accum_int).is_none() || count == 0) { |
| self.err_span_(start_bpos, self.last_pos, "illegal unicode character escape"); |
| valid= false; |
| } |
| |
| |
| valid |
| } |
| |
| /// Scan over a float exponent. |
| fn scan_float_exponent(&mut self) { |
| if self.curr_is('e') || self.curr_is('E') { |
| self.bump(); |
| if self.curr_is('-') || self.curr_is('+') { |
| self.bump(); |
| } |
| if self.scan_digits(10, 10) == 0 { |
| self.err_span_(self.last_pos, self.pos, "expected at least one digit in exponent") |
| } |
| } |
| } |
| |
| /// Check that a base is valid for a floating literal, emitting a nice |
| /// error if it isn't. |
| fn check_float_base(&mut self, start_bpos: BytePos, last_bpos: BytePos, base: usize) { |
| match base { |
| 16 => self.err_span_(start_bpos, last_bpos, "hexadecimal float literal is not \ |
| supported"), |
| 8 => self.err_span_(start_bpos, last_bpos, "octal float literal is not supported"), |
| 2 => self.err_span_(start_bpos, last_bpos, "binary float literal is not supported"), |
| _ => () |
| } |
| } |
| |
| fn binop(&mut self, op: token::BinOpToken) -> token::Token { |
| self.bump(); |
| if self.curr_is('=') { |
| self.bump(); |
| return token::BinOpEq(op); |
| } else { |
| return token::BinOp(op); |
| } |
| } |
| |
| /// Return the next token from the string, advances the input past that |
| /// token, and updates the interner |
| fn next_token_inner(&mut self) -> token::Token { |
| let c = self.curr; |
| if ident_start(c) && match (c.unwrap(), self.nextch(), self.nextnextch()) { |
| // Note: r as in r" or r#" is part of a raw string literal, |
| // b as in b' is part of a byte literal. |
| // They are not identifiers, and are handled further down. |
| ('r', Some('"'), _) | ('r', Some('#'), _) | |
| ('b', Some('"'), _) | ('b', Some('\''), _) | |
| ('b', Some('r'), Some('"')) | ('b', Some('r'), Some('#')) => false, |
| _ => true |
| } { |
| let start = self.last_pos; |
| while ident_continue(self.curr) { |
| self.bump(); |
| } |
| |
| return self.with_str_from(start, |string| { |
| if string == "_" { |
| token::Underscore |
| } else { |
| // FIXME: perform NFKC normalization here. (Issue #2253) |
| if self.curr_is(':') && self.nextch_is(':') { |
| token::Ident(str_to_ident(string), token::ModName) |
| } else { |
| token::Ident(str_to_ident(string), token::Plain) |
| } |
| } |
| }); |
| } |
| |
| if is_dec_digit(c) { |
| let num = self.scan_number(c.unwrap()); |
| let suffix = self.scan_optional_raw_name(); |
| debug!("next_token_inner: scanned number {:?}, {:?}", num, suffix); |
| return token::Literal(num, suffix) |
| } |
| |
| match c.expect("next_token_inner called at EOF") { |
| // One-byte tokens. |
| ';' => { self.bump(); return token::Semi; } |
| ',' => { self.bump(); return token::Comma; } |
| '.' => { |
| self.bump(); |
| return if self.curr_is('.') { |
| self.bump(); |
| if self.curr_is('.') { |
| self.bump(); |
| token::DotDotDot |
| } else { |
| token::DotDot |
| } |
| } else { |
| token::Dot |
| }; |
| } |
| '(' => { self.bump(); return token::OpenDelim(token::Paren); } |
| ')' => { self.bump(); return token::CloseDelim(token::Paren); } |
| '{' => { self.bump(); return token::OpenDelim(token::Brace); } |
| '}' => { self.bump(); return token::CloseDelim(token::Brace); } |
| '[' => { self.bump(); return token::OpenDelim(token::Bracket); } |
| ']' => { self.bump(); return token::CloseDelim(token::Bracket); } |
| '@' => { self.bump(); return token::At; } |
| '#' => { self.bump(); return token::Pound; } |
| '~' => { self.bump(); return token::Tilde; } |
| '?' => { self.bump(); return token::Question; } |
| ':' => { |
| self.bump(); |
| if self.curr_is(':') { |
