1 //! Conversions between [`SyntaxNode`] and [`tt::TokenTree`].
3 use parser::{ParseError, TreeSink};
4 use rustc_hash::{FxHashMap, FxHashSet};
6 ast::{self, make::tokens::doc_comment},
7 tokenize, AstToken, Parse, PreorderWithTokens, SmolStr, SyntaxElement, SyntaxKind,
9 SyntaxNode, SyntaxToken, SyntaxTreeBuilder, TextRange, TextSize, Token as RawToken, WalkEvent,
12 use tt::buffer::{Cursor, TokenBuffer};
15 subtree_source::SubtreeTokenSource, tt_iter::TtIter, ExpandError, ParserEntryPoint, TokenMap,
18 /// Convert the syntax node to a `TokenTree` (what macro
20 pub fn syntax_node_to_token_tree(node: &SyntaxNode) -> (tt::Subtree, TokenMap) {
21 syntax_node_to_token_tree_censored(node, &Default::default())
24 /// Convert the syntax node to a `TokenTree` (what macro will consume)
25 /// with the censored range excluded.
26 pub fn syntax_node_to_token_tree_censored(
28 censor: &FxHashSet<SyntaxNode>,
29 ) -> (tt::Subtree, TokenMap) {
30 let global_offset = node.text_range().start();
31 let mut c = Convertor::new(node, global_offset, censor);
32 let subtree = convert_tokens(&mut c);
33 c.id_alloc.map.shrink_to_fit();
34 (subtree, c.id_alloc.map)
37 // The following items are what `rustc` macro can be parsed into :
38 // link: https://github.com/rust-lang/rust/blob/9ebf47851a357faa4cd97f4b1dc7835f6376e639/src/libsyntax/ext/expand.rs#L141
39 // * Expr(P<ast::Expr>) -> token_tree_to_expr
40 // * Pat(P<ast::Pat>) -> token_tree_to_pat
41 // * Ty(P<ast::Ty>) -> token_tree_to_ty
42 // * Stmts(SmallVec<[ast::Stmt; 1]>) -> token_tree_to_stmts
43 // * Items(SmallVec<[P<ast::Item>; 1]>) -> token_tree_to_items
45 // * TraitItems(SmallVec<[ast::TraitItem; 1]>)
46 // * AssocItems(SmallVec<[ast::AssocItem; 1]>)
47 // * ForeignItems(SmallVec<[ast::ForeignItem; 1]>
49 pub fn token_tree_to_syntax_node(
51 entry_point: ParserEntryPoint,
52 ) -> Result<(Parse<SyntaxNode>, TokenMap), ExpandError> {
53 let buffer = match tt {
54 tt::Subtree { delimiter: None, token_trees } => {
55 TokenBuffer::from_tokens(token_trees.as_slice())
57 _ => TokenBuffer::from_subtree(tt),
59 let mut token_source = SubtreeTokenSource::new(&buffer);
60 let mut tree_sink = TtTreeSink::new(buffer.begin());
61 parser::parse(&mut token_source, &mut tree_sink, entry_point);
62 if tree_sink.roots.len() != 1 {
63 return Err(ExpandError::ConversionError);
65 //FIXME: would be cool to report errors
66 let (parse, range_map) = tree_sink.finish();
67 Ok((parse, range_map))
70 /// Convert a string to a `TokenTree`
71 pub fn parse_to_token_tree(text: &str) -> Option<(tt::Subtree, TokenMap)> {
72 let (tokens, errors) = tokenize(text);
73 if !errors.is_empty() {
77 let mut conv = RawConvertor {
79 offset: TextSize::default(),
81 id_alloc: TokenIdAlloc {
82 map: Default::default(),
83 global_offset: TextSize::default(),
88 let subtree = convert_tokens(&mut conv);
89 Some((subtree, conv.id_alloc.map))
92 /// Split token tree with separate expr: $($e:expr)SEP*
93 pub fn parse_exprs_with_sep(tt: &tt::Subtree, sep: char) -> Vec<tt::Subtree> {
94 if tt.token_trees.is_empty() {
98 let mut iter = TtIter::new(tt);
99 let mut res = Vec::new();
101 while iter.peek_n(0).is_some() {
102 let expanded = iter.expect_fragment(ParserEntryPoint::Expr);
104 res.push(match expanded.value {
106 Some(tt @ tt::TokenTree::Leaf(_)) => {
