1 //! FIXME: write short doc here
3 use parser::{FragmentKind, ParseError, TreeSink};
4 use rustc_hash::FxHashMap;
6 ast::{self, make::tokens::doc_comment},
7 tokenize, AstToken, Parse, SmolStr, SyntaxKind,
9 SyntaxNode, SyntaxToken, SyntaxTreeBuilder, TextRange, TextSize, Token as RawToken, T,
11 use tt::buffer::{Cursor, TokenBuffer};
13 use crate::ExpandError;
14 use crate::{subtree_source::SubtreeTokenSource, tt_iter::TtIter};
16 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
17 pub enum TokenTextRange {
23 pub fn by_kind(self, kind: SyntaxKind) -> Option<TextRange> {
25 TokenTextRange::Token(it) => Some(it),
26 TokenTextRange::Delimiter(it) => match kind {
27 T!['{'] | T!['('] | T!['['] => Some(TextRange::at(it.start(), 1.into())),
28 T!['}'] | T![')'] | T![']'] => {
29 Some(TextRange::at(it.end() - TextSize::of('}'), 1.into()))
37 /// Maps `tt::TokenId` to the relative range of the original token.
38 #[derive(Debug, PartialEq, Eq, Clone, Default)]
40 /// Maps `tt::TokenId` to the *relative* source range.
41 entries: Vec<(tt::TokenId, TokenTextRange)>,
44 /// Convert the syntax tree (what user has written) to a `TokenTree` (what macro
46 pub fn ast_to_token_tree(ast: &impl ast::AstNode) -> Option<(tt::Subtree, TokenMap)> {
47 syntax_node_to_token_tree(ast.syntax())
50 /// Convert the syntax node to a `TokenTree` (what macro
52 pub fn syntax_node_to_token_tree(node: &SyntaxNode) -> Option<(tt::Subtree, TokenMap)> {
53 let global_offset = node.text_range().start();
54 let mut c = Convertor::new(node, global_offset);
55 let subtree = c.go()?;
56 c.id_alloc.map.entries.shrink_to_fit();
57 Some((subtree, c.id_alloc.map))
60 // The following items are what `rustc` macro can be parsed into :
61 // link: https://github.com/rust-lang/rust/blob/9ebf47851a357faa4cd97f4b1dc7835f6376e639/src/libsyntax/ext/expand.rs#L141
62 // * Expr(P<ast::Expr>) -> token_tree_to_expr
63 // * Pat(P<ast::Pat>) -> token_tree_to_pat
64 // * Ty(P<ast::Ty>) -> token_tree_to_ty
65 // * Stmts(SmallVec<[ast::Stmt; 1]>) -> token_tree_to_stmts
66 // * Items(SmallVec<[P<ast::Item>; 1]>) -> token_tree_to_items
68 // * TraitItems(SmallVec<[ast::TraitItem; 1]>)
69 // * AssocItems(SmallVec<[ast::AssocItem; 1]>)
70 // * ForeignItems(SmallVec<[ast::ForeignItem; 1]>
72 pub fn token_tree_to_syntax_node(
74 fragment_kind: FragmentKind,
75 ) -> Result<(Parse<SyntaxNode>, TokenMap), ExpandError> {
76 let buffer = match tt {
77 tt::Subtree { delimiter: None, token_trees } => {
78 TokenBuffer::from_tokens(token_trees.as_slice())
80 _ => TokenBuffer::from_subtree(tt),
82 let mut token_source = SubtreeTokenSource::new(&buffer);
83 let mut tree_sink = TtTreeSink::new(buffer.begin());
84 parser::parse_fragment(&mut token_source, &mut tree_sink, fragment_kind);
85 if tree_sink.roots.len() != 1 {
86 return Err(ExpandError::ConversionError);
88 //FIXME: would be cool to report errors
89 let (parse, range_map) = tree_sink.finish();
90 Ok((parse, range_map))
93 /// Convert a string to a `TokenTree`
94 pub fn parse_to_token_tree(text: &str) -> Option<(tt::Subtree, TokenMap)> {
95 let (tokens, errors) = tokenize(text);
96 if !errors.is_empty() {
100 let mut conv = RawConvertor {
102 offset: TextSize::default(),
103 inner: tokens.iter(),
104 id_alloc: TokenIdAlloc {
105 map: Default::default(),
106 global_offset: TextSize::default(),
111 let subtree = conv.go()?;
112 Some((subtree, conv.id_alloc.map))
115 /// Split token tree with seperate expr: $($e:expr)SEP*
116 pub fn parse_exprs_with_sep(tt: &tt::Subtree, sep: char) -> Vec<tt::Subtree> {
117 if tt.token_trees.is_empty() {
121 let mut iter = TtIter::new(tt);
