Remove prev-sibling completion machinery

Author: Veykril

crates/ide-completion/src/completions/expr.rs

@@ -15,12 +15,12 @@ pub(crate) fn complete_expr_path(acc: &mut Completions, ctx: &CompletionContext)
         return;
     }
 
-    let (is_absolute_path, qualifier, in_block_expr, in_loop_body, is_func_update) =
+    let (is_absolute_path, qualifier, in_block_expr, in_loop_body, is_func_update, after_if_expr) =
         match ctx.nameref_ctx() {
             Some(NameRefContext {
                 path_ctx:
                     Some(PathCompletionCtx {
-                        kind: PathKind::Expr { in_block_expr, in_loop_body },
+                        kind: PathKind::Expr { in_block_expr, in_loop_body, after_if_expr },
                         is_absolute_path,
                         qualifier,
                         ..
@@ -33,6 +33,7 @@ pub(crate) fn complete_expr_path(acc: &mut Completions, ctx: &CompletionContext)
                 *in_block_expr,
                 *in_loop_body,
                 record_expr.as_ref().map_or(false, |&(_, it)| it),
+                *after_if_expr,
             ),
             _ => return,
         };
@@ -202,7 +203,7 @@ pub(crate) fn complete_expr_path(acc: &mut Completions, ctx: &CompletionContext)
                     add_keyword("let", "let");
                 }
 
-                if ctx.after_if() {
+                if after_if_expr {
                     add_keyword("else", "else {\n    $0\n}");
                     add_keyword("else if", "else if $1 {\n    $0\n}");
                 }

crates/ide-completion/src/context.rs

@@ -15,16 +15,16 @@ use ide_db::{
 use syntax::{
     algo::{find_node_at_offset, non_trivia_sibling},
     ast::{self, AttrKind, HasArgList, HasName, NameOrNameRef},
-    match_ast, AstNode, AstToken, NodeOrToken,
+    match_ast, AstNode, AstToken, Direction, NodeOrToken,
     SyntaxKind::{self, *},
     SyntaxNode, SyntaxToken, TextRange, TextSize, T,
 };
 use text_edit::Indel;
 
 use crate::{
     patterns::{
-        determine_location, determine_prev_sibling, is_in_loop_body, is_in_token_of_for_loop,
-        previous_token, ImmediateLocation, ImmediatePrevSibling,
+        determine_location, is_in_loop_body, is_in_token_of_for_loop, previous_token,
+        ImmediateLocation,
     },
     CompletionConfig,
 };
@@ -48,6 +48,7 @@ pub(super) enum PathKind {
     Expr {
         in_block_expr: bool,
         in_loop_body: bool,
+        after_if_expr: bool,
     },
     Type {
         in_tuple_struct: bool,
@@ -264,7 +265,6 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) incomplete_let: bool,
 
     pub(super) completion_location: Option<ImmediateLocation>,
-    pub(super) prev_sibling: Option<ImmediatePrevSibling>,
     pub(super) previous_token: Option<SyntaxToken>,
 
     pub(super) ident_ctx: IdentContext,
@@ -345,10 +345,6 @@ impl<'a> CompletionContext<'a> {
         matches!(self.completion_location, Some(ImmediateLocation::RefExpr))
     }
 
-    pub(crate) fn after_if(&self) -> bool {
-        matches!(self.prev_sibling, Some(ImmediatePrevSibling::IfExpr))
-    }
-
     // FIXME: This shouldn't exist
     pub(crate) fn is_path_disallowed(&self) -> bool {
         !self.qualifier_ctx.none()
@@ -527,7 +523,6 @@ impl<'a> CompletionContext<'a> {
             impl_def: None,
             incomplete_let: false,
             completion_location: None,
-            prev_sibling: None,
             previous_token: None,
             // dummy value, will be overwritten
             ident_ctx: IdentContext::UnexpandedAttrTT { fake_attribute_under_caret: None },
@@ -922,7 +917,6 @@ impl<'a> CompletionContext<'a> {
         };
         self.completion_location =
             determine_location(&self.sema, original_file, offset, &name_like);
-        self.prev_sibling = determine_prev_sibling(&name_like);
         self.impl_def = self
             .sema
             .token_ancestors_with_macros(self.token.clone())
@@ -1169,6 +1163,13 @@ impl<'a> CompletionContext<'a> {
                     find_node_in_file_compensated(original_file, &record_expr).zip(Some(true));
             }
         };
+        let after_if_expr = |node: SyntaxNode| {
+            let prev_expr = (|| {
+                let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
+                ast::ExprStmt::cast(prev_sibling)?.expr()
+            })();
+            matches!(prev_expr, Some(ast::Expr::IfExpr(_)))
+        };
 
