1 // Copyright 2012-2016 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 //! `TokenStream`s represent syntactic objects before they are converted into ASTs.
14 //! A `TokenStream` is, roughly speaking, a sequence (eg stream) of `TokenTree`s,
15 //! which are themselves a single `Token` or a `Delimited` subsequence of tokens.
18 //! `TokenStreams` are persistent data structures constructed as ropes with reference
19 //! counted-children. In general, this means that calling an operation on a `TokenStream`
20 //! (such as `slice`) produces an entirely new `TokenStream` from the borrowed reference to
21 //! the original. This essentially coerces `TokenStream`s into 'views' of their subparts,
22 //! and a borrowed `TokenStream` is sufficient to build an owned `TokenStream` without taking
23 //! ownership of the original.
25 use syntax_pos::{BytePos, Span, DUMMY_SP};
27 use ext::tt::{macro_parser, quoted};
29 use parse::token::{self, Token};
31 use serialize::{Decoder, Decodable, Encoder, Encodable};
35 use std::{fmt, iter, mem};
37 /// A delimited sequence of token trees
38 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
39 pub struct Delimited {
40 /// The type of delimiter
41 pub delim: token::DelimToken,
42 /// The delimited sequence of token trees
43 pub tts: ThinTokenStream,
47 /// Returns the opening delimiter as a token.
48 pub fn open_token(&self) -> token::Token {
49 token::OpenDelim(self.delim)
52 /// Returns the closing delimiter as a token.
53 pub fn close_token(&self) -> token::Token {
54 token::CloseDelim(self.delim)
57 /// Returns the opening delimiter as a token tree.
58 pub fn open_tt(&self, span: Span) -> TokenTree {
59 let open_span = if span.is_dummy() {
62 span.with_hi(span.lo() + BytePos(self.delim.len() as u32))
64 TokenTree::Token(open_span, self.open_token())
67 /// Returns the closing delimiter as a token tree.
68 pub fn close_tt(&self, span: Span) -> TokenTree {
69 let close_span = if span.is_dummy() {
72 span.with_lo(span.hi() - BytePos(self.delim.len() as u32))
74 TokenTree::Token(close_span, self.close_token())
77 /// Returns the token trees inside the delimiters.
78 pub fn stream(&self) -> TokenStream {
79 self.tts.clone().into()
83 /// When the main rust parser encounters a syntax-extension invocation, it
84 /// parses the arguments to the invocation as a token-tree. This is a very
85 /// loose structure, such that all sorts of different AST-fragments can
86 /// be passed to syntax extensions using a uniform type.
88 /// If the syntax extension is an MBE macro, it will attempt to match its
89 /// LHS token tree against the provided token tree, and if it finds a
90 /// match, will transcribe the RHS token tree, splicing in any captured
91 /// `macro_parser::matched_nonterminals` into the `SubstNt`s it finds.
93 /// The RHS of an MBE macro is the only place `SubstNt`s are substituted.
94 /// Nothing special happens to misnamed or misplaced `SubstNt`s.
95 #[derive(Debug, Clone, PartialEq, RustcEncodable, RustcDecodable)]
98 Token(Span, token::Token),
99 /// A delimited sequence of token trees
100 Delimited(Span, Delimited),
104 /// Use this token tree as a matcher to parse given tts.
105 pub fn parse(cx: &base::ExtCtxt, mtch: &[quoted::TokenTree], tts: TokenStream)
106 -> macro_parser::NamedParseResult {
107 // `None` is because we're not interpolating
108 let directory = Directory {
109 path: Cow::from(cx.current_expansion.module.directory.as_path()),
110 ownership: cx.current_expansion.directory_ownership,
112 macro_parser::parse(cx.parse_sess(), tts, mtch, Some(directory), true)
115 /// Check if this TokenTree is equal to the other, regardless of span information.
