1 //! Patterns telling us certain facts about current syntax element, they are used in completion context
4 use ide_db::RootDatabase;
6 algo::non_trivia_sibling,
7 ast::{self, ArgListOwner, LoopBodyOwner},
8 match_ast, AstNode, Direction, SyntaxElement,
10 SyntaxNode, SyntaxToken, TextRange, TextSize, T,
14 use crate::tests::{check_pattern_is_applicable, check_pattern_is_not_applicable};
16 /// Immediate previous node to what we are completing.
17 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
18 pub(crate) enum ImmediatePrevSibling {
26 /// Direct parent "thing" of what we are currently completing.
27 #[derive(Clone, Debug, PartialEq, Eq)]
28 pub(crate) enum ImmediateLocation {
42 ModDeclaration(ast::Module),
43 // Original file ast node
45 receiver: Option<ast::Expr>,
48 // Original file ast node
50 receiver: Option<ast::Expr>,
51 receiver_is_ambiguous_float_literal: bool,
53 // Original file ast node
54 // Only set from a type arg
55 GenericArgList(ast::GenericArgList),
56 // Original file ast node
57 /// The record expr of the field name we are completing
58 RecordExpr(ast::RecordExpr),
59 // Original file ast node
60 /// The record pat of the field name we are completing
61 RecordPat(ast::RecordPat),
64 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
65 let node = match name_like {
66 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
67 ast::NameLike::Name(n) => n.syntax().clone(),
68 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
70 let node = match node.parent().and_then(ast::MacroCall::cast) {
71 // When a path is being typed after the name of a trait/type of an impl it is being
72 // parsed as a macro, so when the trait/impl has a block following it an we are between the
73 // name and block the macro will attach the block to itself so maximizing fails to take
75 // FIXME path expr and statement have a similar problem with attrs
77 if call.excl_token().is_none()
78 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
79 && call.semicolon_token().is_none() =>
85 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
86 if prev_sibling.kind() == ERROR {
87 let prev_sibling = prev_sibling.first_child()?;
88 let res = match_ast! {
90 // vis followed by random ident will always error the parser
91 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
97 let res = match_ast! {
99 ast::ExprStmt(it) => {
100 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
103 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
108 ast::Trait(it) => if it.assoc_item_list().is_none() {
109 ImmediatePrevSibling::TraitDefName
113 ast::Impl(it) => if it.assoc_item_list().is_none()
114 && (it.for_token().is_none() || it.self_ty().is_some()) {
115 ImmediatePrevSibling::ImplDefType
119 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
126 pub(crate) fn determine_location(
127 sema: &Semantics<RootDatabase>,
128 original_file: &SyntaxNode,
130 name_like: &ast::NameLike,
131 ) -> Option<ImmediateLocation> {
132 let node = match name_like {
133 ast::NameLike::NameRef(name_ref) => {
134 if ast::RecordExprField::for_field_name(name_ref).is_some() {
136 .find_node_at_offset_with_macros(original_file, offset)
137 .map(ImmediateLocation::RecordExpr);
139 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
141 .find_node_at_offset_with_macros(original_file, offset)
142 .map(ImmediateLocation::RecordPat);
144 maximize_name_ref(name_ref)
146 ast::NameLike::Name(name) => {
147 if ast::RecordPatField::for_field_name(name).is_some() {
149 .find_node_at_offset_with_macros(original_file, offset)
150 .map(ImmediateLocation::RecordPat);
152 name.syntax().clone()
154 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
157 let parent = match node.parent() {
158 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
159 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
160 // This is usually fine as the node expansion code above already accounts for that with
161 // the ancestors call, but there is one exception to this which is that when an attribute
162 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
163 // FIXME path expr and statement have a similar problem
165 if call.excl_token().is_none()
166 && call.token_tree().is_none()
167 && call.semicolon_token().is_none() =>
169 call.syntax().parent()?
