feat: generic match arms, mostly for functions I guess?

4 files changed, 13 insertions, 6 deletions

diff --git a/src/type/check.rs b/src/type/check.rs
index 7a2d231..f842b4c 100644
--- a/src/type/check.rs
+++ b/src/type/check.rs
@@ -216,7 +216,14 @@ impl SExp {
     /// };
     /// ```
     pub fn type_check(&self) -> Result<Type, TypeError> {
-        self.infer_type(HashMap::new())
+	let res = self.infer_type(HashMap::new());
+	match res {
+	    Ok(res) => match res.is_concrete() {
+		Ok(()) => Ok(res),
+		Err(name) => Err(UnboundGeneric(name)),
+	    },
+	    e => e,
+	}
     }
 
 
@@ -305,10 +312,7 @@ impl SExp {
 			}
 			match &ty {
 			    None => ty = Some(arm.infer_type(newctx)?),
-			    Some(t) => if arm.infer_type(newctx.clone())? != *t {
-				println!("different types: {}, {}", t, arm.infer_list_type(newctx)?);
-				           return Err(OtherError);
-				       },
+			    Some(t) => ty = Some(t.least_general_supertype(&arm.infer_type(newctx.clone())?)),
 			}
 		    }
 		    if !has_wildcard {
diff --git a/src/type/conversion.rs b/src/type/conversion.rs
index 0a96790..5d29ba0 100644
--- a/src/type/conversion.rs
+++ b/src/type/conversion.rs
@@ -30,7 +30,7 @@ impl Type {
 	self.least_general_supertype(known_as) == *known_as
     }
 
-    fn least_general_supertype(&self, other: &Type) -> Type {
+    pub fn least_general_supertype(&self, other: &Type) -> Type {
 
 	match (self, other) {
 
diff --git a/src/type/display.rs b/src/type/display.rs
index 290e24e..56b22b6 100644
--- a/src/type/display.rs
+++ b/src/type/display.rs
@@ -122,6 +122,7 @@ impl fmt::Display for TypeError {
                     letexp
                 )
             },
+	    DifferentTypeCaseArms(ty1, ty2) => write!(f, "arms of match have different types, '{ty1}' and '{ty2}'"),
 	    FunAsAtom => write!(f, "'fn' used as atom doesn't make sense"),
 	    CaseAsAtom => write!(f, "'case' used as atom doesn't make sense"),
 	    RestAsAtom => write!(f, "'..[name]' used as atom doesn't make sense"),
diff --git a/src/type/mod.rs b/src/type/mod.rs
index e979595..06b73ac 100644
--- a/src/type/mod.rs
+++ b/src/type/mod.rs
@@ -79,6 +79,8 @@ pub enum TypeError {
 
     NoWildcardInCase(SExp),
 
+    DifferentTypeCaseArms(Type, Type),
+
     OtherError
 }