122 let mut res = Vec::new();
124 while iter.peek_n(0).is_some() {
125 let expanded = iter.expect_fragment(FragmentKind::Expr);
126 if expanded.err.is_some() {
130 res.push(match expanded.value {
132 Some(tt @ tt::TokenTree::Leaf(_)) => {
133 tt::Subtree { delimiter: None, token_trees: vec![tt] }
135 Some(tt::TokenTree::Subtree(tt)) => tt,
138 let mut fork = iter.clone();
139 if fork.expect_char(sep).is_err() {
145 if iter.peek_n(0).is_some() {
146 res.push(tt::Subtree { delimiter: None, token_trees: iter.into_iter().cloned().collect() });
153 pub fn token_by_range(&self, relative_range: TextRange) -> Option<tt::TokenId> {
154 let &(token_id, _) = self.entries.iter().find(|(_, range)| match range {
155 TokenTextRange::Token(it) => *it == relative_range,
156 TokenTextRange::Delimiter(it) => {
157 let open = TextRange::at(it.start(), 1.into());
158 let close = TextRange::at(it.end() - TextSize::of('}'), 1.into());
159 open == relative_range || close == relative_range
165 pub fn range_by_token(&self, token_id: tt::TokenId) -> Option<TokenTextRange> {
166 let &(_, range) = self.entries.iter().find(|(tid, _)| *tid == token_id)?;
170 fn insert(&mut self, token_id: tt::TokenId, relative_range: TextRange) {
171 self.entries.push((token_id, TokenTextRange::Token(relative_range)));
176 token_id: tt::TokenId,
177 open_relative_range: TextRange,
178 close_relative_range: TextRange,
180 let res = self.entries.len();
181 let cover = open_relative_range.cover(close_relative_range);
183 self.entries.push((token_id, TokenTextRange::Delimiter(cover)));
187 fn update_close_delim(&mut self, idx: usize, close_relative_range: TextRange) {
188 let (_, token_text_range) = &mut self.entries[idx];
189 if let TokenTextRange::Delimiter(dim) = token_text_range {
190 let cover = dim.cover(close_relative_range);
191 *token_text_range = TokenTextRange::Delimiter(cover);
195 fn remove_delim(&mut self, idx: usize) {
196 // FIXME: This could be accidentally quadratic
197 self.entries.remove(idx);
201 /// Returns the textual content of a doc comment block as a quoted string
202 /// That is, strips leading `///` (or `/**`, etc)
203 /// and strips the ending `*/`
204 /// And then quote the string, which is needed to convert to `tt::Literal`
205 fn doc_comment_text(comment: &ast::Comment) -> SmolStr {
206 let prefix_len = comment.prefix().len();
207 let mut text = &comment.text()[prefix_len..];
209 // Remove ending "*/"
210 if comment.kind().shape == ast::CommentShape::Block {
211 text = &text[0..text.len() - 2];
215 // Note that `tt::Literal` expect an escaped string
216 let text = format!("{:?}", text.escape_debug().to_string());
220 fn convert_doc_comment(token: &syntax::SyntaxToken) -> Option<Vec<tt::TokenTree>> {
221 let comment = ast::Comment::cast(token.clone())?;
222 let doc = comment.kind().doc?;
224 // Make `doc="\" Comments\""
225 let meta_tkns = vec![mk_ident("doc"), mk_punct('='), mk_doc_literal(&comment)];
228 let mut token_trees = vec![mk_punct('#')];
229 if let ast::CommentPlacement::Inner = doc {
230 token_trees.push(mk_punct('!'));
232 token_trees.push(tt::TokenTree::from(tt::Subtree {
233 delimiter: Some(tt::Delimiter {
234 kind: tt::DelimiterKind::Bracket,
235 id: tt::TokenId::unspecified(),
237 token_trees: meta_tkns,
240 return Some(token_trees);
243 fn mk_ident(s: &str) -> tt::TokenTree {
244 tt::TokenTree::from(tt::Leaf::from(tt::Ident {
246 id: tt::TokenId::unspecified(),
250 fn mk_punct(c: char) -> tt::TokenTree {
251 tt::TokenTree::from(tt::Leaf::from(tt::Punct {
253 spacing: tt::Spacing::Alone,
254 id: tt::TokenId::unspecified(),