116 pub fn eq_unspanned(&self, other: &TokenTree) -> bool {
117 match (self, other) {
118 (&TokenTree::Token(_, ref tk), &TokenTree::Token(_, ref tk2)) => tk == tk2,
119 (&TokenTree::Delimited(_, ref dl), &TokenTree::Delimited(_, ref dl2)) => {
120 dl.delim == dl2.delim &&
121 dl.stream().eq_unspanned(&dl2.stream())
127 // See comments in `interpolated_to_tokenstream` for why we care about
128 // *probably* equal here rather than actual equality
130 // This is otherwise the same as `eq_unspanned`, only recursing with a
132 pub fn probably_equal_for_proc_macro(&self, other: &TokenTree) -> bool {
133 match (self, other) {
134 (&TokenTree::Token(_, ref tk), &TokenTree::Token(_, ref tk2)) => {
135 tk.probably_equal_for_proc_macro(tk2)
137 (&TokenTree::Delimited(_, ref dl), &TokenTree::Delimited(_, ref dl2)) => {
138 dl.delim == dl2.delim &&
139 dl.stream().probably_equal_for_proc_macro(&dl2.stream())
145 /// Retrieve the TokenTree's span.
146 pub fn span(&self) -> Span {
148 TokenTree::Token(sp, _) | TokenTree::Delimited(sp, _) => sp,
152 /// Modify the `TokenTree`'s span inplace.
153 pub fn set_span(&mut self, span: Span) {
155 TokenTree::Token(ref mut sp, _) | TokenTree::Delimited(ref mut sp, _) => {
161 /// Indicates if the stream is a token that is equal to the provided token.
162 pub fn eq_token(&self, t: Token) -> bool {
164 TokenTree::Token(_, ref tk) => *tk == t,
169 pub fn joint(self) -> TokenStream {
170 TokenStream { kind: TokenStreamKind::JointTree(self) }
176 /// A `TokenStream` is an abstract sequence of tokens, organized into `TokenTree`s.
177 /// The goal is for procedural macros to work with `TokenStream`s and `TokenTree`s
178 /// instead of a representation of the abstract syntax tree.
179 /// Today's `TokenTree`s can still contain AST via `Token::Interpolated` for back-compat.
180 #[derive(Clone, Debug)]
181 pub struct TokenStream {
182 kind: TokenStreamKind,
186 /// Given a `TokenStream` with a `Stream` of only two arguments, return a new `TokenStream`
187 /// separating the two arguments with a comma for diagnostic suggestions.
188 pub(crate) fn add_comma(&self) -> Option<(TokenStream, Span)> {
189 // Used to suggest if a user writes `foo!(a b);`
190 if let TokenStreamKind::Stream(ref slice) = self.kind {
191 let mut suggestion = None;
192 let mut iter = slice.iter().enumerate().peekable();
193 while let Some((pos, ts)) = iter.next() {
194 if let Some((_, next)) = iter.peek() {
197 kind: TokenStreamKind::Tree(TokenTree::Token(_, token::Token::Comma))
200 kind: TokenStreamKind::Tree(TokenTree::Token(_, token::Token::Comma))
203 kind: TokenStreamKind::Tree(TokenTree::Token(sp, _))
206 kind: TokenStreamKind::Tree(TokenTree::Delimited(sp, _))
208 let sp = sp.shrink_to_hi();
209 let comma = TokenStream {
210 kind: TokenStreamKind::Tree(TokenTree::Token(sp, token::Comma)),
212 suggestion = Some((pos, comma, sp));
218 if let Some((pos, comma, sp)) = suggestion {
219 let mut new_slice = vec![];
220 let parts = slice.split_at(pos + 1);
221 new_slice.extend_from_slice(parts.0);
222 new_slice.push(comma);
223 new_slice.extend_from_slice(parts.1);
224 let slice = RcVec::new(new_slice);
225 return Some((TokenStream { kind: TokenStreamKind::Stream(slice) }, sp));
232 #[derive(Clone, Debug)]
233 enum TokenStreamKind {
236 JointTree(TokenTree),
237 Stream(RcVec<TokenStream>),
240 impl From<TokenTree> for TokenStream {
241 fn from(tt: TokenTree) -> TokenStream {
242 TokenStream { kind: TokenStreamKind::Tree(tt) }
246 impl From<Token> for TokenStream {
247 fn from(token: Token) -> TokenStream {
248 TokenTree::Token(DUMMY_SP, token).into()
252 impl<T: Into<TokenStream>> iter::FromIterator<T> for TokenStream {
253 fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
254 TokenStream::concat(iter.into_iter().map(Into::into).collect::<Vec<_>>())
258 impl Extend<TokenStream> for TokenStream {
259 fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, iter: I) {
260 let iter = iter.into_iter();
261 let kind = mem::replace(&mut self.kind, TokenStreamKind::Empty);
263 // Vector of token streams originally in self.