| self.bump(); |
| return token::ModSep; |
| } else { |
| return token::Colon; |
| } |
| } |
| |
| '$' => { self.bump(); return token::Dollar; } |
| |
| // Multi-byte tokens. |
| '=' => { |
| self.bump(); |
| if self.curr_is('=') { |
| self.bump(); |
| return token::EqEq; |
| } else if self.curr_is('>') { |
| self.bump(); |
| return token::FatArrow; |
| } else { |
| return token::Eq; |
| } |
| } |
| '!' => { |
| self.bump(); |
| if self.curr_is('=') { |
| self.bump(); |
| return token::Ne; |
| } else { return token::Not; } |
| } |
| '<' => { |
| self.bump(); |
| match self.curr.unwrap_or('\x00') { |
| '=' => { self.bump(); return token::Le; } |
| '<' => { return self.binop(token::Shl); } |
| '-' => { |
| self.bump(); |
| match self.curr.unwrap_or('\x00') { |
| _ => { return token::LArrow; } |
| } |
| } |
| _ => { return token::Lt; } |
| } |
| } |
| '>' => { |
| self.bump(); |
| match self.curr.unwrap_or('\x00') { |
| '=' => { self.bump(); return token::Ge; } |
| '>' => { return self.binop(token::Shr); } |
| _ => { return token::Gt; } |
| } |
| } |
| '\'' => { |
| // Either a character constant 'a' OR a lifetime name 'abc |
| self.bump(); |
| let start = self.last_pos; |
| |
| // the eof will be picked up by the final `'` check below |
| let c2 = self.curr.unwrap_or('\x00'); |
| self.bump(); |
| |
| // If the character is an ident start not followed by another single |
| // quote, then this is a lifetime name: |
| if ident_start(Some(c2)) && !self.curr_is('\'') { |
| while ident_continue(self.curr) { |
| self.bump(); |
| } |
| |
| // Include the leading `'` in the real identifier, for macro |
| // expansion purposes. See #12512 for the gory details of why |
| // this is necessary. |
| let ident = self.with_str_from(start, |lifetime_name| { |
| str_to_ident(&format!("'{}", lifetime_name)) |
| }); |
| |
| // Conjure up a "keyword checking ident" to make sure that |
| // the lifetime name is not a keyword. |
| let keyword_checking_ident = |
| self.with_str_from(start, |lifetime_name| { |
| str_to_ident(lifetime_name) |
| }); |
| let keyword_checking_token = |
| &token::Ident(keyword_checking_ident, token::Plain); |
| let last_bpos = self.last_pos; |
| if keyword_checking_token.is_keyword(token::keywords::SelfValue) { |
| self.err_span_(start, |
| last_bpos, |
| "invalid lifetime name: 'self \ |
| is no longer a special lifetime"); |
| } else if keyword_checking_token.is_any_keyword() && |
| !keyword_checking_token.is_keyword(token::keywords::Static) |
| { |
| self.err_span_(start, |
| last_bpos, |
| "invalid lifetime name"); |
| } |
| return token::Lifetime(ident); |
| } |
| |
| // Otherwise it is a character constant: |
| let valid = self.scan_char_or_byte(start, c2, /* ascii_only = */ false, '\''); |
| if !self.curr_is('\'') { |
| let last_bpos = self.last_pos; |
| self.fatal_span_verbose( |
| // Byte offsetting here is okay because the |
| // character before position `start` is an |
| // ascii single quote. |
| start - BytePos(1), last_bpos, |
| "unterminated character constant".to_string()); |
| } |
| let id = if valid { self.name_from(start) } else { token::intern("0") }; |
| self.bump(); // advance curr past token |
| let suffix = self.scan_optional_raw_name(); |
| return token::Literal(token::Char(id), suffix); |
| } |
| 'b' => { |
| self.bump(); |
| let lit = match self.curr { |
| Some('\'') => self.scan_byte(), |
| Some('"') => self.scan_byte_string(), |
| Some('r') => self.scan_raw_byte_string(), |
| _ => unreachable!() // Should have been a token::Ident above. |
| }; |
| let suffix = self.scan_optional_raw_name(); |
| return token::Literal(lit, suffix); |
| } |
| '"' => { |
| let start_bpos = self.last_pos; |
