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, ArgListOwner, LoopBodyOwner},
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 {
47 ModDeclaration(ast::Module),
48 Visibility(ast::Visibility),
49 // Original file ast node
51 receiver: Option<ast::Expr>,
54 // Original file ast node
56 receiver: Option<ast::Expr>,
57 receiver_is_ambiguous_float_literal: bool,
59 // Original file ast node
60 // Only set from a type arg
61 GenericArgList(ast::GenericArgList),
62 // Original file ast node
63 /// The record expr of the field name we are completing
64 RecordExpr(ast::RecordExpr),
65 // Original file ast node
66 /// The record pat of the field name we are completing
67 RecordPat(ast::RecordPat),
70 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
71 let node = match name_like {
72 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
73 ast::NameLike::Name(n) => n.syntax().clone(),
74 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
76 let node = match node.parent().and_then(ast::MacroCall::cast) {
77 // When a path is being typed after the name of a trait/type of an impl it is being
78 // parsed as a macro, so when the trait/impl has a block following it an we are between the
79 // name and block the macro will attach the block to itself so maximizing fails to take
81 // FIXME path expr and statement have a similar problem with attrs
83 if call.excl_token().is_none()
84 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
85 && call.semicolon_token().is_none() =>
91 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
92 if prev_sibling.kind() == ERROR {
93 let prev_sibling = prev_sibling.first_child()?;
94 let res = match_ast! {
96 // vis followed by random ident will always error the parser
97 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
103 let res = match_ast! {
105 ast::ExprStmt(it) => {
106 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
109 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
114 ast::Trait(it) => if it.assoc_item_list().is_none() {
115 ImmediatePrevSibling::TraitDefName
119 ast::Impl(it) => if it.assoc_item_list().is_none()
120 && (it.for_token().is_none() || it.self_ty().is_some()) {
121 ImmediatePrevSibling::ImplDefType
125 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
132 pub(crate) fn determine_location(
133 sema: &Semantics<RootDatabase>,
134 original_file: &SyntaxNode,
136 name_like: &ast::NameLike,
137 ) -> Option<ImmediateLocation> {
138 let node = match name_like {
139 ast::NameLike::NameRef(name_ref) => {
140 if ast::RecordExprField::for_field_name(name_ref).is_some() {
142 .find_node_at_offset_with_macros(original_file, offset)
143 .map(ImmediateLocation::RecordExpr);
145 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
147 .find_node_at_offset_with_macros(original_file, offset)
148 .map(ImmediateLocation::RecordPat);
150 maximize_name_ref(name_ref)
152 ast::NameLike::Name(name) => {
153 if ast::RecordPatField::for_field_name(name).is_some() {
155 .find_node_at_offset_with_macros(original_file, offset)
156 .map(ImmediateLocation::RecordPat);
158 name.syntax().clone()
160 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
165 ast::TypeBoundList(_it) => return Some(ImmediateLocation::TypeBound),
170 let parent = match node.parent() {
171 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
172 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
173 // This is usually fine as the node expansion code above already accounts for that with
174 // the ancestors call, but there is one exception to this which is that when an attribute
175 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
176 // FIXME path expr and statement have a similar problem
178 if call.excl_token().is_none()
179 && call.token_tree().is_none()
180 && call.semicolon_token().is_none() =>
182 call.syntax().parent()?
