Show types in hover messages

crates/ide/src/ide/hover.rs

@@ -1,5 +1,5 @@
 use crate::def::{AstPtr, Expr, ResolveResult};
-use crate::{DefDatabase, FilePos, NameKind};
+use crate::{FilePos, NameKind, TyDatabase};
 use builtin::ALL_BUILTINS;
 use rowan::ast::AstNode;
 use rowan::TextRange;
@@ -12,10 +12,7 @@ pub struct HoverResult {
     pub markup: String,
 }
 
-pub(crate) fn hover(
-    db: &dyn DefDatabase,
-    FilePos { file_id, pos }: FilePos,
-) -> Option<HoverResult> {
+pub(crate) fn hover(db: &dyn TyDatabase, FilePos { file_id, pos }: FilePos) -> Option<HoverResult> {
     let parse = db.parse(file_id);
     let tok = best_token_at_offset(&parse.syntax_node(), pos)?;
     let ptr = tok.parent_ancestors().find_map(|node| {
@@ -34,6 +31,7 @@ pub(crate) fn hover(
     let module = db.module(file_id);
     let source_map = db.source_map(file_id);
     let nameres = db.name_resolution(file_id);
+    let infer = db.infer(file_id);
 
     let mut name = None;
 
@@ -42,6 +40,7 @@ pub(crate) fn hover(
             None => {}
             Some(ResolveResult::Builtin(name)) => {
                 let b = &ALL_BUILTINS[*name];
+                // TODO: Types of builtins.
                 let markup = format!(
                     "{}\n\n{}",
                     b.summary,
@@ -54,7 +53,8 @@ pub(crate) fn hover(
                     Expr::Reference(text) => text,
                     _ => return None,
                 };
-                let mut markup = format!("Attribute `{}` from:", text);
+                let ty = infer.display_ty(infer.ty_for_expr(expr)).to_string();
+                let mut markup = format!("`with` attribute `{text}`: `{ty}`");
                 for (&expr, i) in withs.iter().zip(1..) {
                     let ptr = source_map.node_for_expr(expr)?;
                     let with_node = ast::With::cast(ptr.to_node(&parse.syntax_node()))?;
@@ -72,6 +72,7 @@ pub(crate) fn hover(
     }
 
     if let Some(name) = name.or_else(|| source_map.name_for_node(ptr.clone())) {
+        let ty = infer.display_ty(infer.ty_for_name(name)).to_string();
         let text = &module[name].text;
         let kind = match module[name].kind {
             NameKind::LetIn => "Let binding",
@@ -82,7 +83,7 @@ pub(crate) fn hover(
         };
         return Some(HoverResult {
             range,
-            markup: format!("{kind} `{text}`"),
+            markup: format!("{kind} `{text}`: `{ty}`"),
         });
     }
 
@@ -111,33 +112,37 @@ mod tests {
 
     #[test]
     fn definition() {
-        check("let $0a = 1; in a", "a", expect!["Let binding `a`"]);
-        check("let a.$0a = 1; in a", "a", expect!["Attrset attribute `a`"]);
-        check("{ $0a = 1; }", "a", expect!["Attrset attribute `a`"]);
+        check("let $0a = 1; in a", "a", expect!["Let binding `a`: `int`"]);
+        check(
+            "let a.$0a = 1; in a",
+            "a",
+            expect!["Attrset attribute `a`: `int`"],
+        );
+        check("{ $0a = 1; }", "a", expect!["Attrset attribute `a`: `int`"]);
         check(
             "rec { $0a = 1; }",
             "a",
-            expect!["Rec-attrset attribute `a`"],
+            expect!["Rec-attrset attribute `a`: `int`"],
         );
-        check("$0a: a", "a", expect!["Parameter `a`"]);
-        check("{$0a}: a", "a", expect!["Field parameter `a`"]);
+        check("$0a: a", "a", expect!["Parameter `a`: `?`"]);
+        check("{$0a}: a", "a", expect!["Field parameter `a`: `?`"]);
     }
 
     #[test]
     fn reference() {
-        check("let a = 1; in $0a", "a", expect!["Let binding `a`"]);
+        check("let a = 1; in $0a", "a", expect!["Let binding `a`: `int`"]);
         check(
             "let a = 1; in { inherit $0a; }",
             "a",
-            expect!["Let binding `a`"],
+            expect!["Let binding `a`: `int`"],
         );
         check(
             "let a = 1; in rec { inherit $0a; }",
             "a",
-            expect!["Let binding `a`"],
+            expect!["Let binding `a`: `int`"],
         );
-        check("a: $0a", "a", expect!["Parameter `a`"]);
-        check("{a}: $0a", "a", expect!["Field parameter `a`"]);
+        check("a: $0a", "a", expect!["Parameter `a`: `?`"]);
+        check("{a}: $0a", "a", expect!["Field parameter `a`: `?`"]);
     }
 
     #[test]
@@ -146,7 +151,7 @@ mod tests {
             "with 1; $0a",
             "a",
             expect![[r#"
-                Attribute `a` from:
+                `with` attribute `a`: `?`
                 1. `with 1;`
             "#]],
         );
@@ -154,7 +159,7 @@ mod tests {
             "with 1; with 2; $0a",
             "a",
             expect![[r#"
-                Attribute `a` from:
+                `with` attribute `a`: `?`
                 1. `with 2;`
                 2. `with 1;`
             "#]],

crates/ide/src/ide/mod.rs

@@ -10,6 +10,7 @@ mod syntax_highlighting;
 
 use crate::base::SourceDatabaseStorage;
 use crate::def::DefDatabaseStorage;
+use crate::ty::TyDatabaseStorage;
 use crate::{Change, Diagnostic, FileId, FilePos, FileRange, WorkspaceEdit};
 use rowan::TextRange;
 use salsa::{Database, Durability, ParallelDatabase};
@@ -34,7 +35,7 @@ pub use salsa::Cancelled;
 
 pub type Cancellable<T> = Result<T, Cancelled>;
 
-#[salsa::database(SourceDatabaseStorage, DefDatabaseStorage)]
+#[salsa::database(SourceDatabaseStorage, DefDatabaseStorage, TyDatabaseStorage)]
 #[derive(Default)]
 pub struct RootDatabase {
     storage: salsa::Storage<Self>,