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 {
40 ModDeclaration(ast::Module),
41 // Original file ast node
43 receiver: Option<ast::Expr>,
46 // Original file ast node
48 receiver: Option<ast::Expr>,
49 receiver_is_ambiguous_float_literal: bool,
51 // Original file ast node
52 // Only set from a type arg
53 GenericArgList(ast::GenericArgList),
54 // Original file ast node
55 /// The record expr of the field name we are completing
56 RecordExpr(ast::RecordExpr),
57 // Original file ast node
58 /// The record pat of the field name we are completing
59 RecordPat(ast::RecordPat),
62 pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
63 let node = match name_like {
64 ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
65 ast::NameLike::Name(n) => n.syntax().clone(),
66 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
68 let node = match node.parent().and_then(ast::MacroCall::cast) {
69 // When a path is being typed after the name of a trait/type of an impl it is being
70 // parsed as a macro, so when the trait/impl has a block following it an we are between the
71 // name and block the macro will attach the block to itself so maximizing fails to take
73 // FIXME path expr and statement have a similar problem with attrs
75 if call.excl_token().is_none()
76 && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
77 && call.semicolon_token().is_none() =>
83 let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
84 if prev_sibling.kind() == ERROR {
85 let prev_sibling = prev_sibling.first_child()?;
86 let res = match_ast! {
88 // vis followed by random ident will always error the parser
89 ast::Visibility(_it) => ImmediatePrevSibling::Visibility,
95 let res = match_ast! {
97 ast::ExprStmt(it) => {
98 let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
101 ast::IfExpr(_it) => ImmediatePrevSibling::IfExpr,
106 ast::Trait(it) => if it.assoc_item_list().is_none() {
107 ImmediatePrevSibling::TraitDefName
111 ast::Impl(it) => if it.assoc_item_list().is_none()
112 && (it.for_token().is_none() || it.self_ty().is_some()) {
113 ImmediatePrevSibling::ImplDefType
117 ast::Attr(_it) => ImmediatePrevSibling::Attribute,
124 pub(crate) fn determine_location(
125 sema: &Semantics<RootDatabase>,
126 original_file: &SyntaxNode,
128 name_like: &ast::NameLike,
129 ) -> Option<ImmediateLocation> {
130 let node = match name_like {
131 ast::NameLike::NameRef(name_ref) => {
132 if ast::RecordExprField::for_field_name(name_ref).is_some() {
134 .find_node_at_offset_with_macros(original_file, offset)
135 .map(ImmediateLocation::RecordExpr);
137 if ast::RecordPatField::for_field_name_ref(name_ref).is_some() {
139 .find_node_at_offset_with_macros(original_file, offset)
140 .map(ImmediateLocation::RecordPat);
142 maximize_name_ref(name_ref)
144 ast::NameLike::Name(name) => {
145 if ast::RecordPatField::for_field_name(name).is_some() {
147 .find_node_at_offset_with_macros(original_file, offset)
148 .map(ImmediateLocation::RecordPat);
150 name.syntax().clone()
152 ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
155 let parent = match node.parent() {
156 Some(parent) => match ast::MacroCall::cast(parent.clone()) {
157 // When a path is being typed in an (Assoc)ItemList the parser will always emit a macro_call.
158 // This is usually fine as the node expansion code above already accounts for that with
159 // the ancestors call, but there is one exception to this which is that when an attribute
160 // precedes it the code above will not walk the Path to the parent MacroCall as their ranges differ.
161 // FIXME path expr and statement have a similar problem
163 if call.excl_token().is_none()
164 && call.token_tree().is_none()
165 && call.semicolon_token().is_none() =>
167 call.syntax().parent()?