107 tt::Subtree { delimiter: None, token_trees: vec![tt] }
109 Some(tt::TokenTree::Subtree(tt)) => tt,
112 let mut fork = iter.clone();
113 if fork.expect_char(sep).is_err() {
119 if iter.peek_n(0).is_some() {
120 res.push(tt::Subtree { delimiter: None, token_trees: iter.into_iter().cloned().collect() });
126 fn convert_tokens<C: TokenConvertor>(conv: &mut C) -> tt::Subtree {
128 subtree: tt::Subtree,
130 open_range: TextRange,
133 let entry = StackEntry {
134 subtree: tt::Subtree { delimiter: None, ..Default::default() },
135 // never used (delimiter is `None`)
137 open_range: TextRange::empty(TextSize::of('.')),
139 let mut stack = vec![entry];
142 let entry = stack.last_mut().unwrap();
143 let result = &mut entry.subtree.token_trees;
144 let (token, range) = match conv.bump() {
149 let k: SyntaxKind = token.kind();
151 if let Some(tokens) = conv.convert_doc_comment(&token) {
152 result.extend(tokens);
157 result.push(if k.is_punct() && k != UNDERSCORE {
158 assert_eq!(range.len(), TextSize::of('.'));
160 if let Some(delim) = entry.subtree.delimiter {
161 let expected = match delim.kind {
162 tt::DelimiterKind::Parenthesis => T![')'],
163 tt::DelimiterKind::Brace => T!['}'],
164 tt::DelimiterKind::Bracket => T![']'],
168 let entry = stack.pop().unwrap();
169 conv.id_alloc().close_delim(entry.idx, Some(range));
170 stack.last_mut().unwrap().subtree.token_trees.push(entry.subtree.into());
175 let delim = match k {
176 T!['('] => Some(tt::DelimiterKind::Parenthesis),
177 T!['{'] => Some(tt::DelimiterKind::Brace),
178 T!['['] => Some(tt::DelimiterKind::Bracket),
182 if let Some(kind) = delim {
183 let mut subtree = tt::Subtree::default();
184 let (id, idx) = conv.id_alloc().open_delim(range);
185 subtree.delimiter = Some(tt::Delimiter { id, kind });
186 stack.push(StackEntry { subtree, idx, open_range: range });
189 let spacing = match conv.peek() {
191 if next.kind().is_trivia()
192 || next.kind() == T!['[']
193 || next.kind() == T!['{']
194 || next.kind() == T!['('] =>
198 Some(next) if next.kind().is_punct() && next.kind() != UNDERSCORE => {
201 _ => tt::Spacing::Alone,
203 let char = match token.to_char() {
206 panic!("Token from lexer must be single char: token = {:#?}", token);
209 tt::Leaf::from(tt::Punct { char, spacing, id: conv.id_alloc().alloc(range) }).into()
212 macro_rules! make_leaf {
214 tt::$i { id: conv.id_alloc().alloc(range), text: token.to_text() }.into()
217 let leaf: tt::Leaf = match k {
218 T![true] | T![false] => make_leaf!(Ident),
219 IDENT => make_leaf!(Ident),
220 UNDERSCORE => make_leaf!(Ident),
221 k if k.is_keyword() => make_leaf!(Ident),
222 k if k.is_literal() => make_leaf!(Literal),
224 let char_unit = TextSize::of('\'');
225 let r = TextRange::at(range.start(), char_unit);
226 let apostrophe = tt::Leaf::from(tt::Punct {
228 spacing: tt::Spacing::Joint,
229 id: conv.id_alloc().alloc(r),
231 result.push(apostrophe.into());
233 let r = TextRange::at(range.start() + char_unit, range.len() - char_unit);
234 let ident = tt::Leaf::from(tt::Ident {
235 text: SmolStr::new(&token.to_text()[1..]),
236 id: conv.id_alloc().alloc(r),
238 result.push(ident.into());
248 // If we get here, we've consumed all input tokens.
249 // We might have more than one subtree in the stack, if the delimiters are improperly balanced.
250 // Merge them so we're left with one.
