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authorAleksey Kladov <[email protected]>2020-08-12 17:26:51 +0100
committerAleksey Kladov <[email protected]>2020-08-12 17:30:53 +0100
commita1c187eef3ba08076aedb5154929f7eda8d1b424 (patch)
tree9d898eb9600b0c36a74e4f95238f679c683fa566 /crates/ra_syntax/src/parsing/reparsing.rs
parent3d6889cba72a9d02199f7adaa2ecc69bc30af834 (diff)
Rename ra_syntax -> syntax
Diffstat (limited to 'crates/ra_syntax/src/parsing/reparsing.rs')
-rw-r--r--crates/ra_syntax/src/parsing/reparsing.rs455
1 files changed, 0 insertions, 455 deletions
diff --git a/crates/ra_syntax/src/parsing/reparsing.rs b/crates/ra_syntax/src/parsing/reparsing.rs
deleted file mode 100644
index 4149f856a..000000000
--- a/crates/ra_syntax/src/parsing/reparsing.rs
+++ /dev/null
@@ -1,455 +0,0 @@
1//! Implementation of incremental re-parsing.
2//!
3//! We use two simple strategies for this:
4//! - if the edit modifies only a single token (like changing an identifier's
5//! letter), we replace only this token.
6//! - otherwise, we search for the nearest `{}` block which contains the edit
7//! and try to parse only this block.
8
9use parser::Reparser;
10use text_edit::Indel;
11
12use crate::{
13 algo,
14 parsing::{
15 lexer::{lex_single_syntax_kind, tokenize, Token},
16 text_token_source::TextTokenSource,
17 text_tree_sink::TextTreeSink,
18 },
19 syntax_node::{GreenNode, GreenToken, NodeOrToken, SyntaxElement, SyntaxNode},
20 SyntaxError,
21 SyntaxKind::*,
22 TextRange, TextSize, T,
23};
24
25pub(crate) fn incremental_reparse(
26 node: &SyntaxNode,
27 edit: &Indel,
28 errors: Vec<SyntaxError>,
29) -> Option<(GreenNode, Vec<SyntaxError>, TextRange)> {
30 if let Some((green, new_errors, old_range)) = reparse_token(node, &edit) {
31 return Some((green, merge_errors(errors, new_errors, old_range, edit), old_range));
32 }
33
34 if let Some((green, new_errors, old_range)) = reparse_block(node, &edit) {
35 return Some((green, merge_errors(errors, new_errors, old_range, edit), old_range));
36 }
37 None
38}
39
40fn reparse_token<'node>(
41 root: &'node SyntaxNode,
42 edit: &Indel,
43) -> Option<(GreenNode, Vec<SyntaxError>, TextRange)> {
44 let prev_token = algo::find_covering_element(root, edit.delete).as_token()?.clone();
45 let prev_token_kind = prev_token.kind();
46 match prev_token_kind {
47 WHITESPACE | COMMENT | IDENT | STRING | RAW_STRING => {
48 if prev_token_kind == WHITESPACE || prev_token_kind == COMMENT {
49 // removing a new line may extends previous token
50 let deleted_range = edit.delete - prev_token.text_range().start();
51 if prev_token.text()[deleted_range].contains('\n') {
52 return None;
53 }
54 }
55
56 let mut new_text = get_text_after_edit(prev_token.clone().into(), &edit);
57 let (new_token_kind, new_err) = lex_single_syntax_kind(&new_text)?;
58
59 if new_token_kind != prev_token_kind
60 || (new_token_kind == IDENT && is_contextual_kw(&new_text))
61 {
62 return None;
63 }
64
65 // Check that edited token is not a part of the bigger token.