258 fn mk_doc_literal(comment: &ast::Comment) -> tt::TokenTree {
259 let lit = tt::Literal { text: doc_comment_text(comment), id: tt::TokenId::unspecified() };
261 tt::TokenTree::from(tt::Leaf::from(lit))
265 struct TokenIdAlloc {
267 global_offset: TextSize,
272 fn alloc(&mut self, absolute_range: TextRange) -> tt::TokenId {
273 let relative_range = absolute_range - self.global_offset;
274 let token_id = tt::TokenId(self.next_id);
276 self.map.insert(token_id, relative_range);
280 fn open_delim(&mut self, open_abs_range: TextRange) -> (tt::TokenId, usize) {
281 let token_id = tt::TokenId(self.next_id);
283 let idx = self.map.insert_delim(
285 open_abs_range - self.global_offset,
286 open_abs_range - self.global_offset,
291 fn close_delim(&mut self, idx: usize, close_abs_range: Option<TextRange>) {
292 match close_abs_range {
294 self.map.remove_delim(idx);
297 self.map.update_close_delim(idx, close - self.global_offset);
303 /// A Raw Token (straightly from lexer) convertor
304 struct RawConvertor<'a> {
307 id_alloc: TokenIdAlloc,
308 inner: std::slice::Iter<'a, RawToken>,
311 trait SrcToken: std::fmt::Debug {
312 fn kind(&self) -> SyntaxKind;
314 fn to_char(&self) -> Option<char>;
316 fn to_text(&self) -> SmolStr;
319 trait TokenConvertor {
320 type Token: SrcToken;
322 fn go(&mut self) -> Option<tt::Subtree> {
323 let mut subtree = tt::Subtree::default();
324 subtree.delimiter = None;
325 while self.peek().is_some() {
326 self.collect_leaf(&mut subtree.token_trees);
328 if subtree.token_trees.is_empty() {
331 if subtree.token_trees.len() == 1 {
332 if let tt::TokenTree::Subtree(first) = &subtree.token_trees[0] {
333 return Some(first.clone());
339 fn collect_leaf(&mut self, result: &mut Vec<tt::TokenTree>) {
340 let (token, range) = match self.bump() {
345 let k: SyntaxKind = token.kind();
347 if let Some(tokens) = self.convert_doc_comment(&token) {
348 result.extend(tokens);
353 result.push(if k.is_punct() && k != UNDERSCORE {
354 assert_eq!(range.len(), TextSize::of('.'));
355 let delim = match k {
356 T!['('] => Some((tt::DelimiterKind::Parenthesis, T![')'])),
357 T!['{'] => Some((tt::DelimiterKind::Brace, T!['}'])),
358 T!['['] => Some((tt::DelimiterKind::Bracket, T![']'])),
362 if let Some((kind, closed)) = delim {
363 let mut subtree = tt::Subtree::default();
364 let (id, idx) = self.id_alloc().open_delim(range);
365 subtree.delimiter = Some(tt::Delimiter { kind, id });
367 while self.peek().map(|it| it.kind() != closed).unwrap_or(false) {
368 self.collect_leaf(&mut subtree.token_trees);
370 let last_range = match self.bump() {
372 // For error resilience, we insert an char punct for the opening delim here
373 self.id_alloc().close_delim(idx, None);
374 let leaf: tt::Leaf = tt::Punct {
375 id: self.id_alloc().alloc(range),
376 char: token.to_char().unwrap(),
377 spacing: tt::Spacing::Alone,
380 result.push(leaf.into());
381 result.extend(subtree.token_trees);
386 self.id_alloc().close_delim(idx, Some(last_range));
389 let spacing = match self.peek() {
391 if next.kind().is_trivia()
392 || next.kind() == T!['[']
393 || next.kind() == T!['{']
394 || next.kind() == T!['('] =>
398 Some(next) if next.kind().is_punct() && next.kind() != UNDERSCORE => {
401 _ => tt::Spacing::Alone,
403 let char = match token.to_char() {
406 panic!("Token from lexer must be single char: token = {:#?}", token);
409 tt::Leaf::from(tt::Punct { char, spacing, id: self.id_alloc().alloc(range) }).into()
412 macro_rules! make_leaf {
414 tt::$i { id: self.id_alloc().alloc(range), text: token.to_text() }.into()
417 let leaf: tt::Leaf = match k {
418 T![true] | T![false] => make_leaf!(Ident),