173 return match node.kind() {
174 MACRO_ITEMS | SOURCE_FILE => Some(ImmediateLocation::ItemList),
179 let res = match_ast! {
181 ast::IdentPat(_it) => ImmediateLocation::IdentPat,
182 ast::Use(_it) => ImmediateLocation::Use,
183 ast::BlockExpr(_it) => ImmediateLocation::BlockExpr,
184 ast::SourceFile(_it) => ImmediateLocation::ItemList,
185 ast::ItemList(_it) => ImmediateLocation::ItemList,
186 ast::RefExpr(_it) => ImmediateLocation::RefExpr,
187 ast::RecordField(_it) => ImmediateLocation::RecordField,
188 ast::AssocItemList(it) => match it.syntax().parent().map(|it| it.kind()) {
189 Some(IMPL) => ImmediateLocation::Impl,
190 Some(TRAIT) => ImmediateLocation::Trait,
193 ast::GenericArgList(_it) => sema
194 .find_node_at_offset_with_macros(original_file, offset)
195 .map(ImmediateLocation::GenericArgList)?,
197 if it.item_list().is_none() {
198 ImmediateLocation::ModDeclaration(it)
203 ast::Attr(it) => ImmediateLocation::Attribute(it),
204 ast::FieldExpr(it) => {
207 .map(|e| e.syntax().text_range())
208 .and_then(|r| find_node_with_range(original_file, r));
209 let receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) = &receiver {
211 ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
217 ImmediateLocation::FieldAccess {
219 receiver_is_ambiguous_float_literal,
222 ast::MethodCallExpr(it) => ImmediateLocation::MethodCall {
225 .map(|e| e.syntax().text_range())
226 .and_then(|r| find_node_with_range(original_file, r)),
227 has_parens: it.arg_list().map_or(false, |it| it.l_paren_token().is_some())
235 fn maximize_name_ref(name_ref: &ast::NameRef) -> SyntaxNode {
236 // Maximize a nameref to its enclosing path if its the last segment of said path
237 if let Some(segment) = name_ref.syntax().parent().and_then(ast::PathSegment::cast) {
238 let p = segment.parent_path();
239 if p.parent_path().is_none() {
243 .take_while(|it| it.text_range() == p.syntax().text_range())
250 name_ref.syntax().clone()
253 fn find_node_with_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
254 syntax.covering_element(range).ancestors().find_map(N::cast)
257 pub(crate) fn inside_impl_trait_block(element: SyntaxElement) -> bool {
258 // Here we search `impl` keyword up through the all ancestors, unlike in `has_impl_parent`,
259 // where we only check the first parent with different text range.
262 .find(|it| it.kind() == IMPL)
263 .map(|it| ast::Impl::cast(it).unwrap())
264 .map(|it| it.trait_().is_some())
268 fn test_inside_impl_trait_block() {
269 check_pattern_is_applicable(r"impl Foo for Bar { f$0 }", inside_impl_trait_block);
270 check_pattern_is_applicable(r"impl Foo for Bar { fn f$0 }", inside_impl_trait_block);
271 check_pattern_is_not_applicable(r"impl A { f$0 }", inside_impl_trait_block);
272 check_pattern_is_not_applicable(r"impl A { fn f$0 }", inside_impl_trait_block);
275 pub(crate) fn previous_token(element: SyntaxElement) -> Option<SyntaxToken> {
276 element.into_token().and_then(previous_non_trivia_token)
279 /// Check if the token previous to the previous one is `for`.
280 /// For example, `for _ i$0` => true.
281 pub(crate) fn for_is_prev2(element: SyntaxElement) -> bool {
284 .and_then(previous_non_trivia_token)
285 .and_then(previous_non_trivia_token)
286 .filter(|it| it.kind() == T![for])
290 fn test_for_is_prev2() {
291 check_pattern_is_applicable(r"for i i$0", for_is_prev2);
294 pub(crate) fn is_in_loop_body(node: &SyntaxNode) -> bool {
296 .take_while(|it| it.kind() != FN && it.kind() != CLOSURE_EXPR)
298 let loop_body = match_ast! {
300 ast::ForExpr(it) => it.loop_body(),
301 ast::WhileExpr(it) => it.loop_body(),
302 ast::LoopExpr(it) => it.loop_body(),
306 loop_body.filter(|it| it.syntax().text_range().contains_range(node.text_range()))
311 fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
312 let mut token = token.prev_token();
313 while let Some(inner) = token.clone() {
314 if !inner.kind().is_trivia() {
317 token = inner.prev_token();
325 use syntax::algo::find_node_at_offset;
