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.
31 #[derive(Clone, Debug, PartialEq, Eq)]
32 pub(crate) enum ImmediateLocation {
48 ModDeclaration(ast::Module),
49 Visibility(ast::Visibility),
50 // Original file ast node
52 receiver: Option<ast::Expr>,
55 // Original file ast node
57 receiver: Option<ast::Expr>,
58 receiver_is_ambiguous_float_literal: bool,
60 // Original file ast node
61 // Only set from a type arg
62 GenericArgList(ast::GenericArgList),
63 // Original file ast node
64 /// The record expr of the field name we are completing
65 RecordExpr(ast::RecordExpr),
66 // Original file ast node
67 /// The record expr of the functional update syntax we are completing
68 RecordExprUpdate(ast::RecordExpr),
69 // Original file ast node
70 /// The record pat of the field name we are completing
71 RecordPat(ast::RecordPat),
74 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
75 let node = match name_like {
76 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
77 ast::NameLike::Name(n) => n.syntax().clone(),
78 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
80 let node = match node.parent().and_then(ast::MacroCall::cast) {
81 // When a path is being typed after the name of a trait/type of an impl it is being
82 // parsed as a macro, so when the trait/impl has a block following it an we are between the
83 // name and block the macro will attach the block to itself so maximizing fails to take
85 // FIXME path expr and statement have a similar problem with attrs
87 if call.excl_token().is_none()
88 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
89 && call.semicolon_token().is_none() =>
95 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
96 if prev_sibling.kind() == ERROR {
97 let prev_sibling = prev_sibling.first_child()?;
98 let res = match_ast! {
100 // vis followed by random ident will always error the parser
101 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
107 let res = match_ast! {
109 ast::ExprStmt(it) => {
110 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
113 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
118 ast::Trait(it) => if it.assoc_item_list().is_none() {
119 ImmediatePrevSibling::TraitDefName
123 ast::Impl(it) => if it.assoc_item_list().is_none()
124 && (it.for_token().is_none() || it.self_ty().is_some()) {
125 ImmediatePrevSibling::ImplDefType
129 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
136 pub(crate) fn determine_location(
137 sema: &Semantics<RootDatabase>,
138 original_file: &SyntaxNode,
140 name_like: &ast::NameLike,
141 ) -> Option<ImmediateLocation> {
142 let node = match name_like {
143 ast::NameLike::NameRef(name_ref) => {
144 if ast::RecordExprField::for_field_name(name_ref).is_some() {
146 .find_node_at_offset_with_macros(original_file, offset)
147 .map(ImmediateLocation::RecordExpr);
149 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
151 .find_node_at_offset_with_macros(original_file, offset)
152 .map(ImmediateLocation::RecordPat);
154 maximize_name_ref(name_ref)
156 ast::NameLike::Name(name) => {
157 if ast::RecordPatField::for_field_name(name).is_some() {
159 .find_node_at_offset_with_macros(original_file, offset)
160 .map(ImmediateLocation::RecordPat);
162 name.syntax().clone()
164 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
169 ast::TypeBoundList(_it) => return Some(ImmediateLocation::TypeBound),
174 let parent = match node.parent() {
175 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
176 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
177 // This is usually fine as the node expansion code above already accounts for that with
178 // the ancestors call, but there is one exception to this which is that when an attribute
179 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
180 // FIXME path expr and statement have a similar problem
182 if call.excl_token().is_none()
183 && call.token_tree().is_none()
184 && call.semicolon_token().is_none() =>
186 call.syntax().parent()?