251 while stack.len() > 1 {
252 let entry = stack.pop().unwrap();
253 let parent = stack.last_mut().unwrap();
255 conv.id_alloc().close_delim(entry.idx, None);
256 let leaf: tt::Leaf = tt::Punct {
257 id: conv.id_alloc().alloc(entry.open_range),
258 char: match entry.subtree.delimiter.unwrap().kind {
259 tt::DelimiterKind::Parenthesis => '(',
260 tt::DelimiterKind::Brace => '{',
261 tt::DelimiterKind::Bracket => '[',
263 spacing: tt::Spacing::Alone,
266 parent.subtree.token_trees.push(leaf.into());
267 parent.subtree.token_trees.extend(entry.subtree.token_trees);
270 let subtree = stack.pop().unwrap().subtree;
271 if subtree.token_trees.len() == 1 {
272 if let tt::TokenTree::Subtree(first) = &subtree.token_trees[0] {
273 return first.clone();
279 /// Returns the textual content of a doc comment block as a quoted string
280 /// That is, strips leading `///` (or `/**`, etc)
281 /// and strips the ending `*/`
282 /// And then quote the string, which is needed to convert to `tt::Literal`
283 fn doc_comment_text(comment: &ast::Comment) -> SmolStr {
284 let prefix_len = comment.prefix().len();
285 let mut text = &comment.text()[prefix_len..];
287 // Remove ending "*/"
288 if comment.kind().shape == ast::CommentShape::Block {
289 text = &text[0..text.len() - 2];
293 // Note that `tt::Literal` expect an escaped string
294 let text = format!("\"{}\"", text.escape_debug());
298 fn convert_doc_comment(token: &syntax::SyntaxToken) -> Option<Vec<tt::TokenTree>> {
299 let comment = ast::Comment::cast(token.clone())?;
300 let doc = comment.kind().doc?;
302 // Make `doc="\" Comments\""
303 let meta_tkns = vec![mk_ident("doc"), mk_punct('='), mk_doc_literal(&comment)];
306 let mut token_trees = vec![mk_punct('#')];
307 if let ast::CommentPlacement::Inner = doc {
308 token_trees.push(mk_punct('!'));
310 token_trees.push(tt::TokenTree::from(tt::Subtree {
311 delimiter: Some(tt::Delimiter {
312 kind: tt::DelimiterKind::Bracket,
313 id: tt::TokenId::unspecified(),
315 token_trees: meta_tkns,
318 return Some(token_trees);
321 fn mk_ident(s: &str) -> tt::TokenTree {
322 tt::TokenTree::from(tt::Leaf::from(tt::Ident {
324 id: tt::TokenId::unspecified(),
328 fn mk_punct(c: char) -> tt::TokenTree {
329 tt::TokenTree::from(tt::Leaf::from(tt::Punct {
331 spacing: tt::Spacing::Alone,
332 id: tt::TokenId::unspecified(),
336 fn mk_doc_literal(comment: &ast::Comment) -> tt::TokenTree {
337 let lit = tt::Literal { text: doc_comment_text(comment), id: tt::TokenId::unspecified() };
339 tt::TokenTree::from(tt::Leaf::from(lit))
343 struct TokenIdAlloc {
345 global_offset: TextSize,
350 fn alloc(&mut self, absolute_range: TextRange) -> tt::TokenId {
351 let relative_range = absolute_range - self.global_offset;
352 let token_id = tt::TokenId(self.next_id);
354 self.map.insert(token_id, relative_range);
358 fn open_delim(&mut self, open_abs_range: TextRange) -> (tt::TokenId, usize) {
359 let token_id = tt::TokenId(self.next_id);
361 let idx = self.map.insert_delim(
363 open_abs_range - self.global_offset,
364 open_abs_range - self.global_offset,
369 fn close_delim(&mut self, idx: usize, close_abs_range: Option<TextRange>) {
370 match close_abs_range {
372 self.map.remove_delim(idx);
375 self.map.update_close_delim(idx, close - self.global_offset);
381 /// A Raw Token (straightly from lexer) convertor
382 struct RawConvertor<'a> {
385 id_alloc: TokenIdAlloc,
386 inner: std::slice::Iter<'a, RawToken>,
389 trait SrcToken: std::fmt::Debug {
390 fn kind(&self) -> SyntaxKind;
392 fn to_char(&self) -> Option<char>;
394 fn to_text(&self) -> SmolStr;
397 trait TokenConvertor {