419 IDENT => make_leaf!(Ident),
420 UNDERSCORE => make_leaf!(Ident),
421 k if k.is_keyword() => make_leaf!(Ident),
422 k if k.is_literal() => make_leaf!(Literal),
424 let char_unit = TextSize::of('\'');
425 let r = TextRange::at(range.start(), char_unit);
426 let apostrophe = tt::Leaf::from(tt::Punct {
428 spacing: tt::Spacing::Joint,
429 id: self.id_alloc().alloc(r),
431 result.push(apostrophe.into());
433 let r = TextRange::at(range.start() + char_unit, range.len() - char_unit);
434 let ident = tt::Leaf::from(tt::Ident {
435 text: SmolStr::new(&token.to_text()[1..]),
436 id: self.id_alloc().alloc(r),
438 result.push(ident.into());
448 fn convert_doc_comment(&self, token: &Self::Token) -> Option<Vec<tt::TokenTree>>;
450 fn bump(&mut self) -> Option<(Self::Token, TextRange)>;
452 fn peek(&self) -> Option<Self::Token>;
454 fn id_alloc(&mut self) -> &mut TokenIdAlloc;
457 impl<'a> SrcToken for (&'a RawToken, &'a str) {
458 fn kind(&self) -> SyntaxKind {
462 fn to_char(&self) -> Option<char> {
463 self.1.chars().next()
466 fn to_text(&self) -> SmolStr {
471 impl RawConvertor<'_> {}
473 impl<'a> TokenConvertor for RawConvertor<'a> {
474 type Token = (&'a RawToken, &'a str);
476 fn convert_doc_comment(&self, token: &Self::Token) -> Option<Vec<tt::TokenTree>> {
477 convert_doc_comment(&doc_comment(token.1))
480 fn bump(&mut self) -> Option<(Self::Token, TextRange)> {
481 let token = self.inner.next()?;
482 let range = TextRange::at(self.offset, token.len);
483 self.offset += token.len;
485 Some(((token, &self.text[range]), range))
488 fn peek(&self) -> Option<Self::Token> {
489 let token = self.inner.as_slice().get(0);
492 let range = TextRange::at(self.offset, it.len);
493 (it, &self.text[range])
497 fn id_alloc(&mut self) -> &mut TokenIdAlloc {
503 id_alloc: TokenIdAlloc,
504 current: Option<SyntaxToken>,
506 punct_offset: Option<(SyntaxToken, TextSize)>,
510 fn new(node: &SyntaxNode, global_offset: TextSize) -> Convertor {
512 id_alloc: { TokenIdAlloc { map: TokenMap::default(), global_offset, next_id: 0 } },
513 current: node.first_token(),
514 range: node.text_range(),
522 Ordinary(SyntaxToken),
523 Punch(SyntaxToken, TextSize),
527 fn token(&self) -> &SyntaxToken {
529 SynToken::Ordinary(it) => it,
530 SynToken::Punch(it, _) => it,
535 impl SrcToken for SynToken {
536 fn kind(&self) -> SyntaxKind {
539 fn to_char(&self) -> Option<char> {
541 SynToken::Ordinary(_) => None,
542 SynToken::Punch(it, i) => it.text().chars().nth((*i).into()),
545 fn to_text(&self) -> SmolStr {
546 self.token().text().into()
550 impl TokenConvertor for Convertor {
551 type Token = SynToken;
552 fn convert_doc_comment(&self, token: &Self::Token) -> Option<Vec<tt::TokenTree>> {
553 convert_doc_comment(token.token())
556 fn bump(&mut self) -> Option<(Self::Token, TextRange)> {
557 if let Some((punct, offset)) = self.punct_offset.clone() {
558 if usize::from(offset) + 1 < punct.text().len() {
559 let offset = offset + TextSize::of('.');
560 let range = punct.text_range();
561 self.punct_offset = Some((punct.clone(), offset));
562 let range = TextRange::at(range.start() + offset, TextSize::of('.'));
563 return Some((SynToken::Punch(punct, offset), range));
567 let curr = self.current.clone()?;
568 if !&self.range.contains_range(curr.text_range()) {
571 self.current = curr.next_token();
573 let token = if curr.kind().is_punct() {
574 let range = curr.text_range();
575 let range = TextRange::at(range.start(), TextSize::of('.'));
576 self.punct_offset = Some((curr.clone(), 0.into()));
577 (SynToken::Punch(curr, 0.into()), range)
579 self.punct_offset = None;
580 let range = curr.text_range();