264 let tts: Vec<TokenStream> = match kind {
265 TokenStreamKind::Empty => {
266 let mut vec = Vec::new();
267 vec.reserve(iter.size_hint().0);
270 TokenStreamKind::Tree(_) | TokenStreamKind::JointTree(_) => {
271 let mut vec = Vec::new();
272 vec.reserve(1 + iter.size_hint().0);
273 vec.push(TokenStream { kind });
276 TokenStreamKind::Stream(rc_vec) => match RcVec::try_unwrap(rc_vec) {
278 // Extend in place using the existing capacity if possible.
279 // This is the fast path for libraries like `quote` that
280 // build a token stream.
281 vec.reserve(iter.size_hint().0);
285 // Self is shared so we need to copy and extend that.
286 let mut vec = Vec::new();
287 vec.reserve(rc_vec.len() + iter.size_hint().0);
288 vec.extend_from_slice(&rc_vec);
294 // Perform the extend, joining tokens as needed along the way.
295 let mut builder = TokenStreamBuilder(tts);
297 builder.push(stream);
300 // Build the resulting token stream. If it contains more than one token,
301 // preserve capacity in the vector in anticipation of the caller
302 // performing additional calls to extend.
303 let mut tts = builder.0;
304 *self = match tts.len() {
305 0 => TokenStream::empty(),
306 1 => tts.pop().unwrap(),
307 _ => TokenStream::concat_rc_vec(RcVec::new_preserving_capacity(tts)),
312 impl Eq for TokenStream {}
314 impl PartialEq<TokenStream> for TokenStream {
315 fn eq(&self, other: &TokenStream) -> bool {
316 self.trees().eq(other.trees())
321 pub fn len(&self) -> usize {
322 if let TokenStreamKind::Stream(ref slice) = self.kind {
329 pub fn empty() -> TokenStream {
330 TokenStream { kind: TokenStreamKind::Empty }
333 pub fn is_empty(&self) -> bool {
335 TokenStreamKind::Empty => true,
340 pub fn concat(mut streams: Vec<TokenStream>) -> TokenStream {
341 match streams.len() {
342 0 => TokenStream::empty(),
343 1 => streams.pop().unwrap(),
344 _ => TokenStream::concat_rc_vec(RcVec::new(streams)),
348 fn concat_rc_vec(streams: RcVec<TokenStream>) -> TokenStream {
349 TokenStream { kind: TokenStreamKind::Stream(streams) }
352 pub fn trees(&self) -> Cursor {
353 self.clone().into_trees()
356 pub fn into_trees(self) -> Cursor {
360 /// Compares two TokenStreams, checking equality without regarding span information.
361 pub fn eq_unspanned(&self, other: &TokenStream) -> bool {
362 let mut t1 = self.trees();
363 let mut t2 = other.trees();
364 for (t1, t2) in t1.by_ref().zip(t2.by_ref()) {
365 if !t1.eq_unspanned(&t2) {
369 t1.next().is_none() && t2.next().is_none()
372 // See comments in `interpolated_to_tokenstream` for why we care about
373 // *probably* equal here rather than actual equality
375 // This is otherwise the same as `eq_unspanned`, only recursing with a
377 pub fn probably_equal_for_proc_macro(&self, other: &TokenStream) -> bool {
378 let mut t1 = self.trees();
379 let mut t2 = other.trees();
380 for (t1, t2) in t1.by_ref().zip(t2.by_ref()) {
381 if !t1.probably_equal_for_proc_macro(&t2) {
385 t1.next().is_none() && t2.next().is_none()
388 /// Precondition: `self` consists of a single token tree.
389 /// Returns true if the token tree is a joint operation w.r.t. `proc_macro::TokenNode`.