66 // E.g. if for source code `bruh"str"` the user removed `ruh`, then
67 // `b` no longer remains an identifier, but becomes a part of byte string literal
68 if let Some(next_char) = root.text().char_at(prev_token.text_range().end()) {
69 new_text.push(next_char);
70 let token_with_next_char = lex_single_syntax_kind(&new_text);
71 if let Some((_kind, _error)) = token_with_next_char {
72 return None;
73 }
74 new_text.pop();
75 }
76
77 let new_token =
78 GreenToken::new(rowan::SyntaxKind(prev_token_kind.into()), new_text.into());
79 Some((
80 prev_token.replace_with(new_token),
81 new_err.into_iter().collect(),
82 prev_token.text_range(),
83 ))
84 }
85 _ => None,
86 }
87}
88
89fn reparse_block<'node>(
90 root: &'node SyntaxNode,
91 edit: &Indel,
92) -> Option<(GreenNode, Vec<SyntaxError>, TextRange)> {
93 let (node, reparser) = find_reparsable_node(root, edit.delete)?;
94 let text = get_text_after_edit(node.clone().into(), edit);
95
96 let (tokens, new_lexer_errors) = tokenize(&text);
97 if !is_balanced(&tokens) {
98 return None;
99 }
100
101 let mut token_source = TextTokenSource::new(&text, &tokens);
102 let mut tree_sink = TextTreeSink::new(&text, &tokens);
103 reparser.parse(&mut token_source, &mut tree_sink);
104
105 let (green, mut new_parser_errors) = tree_sink.finish();
106 new_parser_errors.extend(new_lexer_errors);
107
108 Some((node.replace_with(green), new_parser_errors, node.text_range()))
109}
110
111fn get_text_after_edit(element: SyntaxElement, edit: &Indel) -> String {
112 let edit = Indel::replace(edit.delete - element.text_range().start(), edit.insert.clone());
113
114 let mut text = match element {
115 NodeOrToken::Token(token) => token.text().to_string(),
116 NodeOrToken::Node(node) => node.text().to_string(),
117 };
118 edit.apply(&mut text);
119 text
120}
121
122fn is_contextual_kw(text: &str) -> bool {
123 matches!(text, "auto" | "default" | "union")
124}
125
126fn find_reparsable_node(node: &SyntaxNode, range: TextRange) -> Option<(SyntaxNode, Reparser)> {
127 let node = algo::find_covering_element(node, range);
128
129 let mut ancestors = match node {
130 NodeOrToken::Token(it) => it.parent().ancestors(),
131 NodeOrToken::Node(it) => it.ancestors(),
132 };
133 ancestors.find_map(|node| {
134 let first_child = node.first_child_or_token().map(|it| it.kind());
135 let parent = node.parent().map(|it| it.kind());
136 Reparser::for_node(node.kind(), first_child, parent).map(|r| (node, r))
137 })
138}
139
140fn is_balanced(tokens: &[Token]) -> bool {
141 if tokens.is_empty()
142 || tokens.first().unwrap().kind != T!['{']
143 || tokens.last().unwrap().kind != T!['}']
144 {
145 return false;
146 }
147 let mut balance = 0usize;
148 for t in &tokens[1..tokens.len() - 1] {
149 match t.kind {
150 T!['{'] => balance += 1,
151 T!['}'] => {
152 balance = match balance.checked_sub(1) {
153 Some(b) => b,
154 None => return false,
155 }
156 }
157 _ => (),
158 }
159 }
160 balance == 0
161}
162
163fn merge_errors(
164 old_errors: Vec<SyntaxError>,
165 new_errors: Vec<SyntaxError>,
166 range_before_reparse: TextRange,
167 edit: &Indel,
168) -> Vec<SyntaxError> {
169 let mut res = Vec::new();
170
171 for old_err in old_errors {
172 let old_err_range = old_err.range();
173 if old_err_range.end() <= range_before_reparse.start() {
174 res.push(old_err);
175 } else if old_err_range.start() >= range_before_reparse.end() {
176 let inserted_len = TextSize::of(&edit.insert);
177 res.push(old_err.with_range((old_err_range + inserted_len) - edit.delete.len()));
178 // Note: extra parens are intentional to prevent uint underflow, HWAB (here was a bug)
179 }
180 }
181 res.extend(new_errors.into_iter().map(|new_err| {
182 // fighting borrow checker with a variable ;)
183 let offseted_range = new_err.range() + range_before_reparse.start();
184 new_err.with_range(offseted_range)
185 }));
186 res
187}
188
189#[cfg(test)]
190mod tests {
191 use test_utils::{assert_eq_text, extract_range};
192
193 use super::*;
194 use crate::{AstNode, Parse, SourceFile};