398 type Token: SrcToken;
400 fn convert_doc_comment(&self, token: &Self::Token) -> Option<Vec<tt::TokenTree>>;
402 fn bump(&mut self) -> Option<(Self::Token, TextRange)>;
404 fn peek(&self) -> Option<Self::Token>;
406 fn id_alloc(&mut self) -> &mut TokenIdAlloc;
409 impl<'a> SrcToken for (&'a RawToken, &'a str) {
410 fn kind(&self) -> SyntaxKind {
414 fn to_char(&self) -> Option<char> {
415 self.1.chars().next()
418 fn to_text(&self) -> SmolStr {
423 impl<'a> TokenConvertor for RawConvertor<'a> {
424 type Token = (&'a RawToken, &'a str);
426 fn convert_doc_comment(&self, token: &Self::Token) -> Option<Vec<tt::TokenTree>> {
427 convert_doc_comment(&doc_comment(token.1))
430 fn bump(&mut self) -> Option<(Self::Token, TextRange)> {
431 let token = self.inner.next()?;
432 let range = TextRange::at(self.offset, token.len);
433 self.offset += token.len;
435 Some(((token, &self.text[range]), range))
438 fn peek(&self) -> Option<Self::Token> {
439 let token = self.inner.as_slice().get(0);
442 let range = TextRange::at(self.offset, it.len);
443 (it, &self.text[range])
447 fn id_alloc(&mut self) -> &mut TokenIdAlloc {
452 struct Convertor<'c> {
453 id_alloc: TokenIdAlloc,
454 current: Option<SyntaxToken>,
455 preorder: PreorderWithTokens,
456 censor: &'c FxHashSet<SyntaxNode>,
458 punct_offset: Option<(SyntaxToken, TextSize)>,
461 impl<'c> Convertor<'c> {
464 global_offset: TextSize,
465 censor: &'c FxHashSet<SyntaxNode>,
467 let range = node.text_range();
468 let mut preorder = node.preorder_with_tokens();
469 let first = Self::next_token(&mut preorder, censor);
471 id_alloc: { TokenIdAlloc { map: TokenMap::default(), global_offset, next_id: 0 } },
481 preorder: &mut PreorderWithTokens,
482 censor: &FxHashSet<SyntaxNode>,
483 ) -> Option<SyntaxToken> {
484 while let Some(ev) = preorder.next() {
486 WalkEvent::Enter(ele) => ele,
490 SyntaxElement::Token(t) => return Some(t),
491 SyntaxElement::Node(node) if censor.contains(&node) => preorder.skip_subtree(),
492 SyntaxElement::Node(_) => (),
501 Ordinary(SyntaxToken),
502 Punch(SyntaxToken, TextSize),
506 fn token(&self) -> &SyntaxToken {
508 SynToken::Ordinary(it) => it,
509 SynToken::Punch(it, _) => it,
514 impl SrcToken for SynToken {
515 fn kind(&self) -> SyntaxKind {
518 fn to_char(&self) -> Option<char> {
520 SynToken::Ordinary(_) => None,
521 SynToken::Punch(it, i) => it.text().chars().nth((*i).into()),
524 fn to_text(&self) -> SmolStr {
525 self.token().text().into()
529 impl TokenConvertor for Convertor<'_> {
530 type Token = SynToken;
531 fn convert_doc_comment(&self, token: &Self::Token) -> Option<Vec<tt::TokenTree>> {
532 convert_doc_comment(token.token())
535 fn bump(&mut self) -> Option<(Self::Token, TextRange)> {
536 if let Some((punct, offset)) = self.punct_offset.clone() {
537 if usize::from(offset) + 1 < punct.text().len() {
538 let offset = offset + TextSize::of('.');
539 let range = punct.text_range();
540 self.punct_offset = Some((punct.clone(), offset));
541 let range = TextRange::at(range.start() + offset, TextSize::of('.'));
542 return Some((SynToken::Punch(punct, offset), range));
546 let curr = self.current.clone()?;
547 if !&self.range.contains_range(curr.text_range()) {
550 self.current = Self::next_token(&mut self.preorder, self.censor);
551 let token = if curr.kind().is_punct() {
552 let range = curr.text_range();
553 let range = TextRange::at(range.start(), TextSize::of('.'));
554 self.punct_offset = Some((curr.clone(), 0.into()));
555 (SynToken::Punch(curr, 0.into()), range)
557 self.punct_offset = None;
558 let range = curr.text_range();