390 pub fn as_tree(self) -> (TokenTree, bool /* joint? */) {
392 TokenStreamKind::Tree(tree) => (tree, false),
393 TokenStreamKind::JointTree(tree) => (tree, true),
398 pub fn map_enumerated<F: FnMut(usize, TokenTree) -> TokenTree>(self, mut f: F) -> TokenStream {
399 let mut trees = self.into_trees();
400 let mut result = Vec::new();
402 while let Some(stream) = trees.next_as_stream() {
403 result.push(match stream.kind {
404 TokenStreamKind::Tree(tree) => f(i, tree).into(),
405 TokenStreamKind::JointTree(tree) => f(i, tree).joint(),
410 TokenStream::concat(result)
413 pub fn map<F: FnMut(TokenTree) -> TokenTree>(self, mut f: F) -> TokenStream {
414 let mut trees = self.into_trees();
415 let mut result = Vec::new();
416 while let Some(stream) = trees.next_as_stream() {
417 result.push(match stream.kind {
418 TokenStreamKind::Tree(tree) => f(tree).into(),
419 TokenStreamKind::JointTree(tree) => f(tree).joint(),
423 TokenStream::concat(result)
426 fn first_tree_and_joint(&self) -> Option<(TokenTree, bool)> {
428 TokenStreamKind::Empty => None,
429 TokenStreamKind::Tree(ref tree) => Some((tree.clone(), false)),
430 TokenStreamKind::JointTree(ref tree) => Some((tree.clone(), true)),
431 TokenStreamKind::Stream(ref stream) => stream.first().unwrap().first_tree_and_joint(),
435 fn last_tree_if_joint(&self) -> Option<TokenTree> {
437 TokenStreamKind::Empty | TokenStreamKind::Tree(..) => None,
438 TokenStreamKind::JointTree(ref tree) => Some(tree.clone()),
439 TokenStreamKind::Stream(ref stream) => stream.last().unwrap().last_tree_if_joint(),
445 pub struct TokenStreamBuilder(Vec<TokenStream>);
447 impl TokenStreamBuilder {
448 pub fn new() -> TokenStreamBuilder {
449 TokenStreamBuilder(Vec::new())
452 pub fn push<T: Into<TokenStream>>(&mut self, stream: T) {
453 let stream = stream.into();
454 let last_tree_if_joint = self.0.last().and_then(TokenStream::last_tree_if_joint);
455 if let Some(TokenTree::Token(last_span, last_tok)) = last_tree_if_joint {
456 if let Some((TokenTree::Token(span, tok), is_joint)) = stream.first_tree_and_joint() {
457 if let Some(glued_tok) = last_tok.glue(tok) {
458 let last_stream = self.0.pop().unwrap();
459 self.push_all_but_last_tree(&last_stream);
460 let glued_span = last_span.to(span);
461 let glued_tt = TokenTree::Token(glued_span, glued_tok);
462 let glued_tokenstream = if is_joint {
467 self.0.push(glued_tokenstream);
468 self.push_all_but_first_tree(&stream);
476 pub fn add<T: Into<TokenStream>>(mut self, stream: T) -> Self {
481 pub fn build(self) -> TokenStream {
482 TokenStream::concat(self.0)
485 fn push_all_but_last_tree(&mut self, stream: &TokenStream) {
486 if let TokenStreamKind::Stream(ref streams) = stream.kind {
487 let len = streams.len();
490 2 => self.0.push(streams[0].clone().into()),
491 _ => self.0.push(TokenStream::concat_rc_vec(streams.sub_slice(0 .. len - 1))),
493 self.push_all_but_last_tree(&streams[len - 1])
497 fn push_all_but_first_tree(&mut self, stream: &TokenStream) {
498 if let TokenStreamKind::Stream(ref streams) = stream.kind {
499 let len = streams.len();
502 2 => self.0.push(streams[1].clone().into()),
503 _ => self.0.push(TokenStream::concat_rc_vec(streams.sub_slice(1 .. len))),
505 self.push_all_but_first_tree(&streams[0])
511 pub struct Cursor(CursorKind);
516 Tree(TokenTree, bool /* consumed? */),
517 JointTree(TokenTree, bool /* consumed? */),
518 Stream(StreamCursor),
522 struct StreamCursor {
523 stream: RcVec<TokenStream>,
525 stack: Vec<(RcVec<TokenStream>, usize)>,
