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 {
48 /// Fake file ast node
50 /// Fake file ast node
51 ModDeclaration(ast::Module),
52 Visibility(ast::Visibility),
53 /// Original file ast node
55 receiver: Option<ast::Expr>,
58 /// Original file ast node
60 receiver: Option<ast::Expr>,
61 receiver_is_ambiguous_float_literal: bool,
63 // Only set from a type arg
64 /// Original file ast node
65 GenericArgList(ast::GenericArgList),
66 /// The record expr of the field name we are completing
68 /// Original file ast node
69 RecordExpr(ast::RecordExpr),
70 /// The record expr of the functional update syntax we are completing
72 /// Original file ast node
73 RecordExprUpdate(ast::RecordExpr),
74 /// The record pat of the field name we are completing
76 /// Original file ast node
77 RecordPat(ast::RecordPat),
80 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
81 let node = match name_like {
82 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
83 ast::NameLike::Name(n) => n.syntax().clone(),
84 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
86 let node = match node.parent().and_then(ast::MacroCall::cast) {
87 // When a path is being typed after the name of a trait/type of an impl it is being
88 // parsed as a macro, so when the trait/impl has a block following it an we are between the
89 // name and block the macro will attach the block to itself so maximizing fails to take
91 // FIXME path expr and statement have a similar problem with attrs
93 if call.excl_token().is_none()
94 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
95 && call.semicolon_token().is_none() =>
101 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
102 if prev_sibling.kind() == ERROR {
103 let prev_sibling = prev_sibling.first_child()?;
104 let res = match_ast! {
106 // vis followed by random ident will always error the parser
107 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
113 let res = match_ast! {
115 ast::ExprStmt(it) => {
116 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
119 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
124 ast::Trait(it) => if it.assoc_item_list().is_none() {
125 ImmediatePrevSibling::TraitDefName
129 ast::Impl(it) => if it.assoc_item_list().is_none()
130 && (it.for_token().is_none() || it.self_ty().is_some()) {
131 ImmediatePrevSibling::ImplDefType
135 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
142 pub(crate) fn determine_location(
143 sema: &Semantics<RootDatabase>,
144 original_file: &SyntaxNode,
146 name_like: &ast::NameLike,
147 ) -> Option<ImmediateLocation> {
148 let node = match name_like {
149 ast::NameLike::NameRef(name_ref) => {
150 if ast::RecordExprField::for_field_name(name_ref).is_some() {
152 .find_node_at_offset_with_macros(original_file, offset)
153 .map(ImmediateLocation::RecordExpr);
155 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
157 .find_node_at_offset_with_macros(original_file, offset)
158 .map(ImmediateLocation::RecordPat);
160 maximize_name_ref(name_ref)
162 ast::NameLike::Name(name) => {
163 if ast::RecordPatField::for_field_name(name).is_some() {
165 .find_node_at_offset_with_macros(original_file, offset)
166 .map(ImmediateLocation::RecordPat);
168 name.syntax().clone()
170 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
175 ast::TypeBoundList(_it) => return Some(ImmediateLocation::TypeBound),
180 let parent = match node.parent() {
181 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
182 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
183 // This is usually fine as the node expansion code above already accounts for that with
184 // the ancestors call, but there is one exception to this which is that when an attribute
185 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
186 // FIXME path expr and statement have a similar problem
188 if call.excl_token().is_none()
189 && call.token_tree().is_none()
190 && call.semicolon_token().is_none() =>
192 call.syntax().parent()?
198 return match node.kind() {
199 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
205 let res = match_ast! {
207 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
208 ast::Use(_it) => ImmediateLocation::Use,
209 ast::UseTree(_it) => ImmediateLocation::UseTree,
210 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
211 ast::Rename(_it) => ImmediateLocation::Rename,
212 ast::StmtList(_it) => ImmediateLocation::StmtList,
213 ast::SourceFile(_it) => ImmediateLocation::ItemList,
214 ast::ItemList(_it) => ImmediateLocation::ItemList,
215 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
216 ast::RecordField(it) => if it.ty().map_or(false, |it| it.syntax().text_range().contains(offset)) {
219 ImmediateLocation::RecordField
221 ast::RecordExprFieldList(_it) => sema
222 .find_node_at_offset_with_macros(original_file, offset)
223 .map(ImmediateLocation::RecordExprUpdate)?,
224 ast::TupleField(_it) => ImmediateLocation::TupleField,
225 ast::TupleFieldList(_it) => ImmediateLocation::TupleField,
226 ast::TypeBound(_it) => ImmediateLocation::TypeBound,
227 ast::TypeBoundList(_it) => ImmediateLocation::TypeBound,
228 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
229 Some(IMPL) => ImmediateLocation::Impl,
230 Some(TRAIT) => ImmediateLocation::Trait,
233 ast::GenericArgList(_it) => sema
234 .find_node_at_offset_with_macros(original_file, offset)
235 .map(ImmediateLocation::GenericArgList)?,
237 if it.item_list().is_none() {
238 ImmediateLocation::ModDeclaration(it)
243 ast::Attr(it) => ImmediateLocation::Attribute(it),
244 ast::FieldExpr(it) => {
247 .map(|e| e.syntax().text_range())
248 .and_then(|r| find_node_with_range(original_file, r));
249 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
251 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
257 ImmediateLocation::FieldAccess {
259 receiver_is_ambiguous_float_literal,
262 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
265 .map(|e| e.syntax().text_range())
266 .and_then(|r| find_node_with_range(original_file, r)),
267 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
269 ast::Visibility(it) => it.pub_token()
270 .and_then(|t| (t.text_range().end() < offset).then(|| ImmediateLocation::Visibility(it)))?,
277 /// Maximize a nameref to its enclosing path if its the last segment of said path.