559 (SynToken::Ordinary(curr), range)
565 fn peek(&self) -> Option<Self::Token> {
566 if let Some((punct, mut offset)) = self.punct_offset.clone() {
567 offset += TextSize::of('.');
568 if usize::from(offset) < punct.text().len() {
569 return Some(SynToken::Punch(punct, offset));
573 let curr = self.current.clone()?;
574 if !self.range.contains_range(curr.text_range()) {
578 let token = if curr.kind().is_punct() {
579 SynToken::Punch(curr, 0.into())
581 SynToken::Ordinary(curr)
586 fn id_alloc(&mut self) -> &mut TokenIdAlloc {
591 struct TtTreeSink<'a> {
594 open_delims: FxHashMap<tt::TokenId, TextSize>,
596 inner: SyntaxTreeBuilder,
600 // Use for detect ill-form tree which is not single root
601 roots: smallvec::SmallVec<[usize; 1]>,
604 impl<'a> TtTreeSink<'a> {
605 fn new(cursor: Cursor<'a>) -> Self {
609 open_delims: FxHashMap::default(),
611 inner: SyntaxTreeBuilder::default(),
612 roots: smallvec::SmallVec::new(),
613 token_map: TokenMap::default(),
617 fn finish(mut self) -> (Parse<SyntaxNode>, TokenMap) {
618 self.token_map.shrink_to_fit();
619 (self.inner.finish(), self.token_map)
623 fn delim_to_str(d: Option<tt::DelimiterKind>, closing: bool) -> &'static str {
624 let texts = match d {
625 Some(tt::DelimiterKind::Parenthesis) => "()",
626 Some(tt::DelimiterKind::Brace) => "{}",
627 Some(tt::DelimiterKind::Bracket) => "[]",
631 let idx = closing as usize;
632 &texts[idx..texts.len() - (1 - idx)]
635 impl<'a> TreeSink for TtTreeSink<'a> {
636 fn token(&mut self, kind: SyntaxKind, mut n_tokens: u8) {
637 if kind == L_DOLLAR || kind == R_DOLLAR {
638 self.cursor = self.cursor.bump_subtree();
641 if kind == LIFETIME_IDENT {
645 let mut last = self.cursor;
646 for _ in 0..n_tokens {
647 let tmp_str: SmolStr;
648 if self.cursor.eof() {
652 let text: &str = match self.cursor.token_tree() {
653 Some(tt::buffer::TokenTreeRef::Leaf(leaf, _)) => {
654 // Mark the range if needed
655 let (text, id) = match leaf {
656 tt::Leaf::Ident(ident) => (&ident.text, ident.id),
657 tt::Leaf::Punct(punct) => {
658 assert!(punct.char.is_ascii());
659 let char = &(punct.char as u8);
660 tmp_str = SmolStr::new_inline(
661 std::str::from_utf8(std::slice::from_ref(char)).unwrap(),
665 tt::Leaf::Literal(lit) => (&lit.text, lit.id),
667 let range = TextRange::at(self.text_pos, TextSize::of(text.as_str()));
668 self.token_map.insert(id, range);
669 self.cursor = self.cursor.bump();
672 Some(tt::buffer::TokenTreeRef::Subtree(subtree, _)) => {
673 self.cursor = self.cursor.subtree().unwrap();
674 if let Some(id) = subtree.delimiter.map(|it| it.id) {
675 self.open_delims.insert(id, self.text_pos);
677 delim_to_str(subtree.delimiter_kind(), false)
680 if let Some(parent) = self.cursor.end() {
681 self.cursor = self.cursor.bump();
682 if let Some(id) = parent.delimiter.map(|it| it.id) {
683 if let Some(open_delim) = self.open_delims.get(&id) {
684 let open_range = TextRange::at(*open_delim, TextSize::of('('));
685 let close_range = TextRange::at(self.text_pos, TextSize::of('('));
686 self.token_map.insert_delim(id, open_range, close_range);
689 delim_to_str(parent.delimiter_kind(), true)
696 self.text_pos += TextSize::of(text);
699 self.inner.token(kind, self.buf.as_str());
701 // Add whitespace between adjoint puncts
702 let next = last.bump();
704 Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Punct(curr), _)),
705 Some(tt::buffer::TokenTreeRef::Leaf(tt::Leaf::Punct(_), _)),
706 ) = (last.token_tree(), next.token_tree())
708 // Note: We always assume the semi-colon would be the last token in
709 // other parts of RA such that we don't add whitespace here.
