1 files changed, 114 insertions, 0 deletions

diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
new file mode 100644
index 000000000..22bd469f0
--- /dev/null
+++ b/crates/ra_hir_def/src/adt.rs
@@ -0,0 +1,114 @@
+//! Defines hir-level representation of structs, enums and unions
+
+use std::sync::Arc;
+
+use hir_expand::name::{AsName, Name};
+use ra_arena::Arena;
+use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
+
+use crate::{
+    db::DefDatabase2, type_ref::TypeRef, AstItemDef, EnumId, LocalEnumVariantId,
+    LocalStructFieldId, StructId,
+};
+
+/// Note that we use `StructData` for unions as well!
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StructData {
+    pub name: Option<Name>,
+    pub variant_data: Arc<VariantData>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct EnumData {
+    pub name: Option<Name>,
+    pub variants: Arena<LocalEnumVariantId, EnumVariantData>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct EnumVariantData {
+    pub name: Option<Name>,
+    pub variant_data: Arc<VariantData>,
+}
+
+/// Fields of an enum variant or struct
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct VariantData(VariantDataInner);
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+enum VariantDataInner {
+    Struct(Arena<LocalStructFieldId, StructFieldData>),
+    Tuple(Arena<LocalStructFieldId, StructFieldData>),
+    Unit,
+}
+
+/// A single field of an enum variant or struct
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StructFieldData {
+    pub name: Name,
+    pub type_ref: TypeRef,
+}
+
+impl StructData {
+    pub(crate) fn struct_data_query(db: &impl DefDatabase2, struct_: StructId) -> Arc<StructData> {
+        let src = struct_.source(db);
+        let name = src.ast.name().map(|n| n.as_name());
+        let variant_data = VariantData::new(src.ast.kind());
+        let variant_data = Arc::new(variant_data);
+        Arc::new(StructData { name, variant_data })
+    }
+}
+
+impl EnumData {
+    pub(crate) fn enum_data_query(db: &impl DefDatabase2, e: EnumId) -> Arc<EnumData> {
+        let src = e.source(db);
+        let name = src.ast.name().map(|n| n.as_name());
+        let variants = src
+            .ast
+            .variant_list()
+            .into_iter()
+            .flat_map(|it| it.variants())
+            .map(|var| EnumVariantData {
+                name: var.name().map(|it| it.as_name()),
+                variant_data: Arc::new(VariantData::new(var.kind())),
+            })
+            .collect();
+        Arc::new(EnumData { name, variants })
+    }
+}
+
+impl VariantData {
+    fn new(flavor: ast::StructKind) -> Self {
+        let inner = match flavor {
+            ast::StructKind::Tuple(fl) => {
+                let fields = fl
+                    .fields()
+                    .enumerate()
+                    .map(|(i, fd)| StructFieldData {
+                        name: Name::new_tuple_field(i),
+                        type_ref: TypeRef::from_ast_opt(fd.type_ref()),
+                    })
+                    .collect();
+                VariantDataInner::Tuple(fields)
+            }
+            ast::StructKind::Named(fl) => {
+                let fields = fl
+                    .fields()
+                    .map(|fd| StructFieldData {
+                        name: fd.name().map(|n| n.as_name()).unwrap_or_else(Name::missing),
+                        type_ref: TypeRef::from_ast_opt(fd.ascribed_type()),
+                    })
+                    .collect();
+                VariantDataInner::Struct(fields)
+            }
+            ast::StructKind::Unit => VariantDataInner::Unit,
+        };
+        VariantData(inner)
+    }
+
+    pub fn fields(&self) -> Option<&Arena<LocalStructFieldId, StructFieldData>> {
+        match &self.0 {
+            VariantDataInner::Struct(fields) | VariantDataInner::Tuple(fields) => Some(fields),
+            _ => None,
+        }
+    }
+}