192 return match node.kind() {
193 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
199 let res = match_ast! {
201 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
202 ast::Use(_it) => ImmediateLocation::Use,
203 ast::UseTree(_it) => ImmediateLocation::UseTree,
204 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
205 ast::Rename(_it) => ImmediateLocation::Rename,
206 ast::StmtList(_it) => ImmediateLocation::StmtList,
207 ast::SourceFile(_it) => ImmediateLocation::ItemList,
208 ast::ItemList(_it) => ImmediateLocation::ItemList,
209 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
210 ast::RecordField(it) => if it.ty().map_or(false, |it| it.syntax().text_range().contains(offset)) {
213 ImmediateLocation::RecordField
215 ast::RecordExprFieldList(_it) => sema
216 .find_node_at_offset_with_macros(original_file, offset)
217 .map(ImmediateLocation::RecordExprUpdate)?,
218 ast::TupleField(_it) => ImmediateLocation::TupleField,
219 ast::TupleFieldList(_it) => ImmediateLocation::TupleField,
220 ast::TypeBound(_it) => ImmediateLocation::TypeBound,
221 ast::TypeBoundList(_it) => ImmediateLocation::TypeBound,
222 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
223 Some(IMPL) => ImmediateLocation::Impl,
224 Some(TRAIT) => ImmediateLocation::Trait,
227 ast::GenericArgList(_it) => sema
228 .find_node_at_offset_with_macros(original_file, offset)
229 .map(ImmediateLocation::GenericArgList)?,
231 if it.item_list().is_none() {
232 ImmediateLocation::ModDeclaration(it)
237 ast::Attr(it) => ImmediateLocation::Attribute(it),
238 ast::FieldExpr(it) => {
241 .map(|e| e.syntax().text_range())
242 .and_then(|r| find_node_with_range(original_file, r));
243 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
245 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
251 ImmediateLocation::FieldAccess {
253 receiver_is_ambiguous_float_literal,
256 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
259 .map(|e| e.syntax().text_range())
260 .and_then(|r| find_node_with_range(original_file, r)),
261 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
263 ast::Visibility(it) => it.pub_token()
264 .and_then(|t| (t.text_range().end() < offset).then(|| ImmediateLocation::Visibility(it)))?,
271 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
272 // Maximize a nameref to its enclosing path if its the last segment of said path
273 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
274 let p = segment.parent_path();
275 if p.parent_path().is_none() {
279 .take_while(|it| it.text_range() == p.syntax().text_range())
286 name_ref.syntax().clone()
289 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
290 let range = syntax.text_range().intersect(range)?;
291 syntax.covering_element(range).ancestors().find_map(N::cast)
294 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
295 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
296 // where we only check the first parent with different text range.
299 .find(|it| it.kind() == IMPL)
300 .map(|it| ast::Impl::cast(it).unwrap())
301 .map(|it| it.trait_().is_some())
305 fn test_inside_impl_trait_block() {
306 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
307 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
308 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
309 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
312 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
313 element.into_token().and_then(previous_non_trivia_token)
316 /// Check if the token previous to the previous one is `for`.
317 /// For example, `for _ i$0` => true.
318 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
321 .and_then(previous_non_trivia_token)
322 .and_then(previous_non_trivia_token)
323 .filter(|it| it.kind() == T![for])
327 fn test_for_is_prev2() {
328 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
331 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
333 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
335 let loop_body = match_ast! {
337 ast::ForExpr(it) => it.loop_body(),
338 ast::WhileExpr(it) => it.loop_body(),
339 ast::LoopExpr(it) => it.loop_body(),
343 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
348 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
349 let mut token = token.prev_token();
350 while let Some(inner) = token.clone() {
351 if !inner.kind().is_trivia() {
354 token = inner.prev_token();
362 use syntax::algo::find_node_at_offset;
364 use crate::tests::position;
368 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
369 let (db, pos) = position(code);
371 let sema = Semantics::new(&db);
372 let original_file = sema.parse(pos.file_id);
374 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
376 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
381 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
382 check_pattern_is_applicable(code, |e| {
383 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
384 assert_eq!(determine_prev_sibling(name), sibling.into());
390 fn test_trait_loc() {
391 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
392 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
393 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
394 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
395 check_location(r"trait A$0 {}", None);
396 check_location(r"trait A { fn f$0 }", None);
401 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
402 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
403 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
404 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
405 check_location(r"impl A$0 {}", None);
406 check_location(r"impl A { fn f$0 }", None);
411 check_location(r"use f$0", ImmediateLocation::Use);
412 check_location(r"use f$0;", ImmediateLocation::Use);
413 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
414 check_location(r"use {f$0}", ImmediateLocation::UseTree);
418 fn test_record_field_loc() {
419 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
420 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
421 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
425 fn test_block_expr_loc() {
426 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::StmtList);
427 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::StmtList);
431 fn test_ident_pat_loc() {
432 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
433 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
434 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
435 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
439 fn test_ref_expr_loc() {
440 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
444 fn test_item_list_loc() {
445 check_location(r"i$0", ImmediateLocation::ItemList);
446 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
447 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
448 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
449 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
450 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
451 check_location(r"mod foo$0 {}", None);
455 fn test_impl_prev_sibling() {
456 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
457 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
458 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
459 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
460 check_prev_sibling(r"impl A for w$0 {}", None);
461 check_prev_sibling(r"impl A for w$0", None);
465 fn test_trait_prev_sibling() {
466 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
467 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
471 fn test_if_expr_prev_sibling() {
472 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
473 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
477 fn test_vis_prev_sibling() {
478 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
482 fn test_attr_prev_sibling() {
483 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);