Fixing constraint bug, pretty printing constraints

src/ast.ts

@@ -344,7 +344,9 @@ export function prettyPrint(ast: AST, indent = 0): string {
 
         case 'definition':
             const ann = ast.annotation
-                ? ` : ${prettyPrintType(ast.annotation.type)}`
+                ? ` : ${ast.annotation.constraints.length > 0
+                    ? ast.annotation.constraints.map(c => `${c.className} ${c.typeVar}`).join(', ') + ' :: '
+                    : ''}${prettyPrintType(ast.annotation.type)}`
                 : '';
             if (!ast.body) return `${ast.name}${ann};`;
             return `${ast.name}${ann} = ${prettyPrint(ast.body, indent)};`;