| let mut valid = true; |
| self.bump(); |
| while !self.curr_is('"') { |
| if self.is_eof() { |
| let last_bpos = self.last_pos; |
| self.fatal_span_(start_bpos, last_bpos, "unterminated double quote string"); |
| } |
| |
| let ch_start = self.last_pos; |
| let ch = self.curr.unwrap(); |
| self.bump(); |
| valid &= self.scan_char_or_byte(ch_start, ch, /* ascii_only = */ false, '"'); |
| } |
| // adjust for the ASCII " at the start of the literal |
| let id = if valid { self.name_from(start_bpos + BytePos(1)) } |
| else { token::intern("??") }; |
| self.bump(); |
| let suffix = self.scan_optional_raw_name(); |
| return token::Literal(token::Str_(id), suffix); |
| } |
| 'r' => { |
| let start_bpos = self.last_pos; |
| self.bump(); |
| let mut hash_count = 0; |
| while self.curr_is('#') { |
| self.bump(); |
| hash_count += 1; |
| } |
| |
| if self.is_eof() { |
| let last_bpos = self.last_pos; |
| self.fatal_span_(start_bpos, last_bpos, "unterminated raw string"); |
| } else if !self.curr_is('"') { |
| let last_bpos = self.last_pos; |
| let curr_char = self.curr.unwrap(); |
| self.fatal_span_char(start_bpos, last_bpos, |
| "only `#` is allowed in raw string delimitation; \ |
| found illegal character", |
| curr_char); |
| } |
| self.bump(); |
| let content_start_bpos = self.last_pos; |
| let mut content_end_bpos; |
| let mut valid = true; |
| 'outer: loop { |
| if self.is_eof() { |
| let last_bpos = self.last_pos; |
| self.fatal_span_(start_bpos, last_bpos, "unterminated raw string"); |
| } |
| //if self.curr_is('"') { |
| //content_end_bpos = self.last_pos; |
| //for _ in 0..hash_count { |
| //self.bump(); |
| //if !self.curr_is('#') { |
| //continue 'outer; |
| let c = self.curr.unwrap(); |
| match c { |
| '"' => { |
| content_end_bpos = self.last_pos; |
| for _ in 0..hash_count { |
| self.bump(); |
| if !self.curr_is('#') { |
| continue 'outer; |
| } |
| } |
| break; |
| }, |
| '\r' => { |
| if !self.nextch_is('\n') { |
| let last_bpos = self.last_pos; |
| self.err_span_(start_bpos, last_bpos, "bare CR not allowed in raw \ |
| string, use \\r instead"); |
| valid = false; |
| } |
| } |
| _ => () |
| } |
| self.bump(); |
| } |
| self.bump(); |
| let id = if valid { |
| self.name_from_to(content_start_bpos, content_end_bpos) |
| } else { |
| token::intern("??") |
| }; |
| let suffix = self.scan_optional_raw_name(); |
| return token::Literal(token::StrRaw(id, hash_count), suffix); |
| } |
| '-' => { |
| if self.nextch_is('>') { |
| self.bump(); |
| self.bump(); |
| return token::RArrow; |
| } else { return self.binop(token::Minus); } |
| } |
| '&' => { |
| if self.nextch_is('&') { |
| self.bump(); |
| self.bump(); |
| return token::AndAnd; |
| } else { return self.binop(token::And); } |
| } |
| '|' => { |
| match self.nextch() { |
| Some('|') => { self.bump(); self.bump(); return token::OrOr; } |
| _ => { return self.binop(token::Or); } |
| } |
| } |
| '+' => { return self.binop(token::Plus); } |
| '*' => { return self.binop(token::Star); } |
| '/' => { return self.binop(token::Slash); } |
| '^' => { return self.binop(token::Caret); } |
| '%' => { return self.binop(token::Percent); } |
| c => { |
| let last_bpos = self.last_pos; |
| let bpos = self.pos; |
| self.fatal_span_char(last_bpos, bpos, "unknown start of token", c); |
| } |
| } |
| } |
| |
| fn consume_whitespace(&mut self) { |
| while is_whitespace(self.curr) && !self.is_eof() { self.bump(); } |
| } |
| |
| fn read_to_eol(&mut self) -> String { |
| let mut val = String::new(); |
| while !self.curr_is('\n') && !self.is_eof() { |
| val.push(self.curr.unwrap()); |
| self.bump(); |
| } |
| if self.curr_is('\n') { self.bump(); } |
| return val |