188 return match node.kind() {
189 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
195 let res = match_ast! {
197 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
198 ast::Use(_it) => ImmediateLocation::Use,
199 ast::UseTree(_it) => ImmediateLocation::UseTree,
200 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
201 ast::BlockExpr(_it) => ImmediateLocation::BlockExpr,
202 ast::SourceFile(_it) => ImmediateLocation::ItemList,
203 ast::ItemList(_it) => ImmediateLocation::ItemList,
204 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
205 ast::RecordField(it) => if it.ty().map_or(false, |it| it.syntax().text_range().contains(offset)) {
208 ImmediateLocation::RecordField
210 ast::RecordExprFieldList(_it) => sema
211 .find_node_at_offset_with_macros(original_file, offset)
212 .map(ImmediateLocation::RecordExpr)?,
213 ast::TupleField(_it) => ImmediateLocation::TupleField,
214 ast::TupleFieldList(_it) => ImmediateLocation::TupleField,
215 ast::TypeBound(_it) => ImmediateLocation::TypeBound,
216 ast::TypeBoundList(_it) => ImmediateLocation::TypeBound,
217 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
218 Some(IMPL) => ImmediateLocation::Impl,
219 Some(TRAIT) => ImmediateLocation::Trait,
222 ast::GenericArgList(_it) => sema
223 .find_node_at_offset_with_macros(original_file, offset)
224 .map(ImmediateLocation::GenericArgList)?,
226 if it.item_list().is_none() {
227 ImmediateLocation::ModDeclaration(it)
232 ast::Attr(it) => ImmediateLocation::Attribute(it),
233 ast::FieldExpr(it) => {
236 .map(|e| e.syntax().text_range())
237 .and_then(|r| find_node_with_range(original_file, r));
238 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
240 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
246 ImmediateLocation::FieldAccess {
248 receiver_is_ambiguous_float_literal,
251 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
254 .map(|e| e.syntax().text_range())
255 .and_then(|r| find_node_with_range(original_file, r)),
256 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
258 ast::Visibility(it) => it.pub_token()
259 .and_then(|t| (t.text_range().end() < offset).then(|| ImmediateLocation::Visibility(it)))?,
266 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
267 // Maximize a nameref to its enclosing path if its the last segment of said path
268 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
269 let p = segment.parent_path();
270 if p.parent_path().is_none() {
274 .take_while(|it| it.text_range() == p.syntax().text_range())
281 name_ref.syntax().clone()
284 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
285 syntax.covering_element(range).ancestors().find_map(N::cast)
288 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
289 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
290 // where we only check the first parent with different text range.
293 .find(|it| it.kind() == IMPL)
294 .map(|it| ast::Impl::cast(it).unwrap())
295 .map(|it| it.trait_().is_some())
299 fn test_inside_impl_trait_block() {
300 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
301 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
302 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
303 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
306 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
307 element.into_token().and_then(previous_non_trivia_token)
310 /// Check if the token previous to the previous one is `for`.
311 /// For example, `for _ i$0` => true.
312 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
315 .and_then(previous_non_trivia_token)
316 .and_then(previous_non_trivia_token)
317 .filter(|it| it.kind() == T![for])
321 fn test_for_is_prev2() {
322 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
325 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
327 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
329 let loop_body = match_ast! {
331 ast::ForExpr(it) => it.loop_body(),
332 ast::WhileExpr(it) => it.loop_body(),
333 ast::LoopExpr(it) => it.loop_body(),
337 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
342 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
343 let mut token = token.prev_token();
344 while let Some(inner) = token.clone() {
345 if !inner.kind().is_trivia() {
348 token = inner.prev_token();
356 use syntax::algo::find_node_at_offset;
358 use crate::tests::position;
362 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
363 let (db, pos) = position(code);
365 let sema = Semantics::new(&db);
366 let original_file = sema.parse(pos.file_id);
368 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
370 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
375 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
376 check_pattern_is_applicable(code, |e| {
377 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
378 assert_eq!(determine_prev_sibling(name), sibling.into());
384 fn test_trait_loc() {
385 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
386 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
387 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
388 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
389 check_location(r"trait A$0 {}", None);
390 check_location(r"trait A { fn f$0 }", None);
395 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
396 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
397 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
398 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
399 check_location(r"impl A$0 {}", None);
400 check_location(r"impl A { fn f$0 }", None);
405 check_location(r"use f$0", ImmediateLocation::Use);
406 check_location(r"use f$0;", ImmediateLocation::Use);
407 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
408 check_location(r"use {f$0}", ImmediateLocation::UseTree);
412 fn test_record_field_loc() {
413 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
414 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
415 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
419 fn test_block_expr_loc() {
420 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
421 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::BlockExpr);
425 fn test_ident_pat_loc() {
426 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
427 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
428 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
429 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
433 fn test_ref_expr_loc() {
434 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
438 fn test_item_list_loc() {
439 check_location(r"i$0", ImmediateLocation::ItemList);
440 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
441 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
442 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
443 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
444 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
445 check_location(r"mod foo$0 {}", None);
449 fn test_impl_prev_sibling() {
450 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
451 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
452 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
453 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
454 check_prev_sibling(r"impl A for w$0 {}", None);
455 check_prev_sibling(r"impl A for w$0", None);
459 fn test_trait_prev_sibling() {
460 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
461 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
465 fn test_if_expr_prev_sibling() {
466 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
467 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
471 fn test_vis_prev_sibling() {
472 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
476 fn test_attr_prev_sibling() {
477 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);