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 expr of the functional update syntax we are completing
67 RecordExprUpdate(ast::RecordExpr),
68 // Original file ast node
69 /// The record pat of the field name we are completing
70 RecordPat(ast::RecordPat),
73 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
74 let node = match name_like {
75 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
76 ast::NameLike::Name(n) => n.syntax().clone(),
77 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
79 let node = match node.parent().and_then(ast::MacroCall::cast) {
80 // When a path is being typed after the name of a trait/type of an impl it is being
81 // parsed as a macro, so when the trait/impl has a block following it an we are between the
82 // name and block the macro will attach the block to itself so maximizing fails to take
84 // FIXME path expr and statement have a similar problem with attrs
86 if call.excl_token().is_none()
87 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
88 && call.semicolon_token().is_none() =>
94 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
95 if prev_sibling.kind() == ERROR {
96 let prev_sibling = prev_sibling.first_child()?;
97 let res = match_ast! {
99 // vis followed by random ident will always error the parser
100 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
106 let res = match_ast! {
108 ast::ExprStmt(it) => {
109 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
112 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
117 ast::Trait(it) => if it.assoc_item_list().is_none() {
118 ImmediatePrevSibling::TraitDefName
122 ast::Impl(it) => if it.assoc_item_list().is_none()
123 && (it.for_token().is_none() || it.self_ty().is_some()) {
124 ImmediatePrevSibling::ImplDefType
128 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
135 pub(crate) fn determine_location(
136 sema: &Semantics<RootDatabase>,
137 original_file: &SyntaxNode,
139 name_like: &ast::NameLike,
140 ) -> Option<ImmediateLocation> {
141 let node = match name_like {
142 ast::NameLike::NameRef(name_ref) => {
143 if ast::RecordExprField::for_field_name(name_ref).is_some() {
145 .find_node_at_offset_with_macros(original_file, offset)
146 .map(ImmediateLocation::RecordExpr);
148 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
150 .find_node_at_offset_with_macros(original_file, offset)
151 .map(ImmediateLocation::RecordPat);
153 maximize_name_ref(name_ref)
155 ast::NameLike::Name(name) => {
156 if ast::RecordPatField::for_field_name(name).is_some() {
158 .find_node_at_offset_with_macros(original_file, offset)
159 .map(ImmediateLocation::RecordPat);
161 name.syntax().clone()
163 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
168 ast::TypeBoundList(_it) => return Some(ImmediateLocation::TypeBound),
173 let parent = match node.parent() {
174 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
175 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
176 // This is usually fine as the node expansion code above already accounts for that with
177 // the ancestors call, but there is one exception to this which is that when an attribute
178 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
179 // FIXME path expr and statement have a similar problem
181 if call.excl_token().is_none()
182 && call.token_tree().is_none()
183 && call.semicolon_token().is_none() =>
185 call.syntax().parent()?
191 return match node.kind() {
192 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
198 let res = match_ast! {
200 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
201 ast::Use(_it) => ImmediateLocation::Use,
202 ast::UseTree(_it) => ImmediateLocation::UseTree,
203 ast::UseTreeList(_it) => ImmediateLocation::UseTree,
204 ast::BlockExpr(_it) => ImmediateLocation::BlockExpr,
205 ast::SourceFile(_it) => ImmediateLocation::ItemList,
206 ast::ItemList(_it) => ImmediateLocation::ItemList,
207 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
208 ast::RecordField(it) => if it.ty().map_or(false, |it| it.syntax().text_range().contains(offset)) {
211 ImmediateLocation::RecordField
213 ast::RecordExprFieldList(_it) => sema
214 .find_node_at_offset_with_macros(original_file, offset)
215 .map(ImmediateLocation::RecordExprUpdate)?,
216 ast::TupleField(_it) => ImmediateLocation::TupleField,
217 ast::TupleFieldList(_it) => ImmediateLocation::TupleField,
218 ast::TypeBound(_it) => ImmediateLocation::TypeBound,
219 ast::TypeBoundList(_it) => ImmediateLocation::TypeBound,
220 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
221 Some(IMPL) => ImmediateLocation::Impl,
222 Some(TRAIT) => ImmediateLocation::Trait,
225 ast::GenericArgList(_it) => sema
226 .find_node_at_offset_with_macros(original_file, offset)
227 .map(ImmediateLocation::GenericArgList)?,
229 if it.item_list().is_none() {
230 ImmediateLocation::ModDeclaration(it)
235 ast::Attr(it) => ImmediateLocation::Attribute(it),
236 ast::FieldExpr(it) => {
239 .map(|e| e.syntax().text_range())
240 .and_then(|r| find_node_with_range(original_file, r));
241 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
243 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
249 ImmediateLocation::FieldAccess {
251 receiver_is_ambiguous_float_literal,
254 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
257 .map(|e| e.syntax().text_range())
258 .and_then(|r| find_node_with_range(original_file, r)),
259 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
261 ast::Visibility(it) => it.pub_token()
262 .and_then(|t| (t.text_range().end() < offset).then(|| ImmediateLocation::Visibility(it)))?,
269 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
270 // Maximize a nameref to its enclosing path if its the last segment of said path
271 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
272 let p = segment.parent_path();
273 if p.parent_path().is_none() {
277 .take_while(|it| it.text_range() == p.syntax().text_range())
284 name_ref.syntax().clone()
287 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
288 syntax.covering_element(range).ancestors().find_map(N::cast)
291 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
292 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
293 // where we only check the first parent with different text range.