| } |
| |
| fn read_one_line_comment(&mut self) -> String { |
| let val = self.read_to_eol(); |
| assert!((val.as_bytes()[0] == b'/' && val.as_bytes()[1] == b'/') |
| || (val.as_bytes()[0] == b'#' && val.as_bytes()[1] == b'!')); |
| return val; |
| } |
| |
| fn consume_non_eol_whitespace(&mut self) { |
| while is_whitespace(self.curr) && !self.curr_is('\n') && !self.is_eof() { |
| self.bump(); |
| } |
| } |
| |
| fn peeking_at_comment(&self) -> bool { |
| (self.curr_is('/') && self.nextch_is('/')) |
| || (self.curr_is('/') && self.nextch_is('*')) |
| // consider shebangs comments, but not inner attributes |
| || (self.curr_is('#') && self.nextch_is('!') && !self.nextnextch_is('[')) |
| } |
| |
| fn scan_byte(&mut self) -> token::Lit { |
| self.bump(); |
| let start = self.last_pos; |
| |
| // the eof will be picked up by the final `'` check below |
| let c2 = self.curr.unwrap_or('\x00'); |
| self.bump(); |
| |
| let valid = self.scan_char_or_byte(start, c2, /* ascii_only = */ true, '\''); |
| if !self.curr_is('\'') { |
| // Byte offsetting here is okay because the |
| // character before position `start` are an |
| // ascii single quote and ascii 'b'. |
| let last_pos = self.last_pos; |
| self.fatal_span_verbose( |
| start - BytePos(2), last_pos, |
| "unterminated byte constant".to_string()); |
| } |
| |
| let id = if valid { self.name_from(start) } else { token::intern("?") }; |
| self.bump(); // advance curr past token |
| return token::Byte(id); |
| } |
| |
| fn scan_byte_escape(&mut self, delim: char, below_0x7f_only: bool) -> bool { |
| self.scan_hex_digits(2, delim, below_0x7f_only) |
| } |
| |
| fn scan_byte_string(&mut self) -> token::Lit { |
| self.bump(); |
| let start = self.last_pos; |
| let mut valid = true; |
| |
| while !self.curr_is('"') { |
| if self.is_eof() { |
| let last_pos = self.last_pos; |
| self.fatal_span_(start, last_pos, |
| "unterminated double quote byte string"); |
| } |
| |
| let ch_start = self.last_pos; |
| let ch = self.curr.unwrap(); |
| self.bump(); |
| valid &= self.scan_char_or_byte(ch_start, ch, /* ascii_only = */ true, '"'); |
| } |
| let id = if valid { self.name_from(start) } else { token::intern("??") }; |
| self.bump(); |
| return token::Binary(id); |
| } |
| |
| fn scan_raw_byte_string(&mut self) -> token::Lit { |
| let start_bpos = self.last_pos; |
| self.bump(); |
| let mut hash_count = 0; |
| while self.curr_is('#') { |
| self.bump(); |
| hash_count += 1; |
| } |
| |
| if self.is_eof() { |
| let last_pos = self.last_pos; |
| self.fatal_span_(start_bpos, last_pos, "unterminated raw string"); |
| } else if !self.curr_is('"') { |
| let last_pos = self.last_pos; |
| let ch = self.curr.unwrap(); |
| self.fatal_span_char(start_bpos, last_pos, |
| "only `#` is allowed in raw string delimitation; \ |
| found illegal character", |
| ch); |
| } |
| self.bump(); |
| let content_start_bpos = self.last_pos; |
| let mut content_end_bpos; |
| 'outer: loop { |
| match self.curr { |
| None => { |
| let last_pos = self.last_pos; |
| self.fatal_span_(start_bpos, last_pos, "unterminated raw string") |
| }, |
| Some('"') => { |
| content_end_bpos = self.last_pos; |
| for _ in 0..hash_count { |
| self.bump(); |
| if !self.curr_is('#') { |
| continue 'outer; |
| } |
| } |
| break; |
| }, |
| Some(c) => if c > '\x7F' { |
| let last_pos = self.last_pos; |
| self.err_span_char( |
| last_pos, last_pos, "raw byte string must be ASCII", c); |
| } |
| } |
| self.bump(); |
| } |
| self.bump(); |
| return token::BinaryRaw(self.name_from_to(content_start_bpos, |
| content_end_bpos), |
| hash_count); |
| } |
| } |
| |
| pub fn is_whitespace(c: Option<char>) -> bool { |