195
196 fn do_check(before: &str, replace_with: &str, reparsed_len: u32) {
197 let (range, before) = extract_range(before);
198 let edit = Indel::replace(range, replace_with.to_owned());
199 let after = {
200 let mut after = before.clone();
201 edit.apply(&mut after);
202 after
203 };
204
205 let fully_reparsed = SourceFile::parse(&after);
206 let incrementally_reparsed: Parse<SourceFile> = {
207 let before = SourceFile::parse(&before);
208 let (green, new_errors, range) =
209 incremental_reparse(before.tree().syntax(), &edit, before.errors.to_vec()).unwrap();
210 assert_eq!(range.len(), reparsed_len.into(), "reparsed fragment has wrong length");
211 Parse::new(green, new_errors)
212 };
213
214 assert_eq_text!(
215 &format!("{:#?}", fully_reparsed.tree().syntax()),
216 &format!("{:#?}", incrementally_reparsed.tree().syntax()),
217 );
218 assert_eq!(fully_reparsed.errors(), incrementally_reparsed.errors());
219 }
220
221 #[test] // FIXME: some test here actually test token reparsing
222 fn reparse_block_tests() {
223 do_check(
224 r"
225fn foo() {
226 let x = foo + <|>bar<|>
227}
228",
229 "baz",
230 3,
231 );
232 do_check(
233 r"
234fn foo() {
235 let x = foo<|> + bar<|>
236}
237",
238 "baz",
239 25,
240 );
241 do_check(
242 r"
243struct Foo {
244 f: foo<|><|>
245}
246",
247 ",\n g: (),",
248 14,
249 );
250 do_check(
251 r"
252fn foo {
253 let;
254 1 + 1;
255 <|>92<|>;
256}
257",
258 "62",
259 31, // FIXME: reparse only int literal here
260 );
261 do_check(
262 r"
263mod foo {
264 fn <|><|>
265}
266",
267 "bar",
268 11,
269 );
270
271 do_check(
272 r"
273trait Foo {
274 type <|>Foo<|>;
275}
276",
277 "Output",
278 3,
279 );
280 do_check(
281 r"
282impl IntoIterator<Item=i32> for Foo {
283 f<|><|>
284}
285",
286 "n next(",
287 9,
288 );
289 do_check(r"use a::b::{foo,<|>,bar<|>};", "baz", 10);
290 do_check(
291 r"
292pub enum A {
293 Foo<|><|>
294}
295",
296 "\nBar;\n",
297 11,
298 );
299 do_check(
300 r"
301foo!{a, b<|><|> d}
302",
303 ", c[3]",
304 8,
305 );
306 do_check(
307 r"
308fn foo() {
309 vec![<|><|>]
310}
311",
312 "123",
313 14,
314 );
315 do_check(
316 r"
317extern {
318 fn<|>;<|>
319}
320",
321 " exit(code: c_int)",
322 11,
323 );
324 }
325
326 #[test]
327 fn reparse_token_tests() {
328 do_check(
329 r"<|><|>
330fn foo() -> i32 { 1 }
331",
332 "\n\n\n \n",
333 1,
334 );
335 do_check(
336 r"
337fn foo() -> <|><|> {}
338",
339 " \n",
340 2,
341 );
342 do_check(
343 r"
344fn <|>foo<|>() -> i32 { 1 }
345",
346 "bar",
347 3,
348 );
349 do_check(
350 r"
351fn foo<|><|>foo() { }
352",
353 "bar",
354 6,
355 );
356 do_check(
357 r"
358fn foo /* <|><|> */ () {}
359",
360 "some comment",
361 6,
362 );
363 do_check(
364 r"
365fn baz <|><|> () {}
366",
367 " \t\t\n\n",
368 2,
369 );
370 do_check(
371 r"
372fn baz <|><|> () {}
373",
374 " \t\t\n\n",
375 2,
376 );
377 do_check(
378 r"
379/// foo <|><|>omment
380mod { }
381",
382 "c",
383 14,
384 );
385 do_check(
386 r#"
387fn -> &str { "Hello<|><|>" }
388"#,
389 ", world",
390 7,
391 );
392 do_check(
393 r#"
394fn -> &str { // "Hello<|><|>"
395"#,
396 ", world",
397 10,
398 );
399 do_check(
400 r##"
401fn -> &str { r#"Hello<|><|>"#
402"##,
403 ", world",
404 10,
405 );
406 do_check(
407 r"
408#[derive(<|>Copy<|>)]
409enum Foo {
410
411}
412",
413 "Clone",
414 4,
415 );
416 }
417
418 #[test]
419 fn reparse_str_token_with_error_unchanged() {
420 do_check(r#""<|>Unclosed<|> string literal"#, "Still unclosed", 24);
421 }
422
423 #[test]
424 fn reparse_str_token_with_error_fixed() {
425 do_check(r#""unterinated<|><|>"#, "\"", 12);
426 }
427
428 #[test]
429 fn reparse_block_with_error_in_middle_unchanged() {
430 do_check(
431 r#"fn main() {
432 if {}
433 32 + 4<|><|>
434 return
435 if {}
436 }"#,
437 "23",
438 105,
439 )
440 }
441
442 #[test]
443 fn reparse_block_with_error_in_middle_fixed() {
444 do_check(
445 r#"fn main() {
446 if {}
447 32 + 4<|><|>
448 return
449 if {}
450 }"#,
451 ";",
452 105,
453 )
454 }
455}
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