278 /// That is, when completing a [`NameRef`] we actually handle it as the path it is part of when determining
280 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
281 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
282 let p = segment.parent_path();
283 if p.parent_path().is_none() {
284 // Get rid of PathExpr, PathType, etc...
288 .take_while(|it| it.text_range() == p.syntax().text_range())
290 if let Some(it) = path {
295 name_ref.syntax().clone()
298 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
299 let range = syntax.text_range().intersect(range)?;
300 syntax.covering_element(range).ancestors().find_map(N::cast)
303 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
304 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
305 // where we only check the first parent with different text range.
308 .find(|it| it.kind() == IMPL)
309 .map(|it| ast::Impl::cast(it).unwrap())
310 .map(|it| it.trait_().is_some())
314 fn test_inside_impl_trait_block() {
315 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
316 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
317 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
318 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
321 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
322 element.into_token().and_then(previous_non_trivia_token)
325 /// Check if the token previous to the previous one is `for`.
326 /// For example, `for _ i$0` => true.
327 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
330 .and_then(previous_non_trivia_token)
331 .and_then(previous_non_trivia_token)
332 .filter(|it| it.kind() == T![for])
336 fn test_for_is_prev2() {
337 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
340 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
342 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
344 let loop_body = match_ast! {
346 ast::ForExpr(it) => it.loop_body(),
347 ast::WhileExpr(it) => it.loop_body(),
348 ast::LoopExpr(it) => it.loop_body(),
352 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
357 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
358 let mut token = token.prev_token();
359 while let Some(inner) = token.clone() {
360 if !inner.kind().is_trivia() {
363 token = inner.prev_token();
371 use syntax::algo::find_node_at_offset;
373 use crate::tests::position;
377 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
378 let (db, pos) = position(code);
380 let sema = Semantics::new(&db);
381 let original_file = sema.parse(pos.file_id);
383 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
385 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
390 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
391 check_pattern_is_applicable(code, |e| {
392 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
393 assert_eq!(determine_prev_sibling(name), sibling.into());
399 fn test_trait_loc() {
400 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
401 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
402 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
403 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
404 check_location(r"trait A$0 {}", None);
405 check_location(r"trait A { fn f$0 }", None);
410 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
411 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
412 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
413 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
414 check_location(r"impl A$0 {}", None);
415 check_location(r"impl A { fn f$0 }", None);
420 check_location(r"use f$0", ImmediateLocation::Use);
421 check_location(r"use f$0;", ImmediateLocation::Use);
422 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
423 check_location(r"use {f$0}", ImmediateLocation::UseTree);
427 fn test_record_field_loc() {
428 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
429 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
430 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
434 fn test_block_expr_loc() {
435 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::StmtList);
436 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::StmtList);
440 fn test_ident_pat_loc() {
441 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
442 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
443 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
444 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
448 fn test_ref_expr_loc() {
449 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
453 fn test_item_list_loc() {
454 check_location(r"i$0", ImmediateLocation::ItemList);
455 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
456 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
457 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
458 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
459 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
460 check_location(r"mod foo$0 {}", None);
464 fn test_impl_prev_sibling() {
465 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
466 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
467 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
468 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
469 check_prev_sibling(r"impl A for w$0 {}", None);
470 check_prev_sibling(r"impl A for w$0", None);
474 fn test_trait_prev_sibling() {
475 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
476 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
480 fn test_if_expr_prev_sibling() {
481 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
482 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
486 fn test_vis_prev_sibling() {
487 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
491 fn test_attr_prev_sibling() {
492 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);