| match c.unwrap_or('\x00') { // None can be null for now... it's not whitespace |
| ' ' | '\n' | '\t' | '\r' => true, |
| _ => false |
| } |
| } |
| |
| fn in_range(c: Option<char>, lo: char, hi: char) -> bool { |
| match c { |
| Some(c) => lo <= c && c <= hi, |
| _ => false |
| } |
| } |
| |
| fn is_dec_digit(c: Option<char>) -> bool { return in_range(c, '0', '9'); } |
| |
| pub fn is_doc_comment(s: &str) -> bool { |
| let res = (s.starts_with("///") && *s.as_bytes().get(3).unwrap_or(&b' ') != b'/') |
| || s.starts_with("//!"); |
| debug!("is {:?} a doc comment? {}", s, res); |
| res |
| } |
| |
| pub fn is_block_doc_comment(s: &str) -> bool { |
| let res = (s.starts_with("/**") && *s.as_bytes().get(3).unwrap_or(&b' ') != b'*') |
| || s.starts_with("/*!"); |
| debug!("is {:?} a doc comment? {}", s, res); |
| res |
| } |
| |
| fn ident_start(c: Option<char>) -> bool { |
| let c = match c { Some(c) => c, None => return false }; |
| |
| (c >= 'a' && c <= 'z') |
| || (c >= 'A' && c <= 'Z') |
| || c == '_' |
| || (c > '\x7f' && c.is_xid_start()) |
| } |
| |
| fn ident_continue(c: Option<char>) -> bool { |
| let c = match c { Some(c) => c, None => return false }; |
| |
| (c >= 'a' && c <= 'z') |
| || (c >= 'A' && c <= 'Z') |
| || (c >= '0' && c <= '9') |
| || c == '_' |
| || (c > '\x7f' && c.is_xid_continue()) |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| |
| use codemap::{BytePos, CodeMap, Span, NO_EXPANSION}; |
| use diagnostic; |
| use parse::token; |
| use parse::token::{str_to_ident}; |
| use std::io; |
| |
| fn mk_sh() -> diagnostic::SpanHandler { |
| // FIXME (#22405): Replace `Box::new` with `box` here when/if possible. |
| let emitter = diagnostic::EmitterWriter::new(Box::new(io::sink()), None); |
| let handler = diagnostic::mk_handler(true, Box::new(emitter)); |
| diagnostic::mk_span_handler(handler, CodeMap::new()) |
| } |
| |
| // open a string reader for the given string |
| fn setup<'a>(span_handler: &'a diagnostic::SpanHandler, |
| teststr: String) -> StringReader<'a> { |
| let fm = span_handler.cm.new_filemap("zebra.rs".to_string(), teststr); |
| StringReader::new(span_handler, fm) |
| } |
| |
| #[test] fn t1 () { |
| let span_handler = mk_sh(); |
| let mut string_reader = setup(&span_handler, |
| "/* my source file */ \ |
| fn main() { println!(\"zebra\"); }\n".to_string()); |
| let id = str_to_ident("fn"); |
| assert_eq!(string_reader.next_token().tok, token::Comment); |
| assert_eq!(string_reader.next_token().tok, token::Whitespace); |
| let tok1 = string_reader.next_token(); |
| let tok2 = TokenAndSpan{ |
| tok:token::Ident(id, token::Plain), |
| sp:Span {lo:BytePos(21),hi:BytePos(23),expn_id: NO_EXPANSION}}; |
| assert_eq!(tok1,tok2); |
| assert_eq!(string_reader.next_token().tok, token::Whitespace); |
| // the 'main' id is already read: |
| assert_eq!(string_reader.last_pos.clone(), BytePos(28)); |
| // read another token: |
| let tok3 = string_reader.next_token(); |
| let tok4 = TokenAndSpan{ |
| tok:token::Ident(str_to_ident("main"), token::Plain), |
| sp:Span {lo:BytePos(24),hi:BytePos(28),expn_id: NO_EXPANSION}}; |
| assert_eq!(tok3,tok4); |
| // the lparen is already read: |
| assert_eq!(string_reader.last_pos.clone(), BytePos(29)) |
| } |
| |
| // check that the given reader produces the desired stream |
| // of tokens (stop checking after exhausting the expected vec) |
| fn check_tokenization (mut string_reader: StringReader, expected: Vec<token::Token> ) { |
| for expected_tok in &expected { |
| assert_eq!(&string_reader.next_token().tok, expected_tok); |
| } |
| } |
| |
| // make the identifier by looking up the string in the interner |
| fn mk_ident(id: &str, style: token::IdentStyle) -> token::Token { |
