introduce known names

4 files changed, 71 insertions, 29 deletions

diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index bf43cd0ae..5bbb09c01 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -38,7 +38,7 @@ use ra_db::{LocationIntener, SourceRootId, FileId, Cancelable};
 use crate::{
     db::HirDatabase,
     arena::{Arena, Id},
-    name::AsName,
+    name::{AsName, KnownName},
 };
 
 pub use self::{
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 7f42c9f04..cdad31be7 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -17,9 +17,25 @@ impl fmt::Display for Name {
 }
 
 impl Name {
-    // TODO: get rid of this?
-    pub(crate) fn as_str(&self) -> &str {
-        self.text.as_str()
+    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)
     }
 
     #[cfg(not(test))]
@@ -54,3 +70,28 @@ impl AsName for ra_db::Dependency {
         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,
+}
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index dc3323b1a..ad097d1f1 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -95,7 +95,7 @@ pub enum Ty {
     Tuple(Vec<Ty>),
 
     // The projection of an associated type.  For example,
-    // `<T as Trait<..>>::N`.
+    // `<T as Trait<..>>::N`.pub
     // Projection(ProjectionTy),
 
     // Opaque (`impl Trait`) type found in a return type.
@@ -180,12 +180,11 @@ impl Ty {
         path: &Path,
     ) -> Cancelable<Self> {
         if let Some(name) = path.as_ident() {
-            let name = name.as_str(); // :-(
-            if let Some(int_ty) = primitive::IntTy::from_string(name) {
+            if let Some(int_ty) = primitive::IntTy::from_name(name) {
                 return Ok(Ty::Int(int_ty));
-            } else if let Some(uint_ty) = primitive::UintTy::from_string(name) {
+            } else if let Some(uint_ty) = primitive::UintTy::from_name(name) {
                 return Ok(Ty::Uint(uint_ty));
-            } else if let Some(float_ty) = primitive::FloatTy::from_string(name) {
+            } else if let Some(float_ty) = primitive::FloatTy::from_name(name) {
                 return Ok(Ty::Float(float_ty));
             }
         }
diff --git a/crates/ra_hir/src/ty/primitive.rs b/crates/ra_hir/src/ty/primitive.rs
index ad79b17e4..498d42d52 100644
--- a/crates/ra_hir/src/ty/primitive.rs
+++ b/crates/ra_hir/src/ty/primitive.rs
@@ -1,5 +1,7 @@
 use std::fmt;
 
+use crate::{Name, KnownName};
+
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Copy)]
 pub enum IntTy {
     Isize,
@@ -34,14 +36,14 @@ impl IntTy {
         }
     }
 
-    pub fn from_string(s: &str) -> Option<IntTy> {
-        match s {
-            "isize" => Some(IntTy::Isize),
-            "i8" => Some(IntTy::I8),
-            "i16" => Some(IntTy::I16),
-            "i32" => Some(IntTy::I32),
-            "i64" => Some(IntTy::I64),
-            "i128" => Some(IntTy::I128),
+    pub fn from_name(name: &Name) -> Option<IntTy> {
+        match name.as_known_name()? {
+            KnownName::Isize => Some(IntTy::Isize),
+            KnownName::I8 => Some(IntTy::I8),
+            KnownName::I16 => Some(IntTy::I16),
+            KnownName::I32 => Some(IntTy::I32),
+            KnownName::I64 => Some(IntTy::I64),
+            KnownName::I128 => Some(IntTy::I128),
             _ => None,
         }
     }
@@ -69,14 +71,14 @@ impl UintTy {
         }
     }
 
-    pub fn from_string(s: &str) -> Option<UintTy> {
-        match s {
-            "usize" => Some(UintTy::Usize),
-            "u8" => Some(UintTy::U8),
-            "u16" => Some(UintTy::U16),
-            "u32" => Some(UintTy::U32),
-            "u64" => Some(UintTy::U64),
-            "u128" => Some(UintTy::U128),
+    pub fn from_name(name: &Name) -> Option<UintTy> {
+        match name.as_known_name()? {
+            KnownName::Usize => Some(UintTy::Usize),
+            KnownName::U8 => Some(UintTy::U8),
+            KnownName::U16 => Some(UintTy::U16),
+            KnownName::U32 => Some(UintTy::U32),
+            KnownName::U64 => Some(UintTy::U64),
+            KnownName::U128 => Some(UintTy::U128),
             _ => None,
         }
     }
@@ -120,10 +122,10 @@ impl FloatTy {
         }
     }
 
-    pub fn from_string(s: &str) -> Option<FloatTy> {
-        match s {
-            "f32" => Some(FloatTy::F32),
-            "f64" => Some(FloatTy::F64),
+    pub fn from_name(name: &Name) -> Option<FloatTy> {
+        match name.as_known_name()? {
+            KnownName::F32 => Some(FloatTy::F32),
+            KnownName::F64 => Some(FloatTy::F64),
             _ => None,
         }
     }