529 fn new(stream: RcVec<TokenStream>) -> Self {
530 StreamCursor { stream: stream, index: 0, stack: Vec::new() }
533 fn next_as_stream(&mut self) -> Option<TokenStream> {
535 if self.index < self.stream.len() {
537 let next = self.stream[self.index - 1].clone();
539 TokenStreamKind::Tree(..) | TokenStreamKind::JointTree(..) => return Some(next),
540 TokenStreamKind::Stream(stream) => self.insert(stream),
541 TokenStreamKind::Empty => {}
543 } else if let Some((stream, index)) = self.stack.pop() {
544 self.stream = stream;
552 fn insert(&mut self, stream: RcVec<TokenStream>) {
553 self.stack.push((mem::replace(&mut self.stream, stream),
554 mem::replace(&mut self.index, 0)));
558 impl Iterator for Cursor {
559 type Item = TokenTree;
561 fn next(&mut self) -> Option<TokenTree> {
562 self.next_as_stream().map(|stream| match stream.kind {
563 TokenStreamKind::Tree(tree) | TokenStreamKind::JointTree(tree) => tree,
570 fn new(stream: TokenStream) -> Self {
571 Cursor(match stream.kind {
572 TokenStreamKind::Empty => CursorKind::Empty,
573 TokenStreamKind::Tree(tree) => CursorKind::Tree(tree, false),
574 TokenStreamKind::JointTree(tree) => CursorKind::JointTree(tree, false),
575 TokenStreamKind::Stream(stream) => CursorKind::Stream(StreamCursor::new(stream)),
579 pub fn next_as_stream(&mut self) -> Option<TokenStream> {
580 let (stream, consumed) = match self.0 {
581 CursorKind::Tree(ref tree, ref mut consumed @ false) =>
582 (tree.clone().into(), consumed),
583 CursorKind::JointTree(ref tree, ref mut consumed @ false) =>
584 (tree.clone().joint(), consumed),
585 CursorKind::Stream(ref mut cursor) => return cursor.next_as_stream(),
593 pub fn insert(&mut self, stream: TokenStream) {
595 _ if stream.is_empty() => return,
596 CursorKind::Empty => *self = stream.trees(),
597 CursorKind::Tree(_, consumed) | CursorKind::JointTree(_, consumed) => {
598 *self = TokenStream::concat(vec![self.original_stream(), stream]).trees();
603 CursorKind::Stream(ref mut cursor) => {
604 cursor.insert(ThinTokenStream::from(stream).0.unwrap());
609 pub fn original_stream(&self) -> TokenStream {
611 CursorKind::Empty => TokenStream::empty(),
612 CursorKind::Tree(ref tree, _) => tree.clone().into(),
613 CursorKind::JointTree(ref tree, _) => tree.clone().joint(),
614 CursorKind::Stream(ref cursor) => TokenStream::concat_rc_vec({
615 cursor.stack.get(0).cloned().map(|(stream, _)| stream)
616 .unwrap_or(cursor.stream.clone())
621 pub fn look_ahead(&self, n: usize) -> Option<TokenTree> {
622 fn look_ahead(streams: &[TokenStream], mut n: usize) -> Result<TokenTree, usize> {
623 for stream in streams {
624 n = match stream.kind {
625 TokenStreamKind::Tree(ref tree) | TokenStreamKind::JointTree(ref tree)
626 if n == 0 => return Ok(tree.clone()),
627 TokenStreamKind::Tree(..) | TokenStreamKind::JointTree(..) => n - 1,
628 TokenStreamKind::Stream(ref stream) => match look_ahead(stream, n) {
629 Ok(tree) => return Ok(tree),
640 CursorKind::Tree(_, true) |
641 CursorKind::JointTree(_, true) => Err(n),
642 CursorKind::Tree(ref tree, false) |
643 CursorKind::JointTree(ref tree, false) => look_ahead(&[tree.clone().into()], n),
644 CursorKind::Stream(ref cursor) => {
645 look_ahead(&cursor.stream[cursor.index ..], n).or_else(|mut n| {
646 for &(ref stream, index) in cursor.stack.iter().rev() {
647 n = match look_ahead(&stream[index..], n) {
648 Ok(tree) => return Ok(tree),
660 /// The `TokenStream` type is large enough to represent a single `TokenTree` without allocation.
