From 03793e08d334dfdb3820bfb4ddeaaa494263d9b0 Mon Sep 17 00:00:00 2001
From: greg <greg.shuflin@protonmail.com>
Date: Wed, 20 Feb 2019 03:27:46 -0800
Subject: [PATCH] Typechecking operators

---
 schala-lang/language/src/builtin.rs      |  4 ++--
 schala-lang/language/src/typechecking.rs | 24 +++++++++++++++++++-----
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/schala-lang/language/src/builtin.rs b/schala-lang/language/src/builtin.rs
index 9d8683b..b05a532 100644
--- a/schala-lang/language/src/builtin.rs
+++ b/schala-lang/language/src/builtin.rs
@@ -30,12 +30,12 @@ impl BinOp {
     };
     Some(BinOp::from_sigil(s))
   }
-  /*
+
   pub fn get_type(&self) -> Result<Type, String> {
     let s = self.sigil.as_str();
     BINOPS.get(s).map(|x| x.0.clone()).ok_or(format!("Binop {} not found", s))
   }
-  */
+
   pub fn min_precedence() -> i32 {
     i32::min_value()
   }
diff --git a/schala-lang/language/src/typechecking.rs b/schala-lang/language/src/typechecking.rs
index b2d1888..01f39c1 100644
--- a/schala-lang/language/src/typechecking.rs
+++ b/schala-lang/language/src/typechecking.rs
@@ -250,7 +250,7 @@ impl<'a> TypeContext<'a> {
   fn prefix(&mut self, op: &PrefixOp, expr: &Expression) -> InferResult<Type> {
     let f = match op.get_type() {
       Ok(ty) => ty,
-      Err(e) => return TypeError::new("Couldn't find a type for this prefix op")
+      Err(e) => return TypeError::new(e)
     };
 
     let x = self.expr(expr)?;
@@ -258,14 +258,22 @@ impl<'a> TypeContext<'a> {
   }
 
   fn binexp(&mut self, op: &BinOp, lhs: &Expression, rhs: &Expression) -> InferResult<Type> {
-    Ok(ty!(Unit))
+    let tf = match op.get_type() {
+      Ok(ty) => ty,
+      Err(e) => return TypeError::new(e),
+    };
+
+    let t_lhs = self.expr(lhs)?;
+    let t_curried = self.handle_apply(tf, t_lhs)?;
+    let t_rhs = self.expr(rhs)?;
+    self.handle_apply(t_curried, t_rhs)
   }
 
   fn handle_apply(&mut self, tf: Type, tx: Type) -> InferResult<Type> {
     Ok(match tf {
-      Type::Arrow(ref t1, ref t2) => {
-        let _ = self.unify(*t1.clone(), tx)?;
-        *t2.clone()
+      Type::Arrow(box ref t1, box ref t2) => {
+        let _ = self.unify(t1.clone(), tx)?;
+        t2.clone()
       },
       _ => return TypeError::new(format!("Not a function"))
     })
@@ -348,4 +356,10 @@ mod typechecking_tests {
     assert_type_in_fresh_context!("-1", ty!(Int));
   }
 
+  #[test]
+  fn operators() {
+    assert_type_in_fresh_context!("1 + 2", ty!(Nat));
+    assert_type_in_fresh_context!("-2", ty!(Int));
+    assert_type_in_fresh_context!("!true", ty!(Bool));
+  }
 }