296 .find(|it| it.kind() == IMPL)
297 .map(|it| ast::Impl::cast(it).unwrap())
298 .map(|it| it.trait_().is_some())
302 fn test_inside_impl_trait_block() {
303 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
304 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
305 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
306 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
309 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
310 element.into_token().and_then(previous_non_trivia_token)
313 /// Check if the token previous to the previous one is `for`.
314 /// For example, `for _ i$0` => true.
315 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
318 .and_then(previous_non_trivia_token)
319 .and_then(previous_non_trivia_token)
320 .filter(|it| it.kind() == T![for])
324 fn test_for_is_prev2() {
325 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
328 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
330 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
332 let loop_body = match_ast! {
334 ast::ForExpr(it) => it.loop_body(),
335 ast::WhileExpr(it) => it.loop_body(),
336 ast::LoopExpr(it) => it.loop_body(),
340 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
345 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
346 let mut token = token.prev_token();
347 while let Some(inner) = token.clone() {
348 if !inner.kind().is_trivia() {
351 token = inner.prev_token();
359 use syntax::algo::find_node_at_offset;
361 use crate::tests::position;
365 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
366 let (db, pos) = position(code);
368 let sema = Semantics::new(&db);
369 let original_file = sema.parse(pos.file_id);
371 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
373 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
378 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
379 check_pattern_is_applicable(code, |e| {
380 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
381 assert_eq!(determine_prev_sibling(name), sibling.into());
387 fn test_trait_loc() {
388 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
389 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
390 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
391 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
392 check_location(r"trait A$0 {}", None);
393 check_location(r"trait A { fn f$0 }", None);
398 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
399 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
400 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
401 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
402 check_location(r"impl A$0 {}", None);
403 check_location(r"impl A { fn f$0 }", None);
408 check_location(r"use f$0", ImmediateLocation::Use);
409 check_location(r"use f$0;", ImmediateLocation::Use);
410 check_location(r"use f::{f$0}", ImmediateLocation::UseTree);
411 check_location(r"use {f$0}", ImmediateLocation::UseTree);
415 fn test_record_field_loc() {
416 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
417 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
418 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
422 fn test_block_expr_loc() {
423 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
424 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::BlockExpr);
428 fn test_ident_pat_loc() {
429 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
430 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
431 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
432 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
436 fn test_ref_expr_loc() {
437 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
441 fn test_item_list_loc() {
442 check_location(r"i$0", ImmediateLocation::ItemList);
443 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
444 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
445 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
446 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
447 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
448 check_location(r"mod foo$0 {}", None);
452 fn test_impl_prev_sibling() {
453 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
454 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
455 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
456 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
457 check_prev_sibling(r"impl A for w$0 {}", None);
458 check_prev_sibling(r"impl A for w$0", None);
462 fn test_trait_prev_sibling() {
463 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
464 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
468 fn test_if_expr_prev_sibling() {
469 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
470 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
474 fn test_vis_prev_sibling() {
475 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
479 fn test_attr_prev_sibling() {
480 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);