in src/langs/swift/combinator.js [633:644]
grammerExpr(emitter, gram, ignoreCast) {
if (!gram.left && !gram.right) {
emitter.emit(` ${_symbol(gram.opt)} `);
return;
}
this.grammer(emitter, gram.left, false, false);
emitter.emit(` ${_symbol(gram.opt)} `);
this.grammer(emitter, gram.right, false, false);
if (gram.as && !ignoreCast) {
emitter.emit(` as! ${this.emitType(gram.as.type)}`);
}
}