581 (SynToken::Ordinary(curr), range)
587 fn peek(&self) -> Option<Self::Token> {
588 if let Some((punct, mut offset)) = self.punct_offset.clone() {
589 offset = offset + TextSize::of('.');
590 if usize::from(offset) < punct.text().len() {
591 return Some(SynToken::Punch(punct, offset));
595 let curr = self.current.clone()?;
596 if !self.range.contains_range(curr.text_range()) {
600 let token = if curr.kind().is_punct() {
601 SynToken::Punch(curr, 0.into())
603 SynToken::Ordinary(curr)
608 fn id_alloc(&mut self) -> &mut TokenIdAlloc {
613 struct TtTreeSink<'a> {
616 open_delims: FxHashMap<tt::TokenId, TextSize>,
618 inner: SyntaxTreeBuilder,
622 // Use for detect ill-form tree which is not single root
623 roots: smallvec::SmallVec<[usize; 1]>,
626 impl<'a> TtTreeSink<'a> {
627 fn new(cursor: Cursor<'a>) -> Self {
631 open_delims: FxHashMap::default(),
633 inner: SyntaxTreeBuilder::default(),
634 roots: smallvec::SmallVec::new(),
635 token_map: TokenMap::default(),
639 fn finish(mut self) -> (Parse<SyntaxNode>, TokenMap) {
640 self.token_map.entries.shrink_to_fit();
641 (self.inner.finish(), self.token_map)
645 fn delim_to_str(d: Option<tt::DelimiterKind>, closing: bool) -> &'static str {
646 let texts = match d {
647 Some(tt::DelimiterKind::Parenthesis) => "()",
648 Some(tt::DelimiterKind::Brace) => "{}",
649 Some(tt::DelimiterKind::Bracket) => "[]",
653 let idx = closing as usize;
654 &texts[idx..texts.len() - (1 - idx)]
657 impl<'a> TreeSink for TtTreeSink<'a> {
658 fn token(&mut self, kind: SyntaxKind, mut n_tokens: u8) {
659 if kind == L_DOLLAR || kind == R_DOLLAR {
660 self.cursor = self.cursor.bump_subtree();
663 if kind == LIFETIME_IDENT {
667 let mut last = self.cursor;
668 for _ in 0..n_tokens {
669 let tmp_str: SmolStr;
670 if self.cursor.eof() {
674 let text: &str = match self.cursor.token_tree() {
675 Some(tt::buffer::TokenTreeRef::Leaf(leaf, _)) => {
676 // Mark the range if needed
677 let (text, id) = match leaf {
678 tt::Leaf::Ident(ident) => (&ident.text, ident.id),
679 tt::Leaf::Punct(punct) => {
680 assert!(punct.char.is_ascii());
681 let char = &(punct.char as u8);
682 tmp_str = SmolStr::new_inline(
683 std::str::from_utf8(std::slice::from_ref(char)).unwrap(),
687 tt::Leaf::Literal(lit) => (&lit.text, lit.id),
689 let range = TextRange::at(self.text_pos, TextSize::of(text.as_str()));
690 self.token_map.insert(id, range);
691 self.cursor = self.cursor.bump();
694 Some(tt::buffer::TokenTreeRef::Subtree(subtree, _)) => {
695 self.cursor = self.cursor.subtree().unwrap();
696 if let Some(id) = subtree.delimiter.map(|it| it.id) {
697 self.open_delims.insert(id, self.text_pos);
699 delim_to_str(subtree.delimiter_kind(), false)
702 if let Some(parent) = self.cursor.end() {
703 self.cursor = self.cursor.bump();
704 if let Some(id) = parent.delimiter.map(|it| it.id) {
705 if let Some(open_delim) = self.open_delims.get(&id) {
706 let open_range = TextRange::at(*open_delim, TextSize::of('('));
707 let close_range = TextRange::at(self.text_pos, TextSize::of('('));
708 self.token_map.insert_delim(id, open_range, close_range);
711 delim_to_str(parent.delimiter_kind(), true)
718 self.text_pos += TextSize::of(text);
721 self.inner.token(kind, self.buf.as_str());
723 // Add whitespace between adjoint puncts
724 let next = last.bump();
726 Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Punct(curr), _)),
727 Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Punct(_), _)),
728 ) = (last.token_tree(), next.token_tree())
730 // Note: We always assume the semi-colon would be the last token in
731 // other parts of RA such that we don't add whitespace here.
