1 //! Patterns telling us certain facts about current syntax element, they are used in completion context
3 //! Most logic in this module first expands the token below the cursor to a maximum node that acts similar to the token itself.
4 //! This means we for example expand a NameRef token to its outermost Path node, as semantically these act in the same location
5 //! and the completions usually query for path specific things on the Path context instead. This simplifies some location handling.
8 use ide_db::RootDatabase;
10 algo::non_trivia_sibling,
11 ast::{self, HasArgList, HasLoopBody},
12 match_ast, AstNode, Direction, SyntaxElement,
14 SyntaxNode, SyntaxToken, TextRange, TextSize, T,
18 use crate::tests::{check_pattern_is_applicable, check_pattern_is_not_applicable};
20 /// Immediate previous node to what we are completing.
21 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
22 pub(crate) enum ImmediatePrevSibling {
30 /// Direct parent "thing" of what we are currently completing.
32 /// This may contain nodes of the fake file as well as the original, comments on the variants specify
33 /// from which file the nodes are.
34 #[derive(Clone, Debug, PartialEq, Eq)]
35 pub(crate) enum ImmediateLocation {
49 /// Fake file ast node
51 /// Fake file ast node
52 ModDeclaration(ast::Module),
53 Visibility(ast::Visibility),
54 /// Original file ast node
56 receiver: Option<ast::Expr>,
59 /// Original file ast node
61 receiver: Option<ast::Expr>,
62 receiver_is_ambiguous_float_literal: bool,
64 // Only set from a type arg
65 /// Original file ast node
66 GenericArgList(ast::GenericArgList),
67 /// The record expr of the field name we are completing
69 /// Original file ast node
70 RecordExpr(ast::RecordExpr),
71 /// The record expr of the functional update syntax we are completing
73 /// Original file ast node
74 RecordExprUpdate(ast::RecordExpr),
75 /// The record pat of the field name we are completing
77 /// Original file ast node
78 RecordPat(ast::RecordPat),
81 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
82 let node = match name_like {
83 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
84 ast::NameLike::Name(n) => n.syntax().clone(),
85 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
87 let node = match node.parent().and_then(ast::MacroCall::cast) {
88 // When a path is being typed after the name of a trait/type of an impl it is being
89 // parsed as a macro, so when the trait/impl has a block following it an we are between the
90 // name and block the macro will attach the block to itself so maximizing fails to take
92 // FIXME path expr and statement have a similar problem with attrs
94 if call.excl_token().is_none()
95 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
96 && call.semicolon_token().is_none() =>
102 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
103 if prev_sibling.kind() == ERROR {
104 let prev_sibling = prev_sibling.first_child()?;
105 let res = match_ast! {
107 // vis followed by random ident will always error the parser
108 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
114 let res = match_ast! {
116 ast::ExprStmt(it) => {
117 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
120 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
125 ast::Trait(it) => if it.assoc_item_list().is_none() {
126 ImmediatePrevSibling::TraitDefName
130 ast::Impl(it) => if it.assoc_item_list().is_none()
131 && (it.for_token().is_none() || it.self_ty().is_some()) {
132 ImmediatePrevSibling::ImplDefType
136 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
143 pub(crate) fn determine_location(
144 sema: &Semantics<RootDatabase>,
145 original_file: &SyntaxNode,
147 name_like: &ast::NameLike,
148 ) -> Option<ImmediateLocation> {
149 let node = match name_like {
150 ast::NameLike::NameRef(name_ref) => {
151 if ast::RecordExprField::for_field_name(name_ref).is_some() {
153 .find_node_at_offset_with_macros(original_file, offset)
154 .map(ImmediateLocation::RecordExpr);
156 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
158 .find_node_at_offset_with_macros(original_file, offset)
159 .map(ImmediateLocation::RecordPat);
161 maximize_name_ref(name_ref)
163 ast::NameLike::Name(name) => {
164 if ast::RecordPatField::for_field_name(name).is_some() {
166 .find_node_at_offset_with_macros(original_file, offset)
167 .map(ImmediateLocation::RecordPat);
169 name.syntax().clone()
171 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
176 ast::TypeBoundList(_it) => return Some(ImmediateLocation::TypeBound),
181 let parent = match node.parent() {
182 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
183 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
184 // This is usually fine as the node expansion code above already accounts for that with
185 // the ancestors call, but there is one exception to this which is that when an attribute
186 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
187 // FIXME path expr and statement have a similar problem
189 if call.excl_token().is_none()
190 && call.token_tree().is_none()
191 && call.semicolon_token().is_none() =>
193 call.syntax().parent()?
