fix: added missing conversions and generic inferring for coproducts

1 files changed, 14 insertions, 1 deletions

diff --git a/src/type/conversion.rs b/src/type/conversion.rs
index ab858e6..54fc59d 100644
--- a/src/type/conversion.rs
+++ b/src/type/conversion.rs
@@ -11,7 +11,7 @@ impl Type {
     /// 0. self == other => self
     /// 1. (T T ... T T) -> (T ...)
     /// 2. self = concrete and other = variable type => self,
-    /// 3. arrow types and lists are mapped
+    /// 3. arrow types and lists and sums are mapped
     /// 4. makes [self] self if self == other
     pub fn convert(self, other: &Type) -> Result<Type, ()> {
 	let (ty, ctx) = self.convert_ctx(other)?;
@@ -62,6 +62,14 @@ impl Type {
 		Ok((arr(t1, t2), ctx))
 	    },
 
+	    (SumType(a1, a2), SumType(b1, b2)) => {
+		let (t1, newctx) = a1.convert_ctx(b1)?;
+		ctx.extend(newctx);
+		let (t2, newctx) = a2.convert_ctx(b2)?;
+		ctx.extend(newctx);
+		Ok((sumtype(t1, t2), ctx))
+	    },
+
 	    (List(v), VecOf(ty)) => match v.get(0) {
 		Some(t) => {
 		    let (convt, newctx) = t.clone().convert_ctx(ty)?;
@@ -163,6 +171,11 @@ mod tests {
 		.convert(&arr(vt("T"), vt("T"))),
 	    Ok(arr(arr(vecof(Integer), Integer), arr(vecof(Integer), Integer)))
 	);
+	assert_eq!(
+	    sumtype(sumtype(vecof(Integer), Integer), sumtype(vecof(Integer), Integer))
+		.convert(&sumtype(vt("T"), vt("T"))),
+	    Ok(sumtype(sumtype(vecof(Integer), Integer), sumtype(vecof(Integer), Integer)))
+	);
 
 	assert!(
 	    List(vec![Integer, Boolean])