let statements _within_ match patterns now need parens. adding sections to palette options. etc.

src/compiler.ts

@@ -38,9 +38,7 @@ export function compile(ast: AST, useStore = true, bound = new Set<string>(), to
             if (ast.func.kind === 'constructor') {
                 const ctorName = ast.func.name;
                 const arg = compile(ast.args[0], useStore, bound, topLevel);
-                return `((_a) => _a && typeof _a === 'object' && !Array.isArray(_a) && !_a._tag
-                         ? { _tag: "${ctorName}", ..._a }
-                         : { _tag: "${ctorName}", _0: _a })(${arg})`;
+                return `({ _tag: "${ctorName}", _0: ${arg} })`;
             }
 
             const args = ast.args.map(a => compile(a, useStore, bound, topLevel)).join(')(');