710 if curr.spacing == tt::Spacing::Alone && curr.char != ';' {
711 self.inner.token(WHITESPACE, " ");
712 self.text_pos += TextSize::of(' ');
717 fn start_node(&mut self, kind: SyntaxKind) {
718 self.inner.start_node(kind);
720 match self.roots.last_mut() {
721 None | Some(0) => self.roots.push(1),
722 Some(ref mut n) => **n += 1,
726 fn finish_node(&mut self) {
727 self.inner.finish_node();
728 *self.roots.last_mut().unwrap() -= 1;
731 fn error(&mut self, error: ParseError) {
732 self.inner.error(error, self.text_pos)
739 use crate::tests::parse_macro;
740 use parser::TokenSource;
742 ast::{make, AstNode},
745 use test_utils::assert_eq_text;
748 fn convert_tt_token_source() {
749 let expansion = parse_macro(
751 macro_rules! literals {
763 .expand_tt("literals!(foo);");
764 let tts = &[expansion.into()];
765 let buffer = tt::buffer::TokenBuffer::from_tokens(tts);
766 let mut tt_src = SubtreeTokenSource::new(&buffer);
767 let mut tokens = vec![];
768 while tt_src.current().kind != EOF {
769 tokens.push((tt_src.current().kind, tt_src.text()));
774 // [let] [a] [=] ['c'] [;]
775 assert_eq!(tokens[2 + 3].1, "'c'");
776 assert_eq!(tokens[2 + 3].0, CHAR);
777 // [let] [c] [=] [1000] [;]
778 assert_eq!(tokens[2 + 5 + 3].1, "1000");
779 assert_eq!(tokens[2 + 5 + 3].0, INT_NUMBER);
780 // [let] [f] [=] [12E+99_f64] [;]
781 assert_eq!(tokens[2 + 10 + 3].1, "12E+99_f64");
782 assert_eq!(tokens[2 + 10 + 3].0, FLOAT_NUMBER);
784 // [let] [s] [=] ["rust1"] [;]
785 assert_eq!(tokens[2 + 15 + 3].1, "\"rust1\"");
786 assert_eq!(tokens[2 + 15 + 3].0, STRING);
790 fn stmts_token_trees_to_expr_is_err() {
791 let expansion = parse_macro(
803 .expand_tt("stmts!();");
804 assert!(token_tree_to_syntax_node(&expansion, ParserEntryPoint::Expr).is_err());
808 fn test_token_tree_last_child_is_white_space() {
809 let source_file = ast::SourceFile::parse("f!{}").ok().unwrap();
810 let macro_call = source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
811 let token_tree = macro_call.token_tree().unwrap();
813 // Token Tree now is :
819 let token_tree = token_tree.clone_for_update();
820 ted::append_child(token_tree.syntax(), make::tokens::single_space());
821 let token_tree = token_tree.clone_subtree();
822 // Token Tree now is :
828 let tt = syntax_node_to_token_tree(token_tree.syntax()).0;
829 assert_eq!(tt.delimiter_kind(), Some(tt::DelimiterKind::Brace));
833 fn test_token_tree_multi_char_punct() {
834 let source_file = ast::SourceFile::parse("struct Foo { a: x::Y }").ok().unwrap();
835 let struct_def = source_file.syntax().descendants().find_map(ast::Struct::cast).unwrap();
836 let tt = syntax_node_to_token_tree(struct_def.syntax()).0;
837 token_tree_to_syntax_node(&tt, ParserEntryPoint::Item).unwrap();
841 fn test_missing_closing_delim() {
842 let source_file = ast::SourceFile::parse("m!(x").tree();
843 let node = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
844 let tt = syntax_node_to_token_tree(node.syntax()).0.to_string();
845 assert_eq_text!(&*tt, "( x");