         // We do not want to generate path completions when we are sandwiched between an item decl signature and its body.
         // ex. trait Foo $0 {}
@@ -1226,7 +1227,9 @@ impl<'a> CompletionContext<'a> {
                         path_ctx.has_call_parens = it.syntax().parent().map_or(false, |it| ast::CallExpr::can_cast(it.kind()));
                         let in_block_expr = is_in_block(it.syntax());
                         let in_loop_body = is_in_loop_body(it.syntax());
-                        Some(PathKind::Expr { in_block_expr, in_loop_body })
+                        let after_if_expr = after_if_expr(it.syntax().clone());
+
+                        Some(PathKind::Expr { in_block_expr, in_loop_body, after_if_expr })
                     },
                     ast::TupleStructPat(it) => {
                         path_ctx.has_call_parens = true;
@@ -1274,8 +1277,9 @@ impl<'a> CompletionContext<'a> {
                                return Some(parent.and_then(ast::MacroExpr::cast).map(|it| {
                                     let in_loop_body = is_in_loop_body(it.syntax());
                                     let in_block_expr = is_in_block(it.syntax());
+                                    let after_if_expr = after_if_expr(it.syntax().clone());
                                     fill_record_expr(it.syntax());
-                                    PathKind::Expr { in_block_expr, in_loop_body }
+                                    PathKind::Expr { in_block_expr, in_loop_body, after_if_expr }
                                 }));
                             },
                         }

crates/ide-completion/src/patterns.rs

@@ -7,22 +7,15 @@
 use hir::Semantics;
 use ide_db::RootDatabase;
 use syntax::{
-    algo::non_trivia_sibling,
     ast::{self, HasLoopBody, HasName},
-    match_ast, AstNode, Direction, SyntaxElement,
+    match_ast, AstNode, SyntaxElement,
     SyntaxKind::*,
     SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
 
 #[cfg(test)]
 use crate::tests::check_pattern_is_applicable;
 
-/// Immediate previous node to what we are completing.
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
-pub(crate) enum ImmediatePrevSibling {
-    IfExpr,
-}
-
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum TypeAnnotation {
     Let(Option<ast::Pat>),
@@ -46,45 +39,6 @@ pub(crate) enum ImmediateLocation {
     GenericArgList(ast::GenericArgList),
 }
 
-pub(crate) fn determine_prev_sibling(name_like: &ast::NameLike) -> Option<ImmediatePrevSibling> {
-    let node = match name_like {
-        ast::NameLike::NameRef(name_ref) => maximize_name_ref(name_ref),
-        ast::NameLike::Name(n) => n.syntax().clone(),
-        ast::NameLike::Lifetime(lt) => lt.syntax().clone(),
-    };
-    let node = match node.parent().and_then(ast::MacroCall::cast) {
-        // When a path is being typed after the name of a trait/type of an impl it is being
-        // parsed as a macro, so when the trait/impl has a block following it an we are between the
-        // name and block the macro will attach the block to itself so maximizing fails to take
-        // that into account
-        // FIXME path expr and statement have a similar problem with attrs
-        Some(call)
-            if call.excl_token().is_none()
-                && call.token_tree().map_or(false, |t| t.l_curly_token().is_some())
-                && call.semicolon_token().is_none() =>
-        {
-            call.syntax().clone()
-        }
-        _ => node,
-    };
-    let prev_sibling = non_trivia_sibling(node.into(), Direction::Prev)?.into_node()?;
-    let res = match_ast! {
-        match prev_sibling {
-            ast::ExprStmt(it) => {
-                let node = it.expr().filter(|_| it.semicolon_token().is_none())?.syntax().clone();
-                match_ast! {
-                    match node {
-                        ast::IfExpr(_) => ImmediatePrevSibling::IfExpr,
-                        _ => return None,
-                    }
-                }
-            },
-            _ => return None,
-        }
-    };
-    Some(res)
-}
-
 pub(crate) fn determine_location(
     sema: &Semantics<RootDatabase>,
     original_file: &SyntaxNode,
@@ -316,22 +270,8 @@ mod tests {
         );
     }
 
-    fn check_prev_sibling(code: &str, sibling: impl Into<Option<ImmediatePrevSibling>>) {
-        check_pattern_is_applicable(code, |e| {
-            let name = &e.parent().and_then(ast::NameLike::cast).expect("Expected a namelike");
-            assert_eq!(determine_prev_sibling(name), sibling.into());
-            true
-        });
-    }
-
     #[test]
     fn test_ref_expr_loc() {
         check_location(r"fn my_fn() { let x = &m$0 foo; }", ImmediateLocation::RefExpr);
     }
-
-    #[test]
-    fn test_if_expr_prev_sibling() {
-        check_prev_sibling(r"fn foo() { if true {} w$0", ImmediatePrevSibling::IfExpr);
-        check_prev_sibling(r"fn foo() { if true {}; w$0", None);
-    }
 }