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 {
41 ModDeclaration(ast::Module),
42 // Original file ast node
44 receiver: Option<ast::Expr>,
47 // Original file ast node
49 receiver: Option<ast::Expr>,
50 receiver_is_ambiguous_float_literal: bool,
52 // Original file ast node
53 // Only set from a type arg
54 GenericArgList(ast::GenericArgList),
55 // Original file ast node
56 /// The record expr of the field name we are completing
57 RecordExpr(ast::RecordExpr),
58 // Original file ast node
59 /// The record pat of the field name we are completing
60 RecordPat(ast::RecordPat),
63 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
64 let node = match name_like {
65 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
66 ast::NameLike::Name(n) => n.syntax().clone(),
67 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
69 let node = match node.parent().and_then(ast::MacroCall::cast) {
70 // When a path is being typed after the name of a trait/type of an impl it is being
71 // parsed as a macro, so when the trait/impl has a block following it an we are between the
72 // name and block the macro will attach the block to itself so maximizing fails to take
74 // FIXME path expr and statement have a similar problem with attrs
76 if call.excl_token().is_none()
77 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
78 && call.semicolon_token().is_none() =>
84 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
85 if prev_sibling.kind() == ERROR {
86 let prev_sibling = prev_sibling.first_child()?;
87 let res = match_ast! {
89 // vis followed by random ident will always error the parser
90 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
96 let res = match_ast! {
98 ast::ExprStmt(it) => {
99 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
102 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
107 ast::Trait(it) => if it.assoc_item_list().is_none() {
108 ImmediatePrevSibling::TraitDefName
112 ast::Impl(it) => if it.assoc_item_list().is_none()
113 && (it.for_token().is_none() || it.self_ty().is_some()) {
114 ImmediatePrevSibling::ImplDefType
118 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
125 pub(crate) fn determine_location(
126 sema: &Semantics<RootDatabase>,
127 original_file: &SyntaxNode,
129 name_like: &ast::NameLike,
130 ) -> Option<ImmediateLocation> {
131 let node = match name_like {
132 ast::NameLike::NameRef(name_ref) => {
133 if ast::RecordExprField::for_field_name(name_ref).is_some() {
135 .find_node_at_offset_with_macros(original_file, offset)
136 .map(ImmediateLocation::RecordExpr);
138 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
140 .find_node_at_offset_with_macros(original_file, offset)
141 .map(ImmediateLocation::RecordPat);
143 maximize_name_ref(name_ref)
145 ast::NameLike::Name(name) => {
146 if ast::RecordPatField::for_field_name(name).is_some() {
148 .find_node_at_offset_with_macros(original_file, offset)
149 .map(ImmediateLocation::RecordPat);
151 name.syntax().clone()
153 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
156 let parent = match node.parent() {
157 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
158 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
159 // This is usually fine as the node expansion code above already accounts for that with
160 // the ancestors call, but there is one exception to this which is that when an attribute
161 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
162 // FIXME path expr and statement have a similar problem
164 if call.excl_token().is_none()
165 && call.token_tree().is_none()
166 && call.semicolon_token().is_none() =>
168 call.syntax().parent()?
