Unnamed repository; edit this file 'description' to name the repository.
Merge #10204
10204: feat: Show the type of what is being dereferenced in a deref expression. r=theo-lw a=theo-lw
Addresses issue #10106.
In-progress - I'm trying to figure out why `hover_deref_expr_with_coercion` is failing.
Co-authored-by: Teddy_Wang <[email protected]>
| -rw-r--r-- | crates/ide/src/hover.rs | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs index 68b75f3ffc..14c0abaaf0 100644 --- a/crates/ide/src/hover.rs +++ b/crates/ide/src/hover.rs @@ -243,6 +243,11 @@ fn hover_ranged( })?; let res = match &expr_or_pat { Either::Left(ast::Expr::TryExpr(try_expr)) => hover_try_expr(sema, config, try_expr), + Either::Left(ast::Expr::PrefixExpr(prefix_expr)) + if prefix_expr.op_kind() == Some(ast::UnaryOp::Deref) => + { + hover_deref_expr(sema, config, prefix_expr) + } _ => None, }; let res = res.or_else(|| hover_type_info(sema, config, &expr_or_pat)); @@ -346,6 +351,70 @@ fn hover_try_expr( Some(res) } +fn hover_deref_expr( + sema: &Semantics<RootDatabase>, + config: &HoverConfig, + deref_expr: &ast::PrefixExpr, +) -> Option<HoverResult> { + let inner_ty = sema.type_of_expr(&deref_expr.expr()?)?.original; + let TypeInfo { original, adjusted } = + sema.type_of_expr(&ast::Expr::from(deref_expr.clone()))?; + + let mut res = HoverResult::default(); + let mut targets: Vec<hir::ModuleDef> = Vec::new(); + let mut push_new_def = |item: hir::ModuleDef| { + if !targets.contains(&item) { + targets.push(item); + } + }; + walk_and_push_ty(sema.db, &inner_ty, &mut push_new_def); + walk_and_push_ty(sema.db, &original, &mut push_new_def); + + res.markup = if let Some(adjusted_ty) = adjusted { + walk_and_push_ty(sema.db, &adjusted_ty, &mut push_new_def); + let original = original.display(sema.db).to_string(); + let adjusted = adjusted_ty.display(sema.db).to_string(); + let inner = inner_ty.display(sema.db).to_string(); + let type_len = "To type: ".len(); + let coerced_len = "Coerced to: ".len(); + let deref_len = "Dereferenced from: ".len(); + let max_len = (original.len() + type_len) + .max(adjusted.len() + coerced_len) + .max(inner.len() + deref_len); + format!( + "{bt_start}Dereferenced from: {:>ipad$}\nTo type: {:>apad$}\nCoerced to: {:>opad$}\n{bt_end}", + inner, + original, + adjusted, + ipad = max_len - deref_len, + apad = max_len - type_len, + opad = max_len - coerced_len, + bt_start = if config.markdown() { "```text\n" } else { "" }, + bt_end = if config.markdown() { "```\n" } else { "" } + ) + .into() + } else { + let original = original.display(sema.db).to_string(); + let inner = inner_ty.display(sema.db).to_string(); + let type_len = "To type: ".len(); + let deref_len = "Dereferenced from: ".len(); + let max_len = (original.len() + type_len).max(inner.len() + deref_len); + format!( + "{bt_start}Dereferenced from: {:>ipad$}\nTo type: {:>apad$}\n{bt_end}", + inner, + original, + ipad = max_len - deref_len, + apad = max_len - type_len, + bt_start = if config.markdown() { "```text\n" } else { "" }, + bt_end = if config.markdown() { "```\n" } else { "" } + ) + .into() + }; + res.actions.push(HoverAction::goto_type_from_targets(sema.db, targets)); + + Some(res) +} + fn hover_type_info( sema: &Semantics<RootDatabase>, config: &HoverConfig, @@ -4647,4 +4716,71 @@ fn foo() -> Option<()> { ```"#]], ); } + + #[test] + fn hover_deref_expr() { + check_hover_range( + r#" +//- minicore: deref +use core::ops::Deref; + +struct DerefExample<T> { + value: T +} + +impl<T> Deref for DerefExample<T> { + type Target = T; + + fn deref(&self) -> &Self::Target { + &self.value + } +} + +fn foo() { + let x = DerefExample { value: 0 }; + let y: i32 = $0*x$0; +} +"#, + expect![[r#" + ```text + Dereferenced from: DerefExample<i32> + To type: i32 + ``` + "#]], + ); + } + + #[test] + fn hover_deref_expr_with_coercion() { + check_hover_range( + r#" +//- minicore: deref +use core::ops::Deref; + +struct DerefExample<T> { + value: T +} + +impl<T> Deref for DerefExample<T> { + type Target = T; + + fn deref(&self) -> &Self::Target { + &self.value + } +} + +fn foo() { + let x = DerefExample { value: &&&&&0 }; + let y: &i32 = $0*x$0; +} +"#, + expect![[r#" + ```text + Dereferenced from: DerefExample<&&&&&i32> + To type: &&&&&i32 + Coerced to: &i32 + ``` + "#]], + ); + } } |