Merge #330

330: WIP: introduce hir::Name r=matklad a=matklad

Currently we are using `SmolStr` throughout the hir as a name, but that is really suboptimal choice: we'll probably want some kind of interning in the future, and we'll definitely need to add hygene info to names. This PR aims to replace strings with a slightly more abstract `Name` type. 

Co-authored-by: Aleksey Kladov <[email protected]>

1 files changed, 97 insertions, 0 deletions

diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
new file mode 100644
index 000000000..e4fc141a6
--- /dev/null
+++ b/crates/ra_hir/src/name.rs
@@ -0,0 +1,97 @@
+use std::fmt;
+
+use ra_syntax::{ast, SmolStr};
+
+/// `Name` is a wrapper around string, which is used in hir for both references
+/// and declarations. In theory, names should also carry hygene info, but we are
+/// not there yet!
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub struct Name {
+    text: SmolStr,
+}
+
+impl fmt::Display for Name {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Display::fmt(&self.text, f)
+    }
+}
+
+impl fmt::Debug for Name {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(&self.text, f)
+    }
+}
+
+impl Name {
+    pub(crate) fn as_known_name(&self) -> Option<KnownName> {
+        let name = match self.text.as_str() {
+            "isize" => KnownName::Isize,
+            "i8" => KnownName::I8,
+            "i16" => KnownName::I16,
+            "i32" => KnownName::I32,
+            "i64" => KnownName::I64,
+            "i128" => KnownName::I128,
+            "usize" => KnownName::Usize,
+            "u8" => KnownName::U8,
+            "u16" => KnownName::U16,
+            "u32" => KnownName::U32,
+            "u64" => KnownName::U64,
+            "u128" => KnownName::U128,
+            "f32" => KnownName::F32,
+            "f64" => KnownName::F64,
+            _ => return None,
+        };
+        Some(name)
+    }
+
+    fn new(text: SmolStr) -> Name {
+        Name { text }
+    }
+}
+
+pub(crate) trait AsName {
+    fn as_name(&self) -> Name;
+}
+
+impl AsName for ast::NameRef<'_> {
+    fn as_name(&self) -> Name {
+        Name::new(self.text())
+    }
+}
+
+impl AsName for ast::Name<'_> {
+    fn as_name(&self) -> Name {
+        Name::new(self.text())
+    }
+}
+
+impl AsName for ra_db::Dependency {
+    fn as_name(&self) -> Name {
+        Name::new(self.name.clone())
+    }
+}
+
+// Ideally, should be replaced with
+// ```
+// const ISIZE: Name = Name::new("isize")
+// ```
+// but const-fn is not that powerful yet.
+#[derive(Debug)]
+pub(crate) enum KnownName {
+    Isize,
+    I8,
+    I16,
+    I32,
+    I64,
+    I128,
+
+    Usize,
+    U8,
+    U16,
+    U32,
+    U64,
+    U128,
+
+    F32,
+    F64,
+}