174 return match node.kind() {
175 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
180 let res = match_ast! {
182 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
183 ast::Use(_it) => ImmediateLocation::Use,
184 ast::UseTree(_it) => ImmediateLocation::UseTree,
185 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
186 ast::BlockExpr(_it) => ImmediateLocation::BlockExpr,
187 ast::SourceFile(_it) => ImmediateLocation::ItemList,
188 ast::ItemList(_it) => ImmediateLocation::ItemList,
189 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
190 ast::RecordField(_it) => ImmediateLocation::RecordField,
191 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
192 Some(IMPL) => ImmediateLocation::Impl,
193 Some(TRAIT) => ImmediateLocation::Trait,
196 ast::GenericArgList(_it) => sema
197 .find_node_at_offset_with_macros(original_file, offset)
198 .map(ImmediateLocation::GenericArgList)?,
200 if it.item_list().is_none() {
201 ImmediateLocation::ModDeclaration(it)
206 ast::Attr(it) => ImmediateLocation::Attribute(it),
207 ast::FieldExpr(it) => {
210 .map(|e| e.syntax().text_range())
211 .and_then(|r| find_node_with_range(original_file, r));
212 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
214 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
220 ImmediateLocation::FieldAccess {
222 receiver_is_ambiguous_float_literal,
225 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
228 .map(|e| e.syntax().text_range())
229 .and_then(|r| find_node_with_range(original_file, r)),
230 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
238 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
239 // Maximize a nameref to its enclosing path if its the last segment of said path
240 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
241 let p = segment.parent_path();
242 if p.parent_path().is_none() {
246 .take_while(|it| it.text_range() == p.syntax().text_range())
253 name_ref.syntax().clone()
256 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
257 syntax.covering_element(range).ancestors().find_map(N::cast)
260 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
261 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
262 // where we only check the first parent with different text range.
265 .find(|it| it.kind() == IMPL)
266 .map(|it| ast::Impl::cast(it).unwrap())
267 .map(|it| it.trait_().is_some())
271 fn test_inside_impl_trait_block() {
272 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
273 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
274 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
275 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
278 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
279 element.into_token().and_then(previous_non_trivia_token)
282 /// Check if the token previous to the previous one is `for`.
283 /// For example, `for _ i$0` => true.
284 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
287 .and_then(previous_non_trivia_token)
288 .and_then(previous_non_trivia_token)
289 .filter(|it| it.kind() == T![for])
293 fn test_for_is_prev2() {
294 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
297 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
299 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
301 let loop_body = match_ast! {
303 ast::ForExpr(it) => it.loop_body(),
304 ast::WhileExpr(it) => it.loop_body(),
305 ast::LoopExpr(it) => it.loop_body(),
309 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
314 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
315 let mut token = token.prev_token();
316 while let Some(inner) = token.clone() {
317 if !inner.kind().is_trivia() {
320 token = inner.prev_token();
328 use syntax::algo::find_node_at_offset;
330 use crate::tests::position;
334 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
335 let (db, pos) = position(code);
337 let sema = Semantics::new(&db);
338 let original_file = sema.parse(pos.file_id);
340 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
342 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
347 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
348 check_pattern_is_applicable(code, |e| {
349 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
350 assert_eq!(determine_prev_sibling(name), sibling.into());
356 fn test_trait_loc() {
357 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
358 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
359 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
360 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
361 check_location(r"trait A$0 {}", None);
362 check_location(r"trait A { fn f$0 }", None);
367 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
368 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
369 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
370 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
371 check_location(r"impl A$0 {}", None);
372 check_location(r"impl A { fn f$0 }", None);
377 check_location(r"use f$0", ImmediateLocation::Use);
378 check_location(r"use f$0;", ImmediateLocation::Use);
379 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
380 check_location(r"use {f$0}", ImmediateLocation::UseTree);
384 fn test_record_field_loc() {
385 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
386 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
387 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
391 fn test_block_expr_loc() {
392 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
393 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::BlockExpr);
397 fn test_ident_pat_loc() {
398 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
399 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
400 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
401 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
405 fn test_ref_expr_loc() {
406 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
410 fn test_item_list_loc() {
411 check_location(r"i$0", ImmediateLocation::ItemList);
412 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
413 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
414 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
415 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
416 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
417 check_location(r"mod foo$0 {}", None);
421 fn test_impl_prev_sibling() {
422 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
423 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
424 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
425 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
426 check_prev_sibling(r"impl A for w$0 {}", None);
427 check_prev_sibling(r"impl A for w$0", None);
431 fn test_trait_prev_sibling() {
432 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
433 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
437 fn test_if_expr_prev_sibling() {
438 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
439 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
443 fn test_vis_prev_sibling() {
444 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
448 fn test_attr_prev_sibling() {
449 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);