| token::Ident(str_to_ident(id), style) |
| } |
| |
| #[test] fn doublecolonparsing () { |
| check_tokenization(setup(&mk_sh(), "a b".to_string()), |
| vec![mk_ident("a", token::Plain), |
| token::Whitespace, |
| mk_ident("b", token::Plain)]); |
| } |
| |
| #[test] fn dcparsing_2 () { |
| check_tokenization(setup(&mk_sh(), "a::b".to_string()), |
| vec![mk_ident("a",token::ModName), |
| token::ModSep, |
| mk_ident("b", token::Plain)]); |
| } |
| |
| #[test] fn dcparsing_3 () { |
| check_tokenization(setup(&mk_sh(), "a ::b".to_string()), |
| vec![mk_ident("a", token::Plain), |
| token::Whitespace, |
| token::ModSep, |
| mk_ident("b", token::Plain)]); |
| } |
| |
| #[test] fn dcparsing_4 () { |
| check_tokenization(setup(&mk_sh(), "a:: b".to_string()), |
| vec![mk_ident("a",token::ModName), |
| token::ModSep, |
| token::Whitespace, |
| mk_ident("b", token::Plain)]); |
| } |
| |
| #[test] fn character_a() { |
| assert_eq!(setup(&mk_sh(), "'a'".to_string()).next_token().tok, |
| token::Literal(token::Char(token::intern("a")), None)); |
| } |
| |
| #[test] fn character_space() { |
| assert_eq!(setup(&mk_sh(), "' '".to_string()).next_token().tok, |
| token::Literal(token::Char(token::intern(" ")), None)); |
| } |
| |
| #[test] fn character_escaped() { |
| assert_eq!(setup(&mk_sh(), "'\\n'".to_string()).next_token().tok, |
| token::Literal(token::Char(token::intern("\\n")), None)); |
| } |
| |
| #[test] fn lifetime_name() { |
| assert_eq!(setup(&mk_sh(), "'abc".to_string()).next_token().tok, |
| token::Lifetime(token::str_to_ident("'abc"))); |
| } |
| |
| #[test] fn raw_string() { |
| assert_eq!(setup(&mk_sh(), |
| "r###\"\"#a\\b\x00c\"\"###".to_string()).next_token() |
| .tok, |
| token::Literal(token::StrRaw(token::intern("\"#a\\b\x00c\""), 3), None)); |
| } |
| |
| #[test] fn literal_suffixes() { |
| macro_rules! test { |
| ($input: expr, $tok_type: ident, $tok_contents: expr) => {{ |
| assert_eq!(setup(&mk_sh(), format!("{}suffix", $input)).next_token().tok, |
| token::Literal(token::$tok_type(token::intern($tok_contents)), |
| Some(token::intern("suffix")))); |
| // with a whitespace separator: |
| assert_eq!(setup(&mk_sh(), format!("{} suffix", $input)).next_token().tok, |
| token::Literal(token::$tok_type(token::intern($tok_contents)), |
| None)); |
| }} |
| } |
| |
| test!("'a'", Char, "a"); |
| test!("b'a'", Byte, "a"); |
| test!("\"a\"", Str_, "a"); |
| test!("b\"a\"", Binary, "a"); |
| test!("1234", Integer, "1234"); |
| test!("0b101", Integer, "0b101"); |
| test!("0xABC", Integer, "0xABC"); |
| test!("1.0", Float, "1.0"); |
| test!("1.0e10", Float, "1.0e10"); |
| |
| assert_eq!(setup(&mk_sh(), "2us".to_string()).next_token().tok, |
| token::Literal(token::Integer(token::intern("2")), |
| Some(token::intern("us")))); |
| assert_eq!(setup(&mk_sh(), "r###\"raw\"###suffix".to_string()).next_token().tok, |
| token::Literal(token::StrRaw(token::intern("raw"), 3), |
| Some(token::intern("suffix")))); |
| assert_eq!(setup(&mk_sh(), "br###\"raw\"###suffix".to_string()).next_token().tok, |
| token::Literal(token::BinaryRaw(token::intern("raw"), 3), |
| Some(token::intern("suffix")))); |
| } |
| |
| #[test] fn line_doc_comments() { |
| assert!(is_doc_comment("///")); |
| assert!(is_doc_comment("/// blah")); |
| assert!(!is_doc_comment("////")); |
| } |
| |
| #[test] fn nested_block_comments() { |
| let sh = mk_sh(); |
| let mut lexer = setup(&sh, "/* /* */ */'a'".to_string()); |
| match lexer.next_token().tok { |
| token::Comment => { }, |
| _ => panic!("expected a comment!") |
| } |
| assert_eq!(lexer.next_token().tok, token::Literal(token::Char(token::intern("a")), None)); |
| } |
| |
| } |