661 /// `ThinTokenStream` is smaller, but needs to allocate to represent a single `TokenTree`.
662 /// We must use `ThinTokenStream` in `TokenTree::Delimited` to avoid infinite size due to recursion.
663 #[derive(Debug, Clone)]
664 pub struct ThinTokenStream(Option<RcVec<TokenStream>>);
666 impl From<TokenStream> for ThinTokenStream {
667 fn from(stream: TokenStream) -> ThinTokenStream {
668 ThinTokenStream(match stream.kind {
669 TokenStreamKind::Empty => None,
670 TokenStreamKind::Tree(tree) => Some(RcVec::new(vec![tree.into()])),
671 TokenStreamKind::JointTree(tree) => Some(RcVec::new(vec![tree.joint()])),
672 TokenStreamKind::Stream(stream) => Some(stream),
677 impl From<ThinTokenStream> for TokenStream {
678 fn from(stream: ThinTokenStream) -> TokenStream {
679 stream.0.map(TokenStream::concat_rc_vec).unwrap_or_else(TokenStream::empty)
683 impl Eq for ThinTokenStream {}
685 impl PartialEq<ThinTokenStream> for ThinTokenStream {
686 fn eq(&self, other: &ThinTokenStream) -> bool {
687 TokenStream::from(self.clone()) == TokenStream::from(other.clone())
691 impl fmt::Display for TokenStream {
692 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
693 f.write_str(&pprust::tokens_to_string(self.clone()))
697 impl Encodable for TokenStream {
698 fn encode<E: Encoder>(&self, encoder: &mut E) -> Result<(), E::Error> {
699 self.trees().collect::<Vec<_>>().encode(encoder)
703 impl Decodable for TokenStream {
704 fn decode<D: Decoder>(decoder: &mut D) -> Result<TokenStream, D::Error> {
705 Vec::<TokenTree>::decode(decoder).map(|vec| vec.into_iter().collect())
709 impl Encodable for ThinTokenStream {
710 fn encode<E: Encoder>(&self, encoder: &mut E) -> Result<(), E::Error> {
711 TokenStream::from(self.clone()).encode(encoder)
715 impl Decodable for ThinTokenStream {
716 fn decode<D: Decoder>(decoder: &mut D) -> Result<ThinTokenStream, D::Error> {
717 TokenStream::decode(decoder).map(Into::into)
724 use syntax::ast::Ident;
726 use syntax_pos::{Span, BytePos, NO_EXPANSION};
727 use parse::token::Token;
728 use util::parser_testing::string_to_stream;
730 fn string_to_ts(string: &str) -> TokenStream {
731 string_to_stream(string.to_owned())
734 fn sp(a: u32, b: u32) -> Span {
735 Span::new(BytePos(a), BytePos(b), NO_EXPANSION)
741 let test_res = string_to_ts("foo::bar::baz");
742 let test_fst = string_to_ts("foo::bar");
743 let test_snd = string_to_ts("::baz");
744 let eq_res = TokenStream::concat(vec![test_fst, test_snd]);
745 assert_eq!(test_res.trees().count(), 5);
746 assert_eq!(eq_res.trees().count(), 5);
747 assert_eq!(test_res.eq_unspanned(&eq_res), true);
752 fn test_to_from_bijection() {
754 let test_start = string_to_ts("foo::bar(baz)");
755 let test_end = test_start.trees().collect();
756 assert_eq!(test_start, test_end)
763 let test_res = string_to_ts("foo");
764 let test_eqs = string_to_ts("foo");
765 assert_eq!(test_res, test_eqs)
772 let test_res = string_to_ts("::bar::baz");
773 let test_eqs = string_to_ts("::bar::baz");
774 assert_eq!(test_res, test_eqs)
781 let test_res = string_to_ts("");
782 let test_eqs = string_to_ts("");
783 assert_eq!(test_res, test_eqs)
790 let test_res = string_to_ts("::bar::baz");
791 let test_eqs = string_to_ts("bar::baz");
792 assert_eq!(test_res == test_eqs, false)
799 let test_res = string_to_ts("(bar,baz)");
