Add left/right type to TupleType

Author: rkalis

packages/cashc/src/semantic/TypeCheckTraversal.ts

@@ -168,7 +168,8 @@ export default class TypeCheckTraversal extends AstTraversal {
       throw new IndexOutOfBoundsError(node);
     }
 
-    node.type = (node.tuple.type as TupleType).elementType;
+    node.type = node.index === 0 ? (node.tuple.type as TupleType).leftType : (node.tuple.type as TupleType).rightType;
+
     return node;
   }
 
@@ -243,6 +244,7 @@ export default class TypeCheckTraversal extends AstTraversal {
         // Result of split are two unbounded bytes types (could be improved to do type inference)
         node.type = new TupleType(
           node.left.type instanceof BytesType ? new BytesType() : PrimitiveType.STRING,
+          node.left.type instanceof BytesType ? new BytesType() : PrimitiveType.STRING,
         );
         return node;
       default:
@@ -371,7 +373,9 @@ function expectSameSizeBytes(node: BinaryOpNode, left?: Type, right?: Type): voi
 
 function expectTuple(node: ExpectedNode, actual?: Type): void {
   if (!(actual instanceof TupleType)) {
-    throw new UnsupportedTypeError(node, actual, new TupleType());
+    // We use a placeholder tuple to indicate that we're expecting *any* tuple at all
+    const placeholderTuple = new TupleType(new BytesType(), new BytesType());
+    throw new UnsupportedTypeError(node, actual, placeholderTuple);
   }
 }
 

packages/utils/src/types.ts

@@ -4,7 +4,7 @@ export class ArrayType {
   constructor(
     public elementType: Type,
     public bound?: number,
-  ) {}
+  ) { }
 
   toString(): string {
     return `${this.elementType}[${this.bound ?? ''}]`;
@@ -14,7 +14,7 @@ export class ArrayType {
 export class BytesType {
   constructor(
     public bound?: number,
-  ) {}
+  ) { }
 
   static fromString(str: string): BytesType {
     const bound = str === 'byte' ? 1 : Number.parseInt(str.substring(5), 10) || undefined;
@@ -28,11 +28,12 @@ export class BytesType {
 
 export class TupleType {
   constructor(
-    public elementType?: Type,
-  ) {}
+    public leftType: Type,
+    public rightType: Type,
+  ) { }
 
   toString(): string {
-    return `(${this.elementType}, ${this.elementType})`;
+    return `(${this.leftType}, ${this.rightType})`;
   }
 }