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-rw-r--r--crates/ra_syntax/src/parsing/text_token_source.rs89
1 files changed, 43 insertions, 46 deletions
diff --git a/crates/ra_syntax/src/parsing/text_token_source.rs b/crates/ra_syntax/src/parsing/text_token_source.rs
index 7ddc2c2c3..97aa3e795 100644
--- a/crates/ra_syntax/src/parsing/text_token_source.rs
+++ b/crates/ra_syntax/src/parsing/text_token_source.rs
@@ -1,40 +1,35 @@
1//! FIXME: write short doc here 1//! See `TextTokenSource` docs.
2 2
3use ra_parser::Token as PToken;
4use ra_parser::TokenSource; 3use ra_parser::TokenSource;
5 4
6use crate::{parsing::lexer::Token, SyntaxKind::EOF, TextRange, TextSize}; 5use crate::{parsing::lexer::Token, SyntaxKind::EOF, TextRange, TextSize};
7 6
7/// Implementation of `ra_parser::TokenSource` that takes tokens from source code text.
8pub(crate) struct TextTokenSource<'t> { 8pub(crate) struct TextTokenSource<'t> {
9 text: &'t str, 9 text: &'t str,
10 /// start position of each token(expect whitespace and comment) 10 /// token and its start position (non-whitespace/comment tokens)
11 /// ```non-rust 11 /// ```non-rust
12 /// struct Foo; 12 /// struct Foo;
13 /// ^------^--- 13 /// ^------^--^-
14 /// | | ^- 14 /// | | \________
15 /// 0 7 10 15 /// | \____ \
16 /// | \ |
17 /// (struct, 0) (Foo, 7) (;, 10)
16 /// ``` 18 /// ```
17 /// (token, start_offset): `[(struct, 0), (Foo, 7), (;, 10)]` 19 /// `[(struct, 0), (Foo, 7), (;, 10)]`
18 start_offsets: Vec<TextSize>, 20 token_offset_pairs: Vec<(Token, TextSize)>,
19 /// non-whitespace/comment tokens
20 /// ```non-rust
21 /// struct Foo {}
22 /// ^^^^^^ ^^^ ^^
23 /// ```
24 /// tokens: `[struct, Foo, {, }]`
25 tokens: Vec<Token>,
26 21
27 /// Current token and position 22 /// Current token and position
28 curr: (PToken, usize), 23 curr: (ra_parser::Token, usize),
29} 24}
30 25
31impl<'t> TokenSource for TextTokenSource<'t> { 26impl<'t> TokenSource for TextTokenSource<'t> {
32 fn current(&self) -> PToken { 27 fn current(&self) -> ra_parser::Token {
33 self.curr.0 28 self.curr.0
34 } 29 }
35 30
36 fn lookahead_nth(&self, n: usize) -> PToken { 31 fn lookahead_nth(&self, n: usize) -> ra_parser::Token {
37 mk_token(self.curr.1 + n, &self.start_offsets, &self.tokens) 32 mk_token(self.curr.1 + n, &self.token_offset_pairs)
38 } 33 }
39 34
40 fn bump(&mut self) { 35 fn bump(&mut self) {
@@ -43,45 +38,47 @@ impl<'t> TokenSource for TextTokenSource<'t> {
43 } 38 }
44 39
45 let pos = self.curr.1 + 1; 40 let pos = self.curr.1 + 1;
46 self.curr = (mk_token(pos, &self.start_offsets, &self.tokens), pos); 41 self.curr = (mk_token(pos, &self.token_offset_pairs), pos);
47 } 42 }
48 43
49 fn is_keyword(&self, kw: &str) -> bool { 44 fn is_keyword(&self, kw: &str) -> bool {
50 let pos = self.curr.1; 45 self.token_offset_pairs
51 if pos >= self.tokens.len() { 46 .get(self.curr.1)
52 return false; 47 .map(|(token, offset)| &self.text[TextRange::at(*offset, token.len)] == kw)
53 } 48 .unwrap_or(false)
54 let range = TextRange::at(self.start_offsets[pos], self.tokens[pos].len);
55 self.text[range] == *kw
56 } 49 }
57} 50}
58 51
59fn mk_token(pos: usize, start_offsets: &[TextSize], tokens: &[Token]) -> PToken { 52fn mk_token(pos: usize, token_offset_pairs: &[(Token, TextSize)]) -> ra_parser::Token {
60 let kind = tokens.get(pos).map(|t| t.kind).unwrap_or(EOF); 53 let (kind, is_jointed_to_next) = match token_offset_pairs.get(pos) {
61 let is_jointed_to_next = if pos + 1 < start_offsets.len() { 54 Some((token, offset)) => (
62 start_offsets[pos] + tokens[pos].len == start_offsets[pos + 1] 55 token.kind,
63 } else { 56 token_offset_pairs
64 false 57 .get(pos + 1)
58 .map(|(_, next_offset)| offset + token.len == *next_offset)
59 .unwrap_or(false),
60 ),
61 None => (EOF, false),
65 }; 62 };
66 63 ra_parser::Token { kind, is_jointed_to_next }
67 PToken { kind, is_jointed_to_next }
68} 64}
69 65
70impl<'t> TextTokenSource<'t> { 66impl<'t> TextTokenSource<'t> {
71 /// Generate input from tokens(expect comment and whitespace). 67 /// Generate input from tokens(expect comment and whitespace).
72 pub fn new(text: &'t str, raw_tokens: &'t [Token]) -> TextTokenSource<'t> { 68 pub fn new(text: &'t str, raw_tokens: &'t [Token]) -> TextTokenSource<'t> {
73 let mut tokens = Vec::new(); 69 let token_offset_pairs: Vec<_> = raw_tokens
74 let mut start_offsets = Vec::new(); 70 .iter()
75 let mut len = 0.into(); 71 .filter_map({
76 for &token in raw_tokens.iter() { 72 let mut len = 0.into();
77 if !token.kind.is_trivia() { 73 move |token| {
78 tokens.push(token); 74 let pair = if token.kind.is_trivia() { None } else { Some((*token, len)) };
79 start_offsets.push(len); 75 len += token.len;
80 } 76 pair
81 len += token.len; 77 }
82 } 78 })
79 .collect();
83 80
84 let first = mk_token(0, &start_offsets, &tokens); 81 let first = mk_token(0, &token_offset_pairs);
85 TextTokenSource { text, start_offsets, tokens, curr: (first, 0) } 82 TextTokenSource { text, token_offset_pairs, curr: (first, 0) }
86 } 83 }
87} 84}