327 use crate::tests::position;
331 fn check_location(code: &str, loc: impl Into<Option<ImmediateLocation>>) {
332 let (db, pos) = position(code);
334 let sema = Semantics::new(&db);
335 let original_file = sema.parse(pos.file_id);
337 let name_like = find_node_at_offset(original_file.syntax(), pos.offset).unwrap();
339 determine_location(&sema, original_file.syntax(), pos.offset, &name_like),
344 fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
345 check_pattern_is_applicable(code, |e| {
346 let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
347 assert_eq!(determine_prev_sibling(name), sibling.into());
353 fn test_trait_loc() {
354 check_location(r"trait A { f$0 }", ImmediateLocation::Trait);
355 check_location(r"trait A { #[attr] f$0 }", ImmediateLocation::Trait);
356 check_location(r"trait A { f$0 fn f() {} }", ImmediateLocation::Trait);
357 check_location(r"trait A { fn f() {} f$0 }", ImmediateLocation::Trait);
358 check_location(r"trait A$0 {}", None);
359 check_location(r"trait A { fn f$0 }", None);
364 check_location(r"impl A { f$0 }", ImmediateLocation::Impl);
365 check_location(r"impl A { #[attr] f$0 }", ImmediateLocation::Impl);
366 check_location(r"impl A { f$0 fn f() {} }", ImmediateLocation::Impl);
367 check_location(r"impl A { fn f() {} f$0 }", ImmediateLocation::Impl);
368 check_location(r"impl A$0 {}", None);
369 check_location(r"impl A { fn f$0 }", None);
374 check_location(r"use f$0", ImmediateLocation::Use);
375 check_location(r"use f$0;", ImmediateLocation::Use);
376 check_location(r"use f::{f$0}", None);
377 check_location(r"use {f$0}", None);
381 fn test_record_field_loc() {
382 check_location(r"struct Foo { f$0 }", ImmediateLocation::RecordField);
383 check_location(r"struct Foo { f$0 pub f: i32}", ImmediateLocation::RecordField);
384 check_location(r"struct Foo { pub f: i32, f$0 }", ImmediateLocation::RecordField);
388 fn test_block_expr_loc() {
389 check_location(r"fn my_fn() { let a = 2; f$0 }", ImmediateLocation::BlockExpr);
390 check_location(r"fn my_fn() { f$0 f }", ImmediateLocation::BlockExpr);
394 fn test_ident_pat_loc() {
395 check_location(r"fn my_fn(m$0) {}", ImmediateLocation::IdentPat);
396 check_location(r"fn my_fn() { let m$0 }", ImmediateLocation::IdentPat);
397 check_location(r"fn my_fn(&m$0) {}", ImmediateLocation::IdentPat);
398 check_location(r"fn my_fn() { let &m$0 }", ImmediateLocation::IdentPat);
402 fn test_ref_expr_loc() {
403 check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
407 fn test_item_list_loc() {
408 check_location(r"i$0", ImmediateLocation::ItemList);
409 check_location(r"#[attr] i$0", ImmediateLocation::ItemList);
410 check_location(r"fn f() {} i$0", ImmediateLocation::ItemList);
411 check_location(r"mod foo { f$0 }", ImmediateLocation::ItemList);
412 check_location(r"mod foo { #[attr] f$0 }", ImmediateLocation::ItemList);
413 check_location(r"mod foo { fn f() {} f$0 }", ImmediateLocation::ItemList);
414 check_location(r"mod foo$0 {}", None);
418 fn test_impl_prev_sibling() {
419 check_prev_sibling(r"impl A w$0 ", ImmediatePrevSibling::ImplDefType);
420 check_prev_sibling(r"impl A w$0 {}", ImmediatePrevSibling::ImplDefType);
421 check_prev_sibling(r"impl A for A w$0 ", ImmediatePrevSibling::ImplDefType);
422 check_prev_sibling(r"impl A for A w$0 {}", ImmediatePrevSibling::ImplDefType);
423 check_prev_sibling(r"impl A for w$0 {}", None);
424 check_prev_sibling(r"impl A for w$0", None);
428 fn test_trait_prev_sibling() {
429 check_prev_sibling(r"trait A w$0 ", ImmediatePrevSibling::TraitDefName);
430 check_prev_sibling(r"trait A w$0 {}", ImmediatePrevSibling::TraitDefName);
434 fn test_if_expr_prev_sibling() {
435 check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
436 check_prev_sibling(r"fn foo() { if true {}; w$0", None);
440 fn test_vis_prev_sibling() {
441 check_prev_sibling(r"pub w$0", ImmediatePrevSibling::Visibility);
445 fn test_attr_prev_sibling() {
446 check_prev_sibling(r"#[attr] w$0", ImmediatePrevSibling::Attribute);