if(t->type == TOK_COLON) {
if(LEFT(t)) genExpr(p, LEFT(t)); else emit(p, OP_PUSHNIL);
if(RIGHT(t)) genExpr(p, RIGHT(t)); else emit(p, OP_PUSHNIL);
if(t->type == TOK_COLON) {
if(LEFT(t)) genExpr(p, LEFT(t)); else emit(p, OP_PUSHNIL);
if(RIGHT(t)) genExpr(p, RIGHT(t)); else emit(p, OP_PUSHNIL);