175 return match node.kind() {
176 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
181 let res = match_ast! {
183 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
184 ast::Use(_it) => ImmediateLocation::Use,
185 ast::UseTree(_it) => ImmediateLocation::UseTree,
186 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
187 ast::BlockExpr(_it) => ImmediateLocation::BlockExpr,
188 ast::SourceFile(_it) => ImmediateLocation::ItemList,
189 ast::ItemList(_it) => ImmediateLocation::ItemList,
190 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
191 ast::RecordField(it) => if it.ty().map_or(false, |it| it.syntax().text_range().contains(offset)) {
194 ImmediateLocation::RecordField
196 ast::TupleField(_it) => ImmediateLocation::TupleField,
197 ast::TupleFieldList(_it) => ImmediateLocation::TupleField,
198 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
199 Some(IMPL) => ImmediateLocation::Impl,
200 Some(TRAIT) => ImmediateLocation::Trait,
203 ast::GenericArgList(_it) => sema
204 .find_node_at_offset_with_macros(original_file, offset)
205 .map(ImmediateLocation::GenericArgList)?,
207 if it.item_list().is_none() {
208 ImmediateLocation::ModDeclaration(it)
213 ast::Attr(it) => ImmediateLocation::Attribute(it),
214 ast::FieldExpr(it) => {
217 .map(|e| e.syntax().text_range())
218 .and_then(|r| find_node_with_range(original_file, r));
219 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
221 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
227 ImmediateLocation::FieldAccess {
229 receiver_is_ambiguous_float_literal,
232 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
235 .map(|e| e.syntax().text_range())
236 .and_then(|r| find_node_with_range(original_file, r)),
237 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
245 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
246 // Maximize a nameref to its enclosing path if its the last segment of said path
247 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
248 let p = segment.parent_path();
249 if p.parent_path().is_none() {
253 .take_while(|it| it.text_range() == p.syntax().text_range())
260 name_ref.syntax().clone()
263 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
264 syntax.covering_element(range).ancestors().find_map(N::cast)
267 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
268 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
269 // where we only check the first parent with different text range.
272 .find(|it| it.kind() == IMPL)
273 .map(|it| ast::Impl::cast(it).unwrap())
274 .map(|it| it.trait_().is_some())
278 fn test_inside_impl_trait_block() {
279 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
280 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
281 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
282 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
285 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
286 element.into_token().and_then(previous_non_trivia_token)
289 /// Check if the token previous to the previous one is `for`.
290 /// For example, `for _ i$0` => true.
291 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
294 .and_then(previous_non_trivia_token)
295 .and_then(previous_non_trivia_token)
296 .filter(|it| it.kind() == T![for])
300 fn test_for_is_prev2() {
301 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
304 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
306 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
308 let loop_body = match_ast! {
310 ast::ForExpr(it) => it.loop_body(),
311 ast::WhileExpr(it) => it.loop_body(),
312 ast::LoopExpr(it) => it.loop_body(),
316 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
321 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
322 let mut token = token.prev_token();
323 while let Some(inner) = token.clone() {
324 if !inner.kind().is_trivia() {
327 token = inner.prev_token();
335 use syntax::algo::find_node_at_offset;
337 use crate::tests::position;
341 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
342 let (db, pos) = position(code);
344 let sema = Semantics::new(&db);
345 let original_file = sema.parse(pos.file_id);
347 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
349 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
354 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
355 check_pattern_is_applicable(code, |e| {
356 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
357 assert_eq!(determine_prev_sibling(name), sibling.into());
363 fn test_trait_loc() {
364 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
365 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
366 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
367 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
368 check_location(r"trait A$0 {}", None);
369 check_location(r"trait A { fn f$0 }", None);
374 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
375 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
376 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
377 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
378 check_location(r"impl A$0 {}", None);
379 check_location(r"impl A { fn f$0 }", None);
384 check_location(r"use f$0", ImmediateLocation::Use);
385 check_location(r"use f$0;", ImmediateLocation::Use);
386 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
387 check_location(r"use {f$0}", ImmediateLocation::UseTree);
391 fn test_record_field_loc() {
392 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
393 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
394 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
398 fn test_block_expr_loc() {
399 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
400 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::BlockExpr);
404 fn test_ident_pat_loc() {
405 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
406 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
407 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
408 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
412 fn test_ref_expr_loc() {
413 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
417 fn test_item_list_loc() {
418 check_location(r"i$0", ImmediateLocation::ItemList);
419 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
420 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
421 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
422 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
423 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
424 check_location(r"mod foo$0 {}", None);
428 fn test_impl_prev_sibling() {
429 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
430 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
431 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
432 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
433 check_prev_sibling(r"impl A for w$0 {}", None);
434 check_prev_sibling(r"impl A for w$0", None);
438 fn test_trait_prev_sibling() {
439 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
440 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
444 fn test_if_expr_prev_sibling() {
445 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
446 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
450 fn test_vis_prev_sibling() {
451 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
455 fn test_attr_prev_sibling() {
456 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);