1 files changed, 142 insertions, 0 deletions

diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
new file mode 100644
index 000000000..720896ee8
--- /dev/null
+++ b/crates/ra_hir_expand/src/name.rs
@@ -0,0 +1,142 @@
+//! FIXME: write short doc here
+
+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 hygiene info, but we are
+/// not there yet!
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct Name(Repr);
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+enum Repr {
+    Text(SmolStr),
+    TupleField(usize),
+}
+
+impl fmt::Display for Name {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match &self.0 {
+            Repr::Text(text) => fmt::Display::fmt(&text, f),
+            Repr::TupleField(idx) => fmt::Display::fmt(&idx, f),
+        }
+    }
+}
+
+impl Name {
+    /// Note: this is private to make creating name from random string hard.
+    /// Hopefully, this should allow us to integrate hygiene cleaner in the
+    /// future, and to switch to interned representation of names.
+    const fn new_text(text: SmolStr) -> Name {
+        Name(Repr::Text(text))
+    }
+
+    pub fn new_tuple_field(idx: usize) -> Name {
+        Name(Repr::TupleField(idx))
+    }
+
+    /// Shortcut to create inline plain text name
+    const fn new_inline_ascii(len: usize, text: &[u8]) -> Name {
+        Name::new_text(SmolStr::new_inline_from_ascii(len, text))
+    }
+
+    /// Resolve a name from the text of token.
+    fn resolve(raw_text: &SmolStr) -> Name {
+        let raw_start = "r#";
+        if raw_text.as_str().starts_with(raw_start) {
+            Name::new_text(SmolStr::new(&raw_text[raw_start.len()..]))
+        } else {
+            Name::new_text(raw_text.clone())
+        }
+    }
+
+    pub fn missing() -> Name {
+        Name::new_text("[missing name]".into())
+    }
+
+    pub fn as_tuple_index(&self) -> Option<usize> {
+        match self.0 {
+            Repr::TupleField(idx) => Some(idx),
+            _ => None,
+        }
+    }
+}
+
+pub trait AsName {
+    fn as_name(&self) -> Name;
+}
+
+impl AsName for ast::NameRef {
+    fn as_name(&self) -> Name {
+        match self.as_tuple_field() {
+            Some(idx) => Name::new_tuple_field(idx),
+            None => Name::resolve(self.text()),
+        }
+    }
+}
+
+impl AsName for ast::Name {
+    fn as_name(&self) -> Name {
+        Name::resolve(self.text())
+    }
+}
+
+impl AsName for ast::FieldKind {
+    fn as_name(&self) -> Name {
+        match self {
+            ast::FieldKind::Name(nr) => nr.as_name(),
+            ast::FieldKind::Index(idx) => Name::new_tuple_field(idx.text().parse().unwrap()),
+        }
+    }
+}
+
+impl AsName for ra_db::Dependency {
+    fn as_name(&self) -> Name {
+        Name::new_text(self.name.clone())
+    }
+}
+
+// Primitives
+pub const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
+pub const I8: Name = Name::new_inline_ascii(2, b"i8");
+pub const I16: Name = Name::new_inline_ascii(3, b"i16");
+pub const I32: Name = Name::new_inline_ascii(3, b"i32");
+pub const I64: Name = Name::new_inline_ascii(3, b"i64");
+pub const I128: Name = Name::new_inline_ascii(4, b"i128");
+pub const USIZE: Name = Name::new_inline_ascii(5, b"usize");
+pub const U8: Name = Name::new_inline_ascii(2, b"u8");
+pub const U16: Name = Name::new_inline_ascii(3, b"u16");
+pub const U32: Name = Name::new_inline_ascii(3, b"u32");
+pub const U64: Name = Name::new_inline_ascii(3, b"u64");
+pub const U128: Name = Name::new_inline_ascii(4, b"u128");
+pub const F32: Name = Name::new_inline_ascii(3, b"f32");
+pub const F64: Name = Name::new_inline_ascii(3, b"f64");
+pub const BOOL: Name = Name::new_inline_ascii(4, b"bool");
+pub const CHAR: Name = Name::new_inline_ascii(4, b"char");
+pub const STR: Name = Name::new_inline_ascii(3, b"str");
+
+// Special names
+pub const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
+pub const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
+pub const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
+
+// Components of known path (value or mod name)
+pub const STD: Name = Name::new_inline_ascii(3, b"std");
+pub const ITER: Name = Name::new_inline_ascii(4, b"iter");
+pub const OPS: Name = Name::new_inline_ascii(3, b"ops");
+pub const FUTURE: Name = Name::new_inline_ascii(6, b"future");
+pub const RESULT: Name = Name::new_inline_ascii(6, b"result");
+pub const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
+
+// Components of known path (type name)
+pub const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
+pub const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
+pub const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
+pub const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
+pub const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
+pub const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
+pub const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
+pub const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
+pub const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");