199 return match node.kind() {
200 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
206 let res = match_ast! {
208 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
209 ast::Use(_it) => ImmediateLocation::Use,
210 ast::UseTree(_it) => ImmediateLocation::UseTree,
211 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
212 ast::Rename(_it) => ImmediateLocation::Rename,
213 ast::StmtList(_it) => ImmediateLocation::StmtList,
214 ast::SourceFile(_it) => ImmediateLocation::ItemList,
215 ast::ItemList(_it) => ImmediateLocation::ItemList,
216 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
217 ast::Variant(_it) => ImmediateLocation::Variant,
218 ast::RecordField(it) => if it.ty().map_or(false, |it| it.syntax().text_range().contains(offset)) {
221 ImmediateLocation::RecordField
223 ast::RecordExprFieldList(_it) => sema
224 .find_node_at_offset_with_macros(original_file, offset)
225 .map(ImmediateLocation::RecordExprUpdate)?,
226 ast::TupleField(_it) => ImmediateLocation::TupleField,
227 ast::TupleFieldList(_it) => ImmediateLocation::TupleField,
228 ast::TypeBound(_it) => ImmediateLocation::TypeBound,
229 ast::TypeBoundList(_it) => ImmediateLocation::TypeBound,
230 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
231 Some(IMPL) => ImmediateLocation::Impl,
232 Some(TRAIT) => ImmediateLocation::Trait,
235 ast::GenericArgList(_it) => sema
236 .find_node_at_offset_with_macros(original_file, offset)
237 .map(ImmediateLocation::GenericArgList)?,
239 if it.item_list().is_none() {
240 ImmediateLocation::ModDeclaration(it)
245 ast::Attr(it) => ImmediateLocation::Attribute(it),
246 ast::FieldExpr(it) => {
249 .map(|e| e.syntax().text_range())
250 .and_then(|r| find_node_with_range(original_file, r));
251 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
253 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
259 ImmediateLocation::FieldAccess {
261 receiver_is_ambiguous_float_literal,
264 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
267 .map(|e| e.syntax().text_range())
268 .and_then(|r| find_node_with_range(original_file, r)),
269 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
271 ast::Visibility(it) => it.pub_token()
272 .and_then(|t| (t.text_range().end() < offset).then(|| ImmediateLocation::Visibility(it)))?,
279 /// Maximize a nameref to its enclosing path if its the last segment of said path.
280 /// That is, when completing a [`NameRef`] we actually handle it as the path it is part of when determining
282 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
283 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
284 let p = segment.parent_path();
285 if p.parent_path().is_none() {
286 // Get rid of PathExpr, PathType, etc...
290 .take_while(|it| it.text_range() == p.syntax().text_range())
292 if let Some(it) = path {
297 name_ref.syntax().clone()
300 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
301 let range = syntax.text_range().intersect(range)?;
302 syntax.covering_element(range).ancestors().find_map(N::cast)
305 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
306 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
307 // where we only check the first parent with different text range.
310 .find(|it| it.kind() == IMPL)
311 .map(|it| ast::Impl::cast(it).unwrap())
312 .map(|it| it.trait_().is_some())
316 fn test_inside_impl_trait_block() {
317 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
318 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
319 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
320 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
323 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
324 element.into_token().and_then(previous_non_trivia_token)
327 /// Check if the token previous to the previous one is `for`.
328 /// For example, `for _ i$0` => true.
329 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
332 .and_then(previous_non_trivia_token)
333 .and_then(previous_non_trivia_token)
334 .filter(|it| it.kind() == T![for])
338 fn test_for_is_prev2() {
339 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
342 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
344 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
346 let loop_body = match_ast! {
348 ast::ForExpr(it) => it.loop_body(),
349 ast::WhileExpr(it) => it.loop_body(),
350 ast::LoopExpr(it) => it.loop_body(),
354 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
359 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
360 let mut token = token.prev_token();
361 while let Some(inner) = token.clone() {
362 if !inner.kind().is_trivia() {
365 token = inner.prev_token();
373 use syntax::algo::find_node_at_offset;
375 use crate::tests::position;
379 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
380 let (db, pos) = position(code);
382 let sema = Semantics::new(&db);
383 let original_file = sema.parse(pos.file_id);
385 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
387 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
392 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
393 check_pattern_is_applicable(code, |e| {
394 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
395 assert_eq!(determine_prev_sibling(name), sibling.into());
401 fn test_trait_loc() {
402 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
403 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
404 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
405 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
406 check_location(r"trait A$0 {}", None);
407 check_location(r"trait A { fn f$0 }", None);
412 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
413 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
414 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
415 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
416 check_location(r"impl A$0 {}", None);
417 check_location(r"impl A { fn f$0 }", None);
422 check_location(r"use f$0", ImmediateLocation::Use);
423 check_location(r"use f$0;", ImmediateLocation::Use);
424 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
425 check_location(r"use {f$0}", ImmediateLocation::UseTree);
429 fn test_record_field_loc() {
430 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
431 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
432 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
436 fn test_block_expr_loc() {
437 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::StmtList);
438 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::StmtList);
442 fn test_ident_pat_loc() {
443 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
444 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
445 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
446 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
450 fn test_ref_expr_loc() {
451 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
455 fn test_item_list_loc() {
456 check_location(r"i$0", ImmediateLocation::ItemList);
457 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
458 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
459 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
460 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
461 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
462 check_location(r"mod foo$0 {}", None);
466 fn test_impl_prev_sibling() {
467 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
468 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
469 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
470 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
471 check_prev_sibling(r"impl A for w$0 {}", None);
472 check_prev_sibling(r"impl A for w$0", None);
476 fn test_trait_prev_sibling() {
477 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
478 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
482 fn test_if_expr_prev_sibling() {
483 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
484 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
488 fn test_vis_prev_sibling() {
489 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
493 fn test_attr_prev_sibling() {
494 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);