800 let test_eqs = string_to_ts("bar,baz");
801 assert_eq!(test_res == test_eqs, false)
808 let test0: TokenStream = Vec::<TokenTree>::new().into_iter().collect();
809 let test1: TokenStream =
810 TokenTree::Token(sp(0, 1), Token::Ident(Ident::from_str("a"), false)).into();
811 let test2 = string_to_ts("foo(bar::baz)");
813 assert_eq!(test0.is_empty(), true);
814 assert_eq!(test1.is_empty(), false);
815 assert_eq!(test2.is_empty(), false);
820 fn test_dotdotdot() {
821 let mut builder = TokenStreamBuilder::new();
822 builder.push(TokenTree::Token(sp(0, 1), Token::Dot).joint());
823 builder.push(TokenTree::Token(sp(1, 2), Token::Dot).joint());
824 builder.push(TokenTree::Token(sp(2, 3), Token::Dot));
825 let stream = builder.build();
826 assert!(stream.eq_unspanned(&string_to_ts("...")));
827 assert_eq!(stream.trees().count(), 1);
831 fn test_extend_empty() {
833 // Append a token onto an empty token stream.
834 let mut stream = TokenStream::empty();
835 stream.extend(vec![string_to_ts("t")]);
837 let expected = string_to_ts("t");
838 assert!(stream.eq_unspanned(&expected));
843 fn test_extend_nothing() {
845 // Append nothing onto a token stream containing one token.
846 let mut stream = string_to_ts("t");
847 stream.extend(vec![]);
849 let expected = string_to_ts("t");
850 assert!(stream.eq_unspanned(&expected));
855 fn test_extend_single() {
857 // Append a token onto token stream containing a single token.
858 let mut stream = string_to_ts("t1");
859 stream.extend(vec![string_to_ts("t2")]);
861 let expected = string_to_ts("t1 t2");
862 assert!(stream.eq_unspanned(&expected));
867 fn test_extend_in_place() {
869 // Append a token onto token stream containing a reference counted
870 // vec of tokens. The token stream has a reference count of 1 so
871 // this can happen in place.
872 let mut stream = string_to_ts("t1 t2");
873 stream.extend(vec![string_to_ts("t3")]);
875 let expected = string_to_ts("t1 t2 t3");
876 assert!(stream.eq_unspanned(&expected));
881 fn test_extend_copy() {
883 // Append a token onto token stream containing a reference counted
884 // vec of tokens. The token stream is shared so the extend takes
886 let mut stream = string_to_ts("t1 t2");
887 let _incref = stream.clone();
888 stream.extend(vec![string_to_ts("t3")]);
890 let expected = string_to_ts("t1 t2 t3");
891 assert!(stream.eq_unspanned(&expected));
896 fn test_extend_no_join() {
898 let first = TokenTree::Token(DUMMY_SP, Token::Dot);
899 let second = TokenTree::Token(DUMMY_SP, Token::Dot);
901 // Append a dot onto a token stream containing a dot, but do not
903 let mut stream = TokenStream::from(first);
904 stream.extend(vec![TokenStream::from(second)]);
906 let expected = string_to_ts(". .");
907 assert!(stream.eq_unspanned(&expected));
909 let unexpected = string_to_ts("..");
910 assert!(!stream.eq_unspanned(&unexpected));
915 fn test_extend_join() {
917 let first = TokenTree::Token(DUMMY_SP, Token::Dot).joint();
918 let second = TokenTree::Token(DUMMY_SP, Token::Dot);
920 // Append a dot onto a token stream containing a dot, forming a
922 let mut stream = first;
923 stream.extend(vec![TokenStream::from(second)]);
925 let expected = string_to_ts("..");
926 assert!(stream.eq_unspanned(&expected));
928 let unexpected = string_to_ts(". .");
929 assert!(!stream.eq_unspanned(&unexpected));