732 if curr.spacing == tt::Spacing::Alone && curr.char != ';' {
733 self.inner.token(WHITESPACE, " ");
734 self.text_pos += TextSize::of(' ');
739 fn start_node(&mut self, kind: SyntaxKind) {
740 self.inner.start_node(kind);
742 match self.roots.last_mut() {
743 None | Some(0) => self.roots.push(1),
744 Some(ref mut n) => **n += 1,
748 fn finish_node(&mut self) {
749 self.inner.finish_node();
750 *self.roots.last_mut().unwrap() -= 1;
753 fn error(&mut self, error: ParseError) {
754 self.inner.error(error, self.text_pos)
761 use crate::tests::parse_macro;
762 use parser::TokenSource;
764 algo::{insert_children, InsertPosition},
769 fn convert_tt_token_source() {
770 let expansion = parse_macro(
772 macro_rules! literals {
784 .expand_tt("literals!(foo);");
785 let tts = &[expansion.into()];
786 let buffer = tt::buffer::TokenBuffer::from_tokens(tts);
787 let mut tt_src = SubtreeTokenSource::new(&buffer);
788 let mut tokens = vec![];
789 while tt_src.current().kind != EOF {
790 tokens.push((tt_src.current().kind, tt_src.text()));
795 // [let] [a] [=] ['c'] [;]
796 assert_eq!(tokens[2 + 3].1, "'c'");
797 assert_eq!(tokens[2 + 3].0, CHAR);
798 // [let] [c] [=] [1000] [;]
799 assert_eq!(tokens[2 + 5 + 3].1, "1000");
800 assert_eq!(tokens[2 + 5 + 3].0, INT_NUMBER);
801 // [let] [f] [=] [12E+99_f64] [;]
802 assert_eq!(tokens[2 + 10 + 3].1, "12E+99_f64");
803 assert_eq!(tokens[2 + 10 + 3].0, FLOAT_NUMBER);
805 // [let] [s] [=] ["rust1"] [;]
806 assert_eq!(tokens[2 + 15 + 3].1, "\"rust1\"");
807 assert_eq!(tokens[2 + 15 + 3].0, STRING);
811 fn stmts_token_trees_to_expr_is_err() {
812 let expansion = parse_macro(
824 .expand_tt("stmts!();");
825 assert!(token_tree_to_syntax_node(&expansion, FragmentKind::Expr).is_err());
829 fn test_token_tree_last_child_is_white_space() {
830 let source_file = ast::SourceFile::parse("f!({} );").ok().unwrap();
831 let macro_call = source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
832 let token_tree = macro_call.token_tree().unwrap();
834 // Token Tree now is :
844 token_tree.syntax().descendants_with_tokens().find(|it| it.kind() == T!['}']).unwrap();
845 let space = token_tree
847 .descendants_with_tokens()
848 .find(|it| it.kind() == SyntaxKind::WHITESPACE)
851 // reorder th white space, such that the white is inside the inner token-tree.
852 let token_tree = insert_children(
853 &rbrace.parent().unwrap(),
854 InsertPosition::Last,
855 std::iter::once(space),
858 // Token Tree now is :
863 let token_tree = ast::TokenTree::cast(token_tree).unwrap();
864 let tt = ast_to_token_tree(&token_tree).unwrap().0;
866 assert_eq!(tt.delimiter_kind(), Some(tt::DelimiterKind::Brace));
870 fn test_token_tree_multi_char_punct() {
871 let source_file = ast::SourceFile::parse("struct Foo { a: x::Y }").ok().unwrap();
872 let struct_def = source_file.syntax().descendants().find_map(ast::Struct::cast).unwrap();
873 let tt = ast_to_token_tree(&struct_def).unwrap().0;
874 token_tree_to_syntax_node(&tt, FragmentKind::Item).unwrap();