allow dyn diagnostics

crates/ra_hir/src/diagnostics.rs

@@ -1,6 +1,60 @@
-use crate::{expr::ExprId};
+use std::{fmt, any::Any};
 
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub enum FunctionDiagnostic {
-    NoSuchField { expr: ExprId, field: usize },
+use ra_syntax::{SyntaxNodePtr, AstPtr, ast};
+
+use crate::HirFileId;
+
+pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
+    fn file(&self) -> HirFileId;
+    fn syntax_node(&self) -> SyntaxNodePtr;
+    fn message(&self) -> String;
+    fn as_any(&self) -> &(Any + Send + 'static);
+}
+
+impl dyn Diagnostic {
+    pub fn downcast_ref<D: Diagnostic>(&self) -> Option<&D> {
+        self.as_any().downcast_ref()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct Diagnostics {
+    data: Vec<Box<dyn Diagnostic>>,
+}
+
+impl Diagnostics {
+    pub fn push(&mut self, d: impl Diagnostic) {
+        self.data.push(Box::new(d))
+    }
+
+    pub fn iter<'a>(&'a self) -> impl Iterator<Item = &'a dyn Diagnostic> + 'a {
+        self.data.iter().map(|it| it.as_ref())
+    }
+}
+
+#[derive(Debug)]
+pub struct NoSuchField {
+    pub(crate) file: HirFileId,
+    pub(crate) field: AstPtr<ast::NamedField>,
+}
+
+impl NoSuchField {
+    pub fn field(&self) -> AstPtr<ast::NamedField> {
+        self.field
+    }
+}
+
+impl Diagnostic for NoSuchField {
+    fn file(&self) -> HirFileId {
+        self.file
+    }
+    fn syntax_node(&self) -> SyntaxNodePtr {
+        self.field.into()
+    }
+    fn message(&self) -> String {
+        "no such field".to_string()
+    }
+    fn as_any(&self) -> &(Any + Send + 'static) {
+        self
+    }
 }