有序流上的减少是按顺序减少的吗？
我有一个列表的A，B，C。
I have a List of A, B, C.
C减少A减少B！= A减少B减少C （但是，减少（B减少C）是可以的）。
C reduce A reduce B != A reduce B reduce C (however, A reduce (B reduce C) is OK).
换句话说，我的缩减操作是关联的但不是可交换的。
In other words, my reduction operation is associative but not commutative.
java是否对有序顺序执行流（例如列表中的默认值）是否会根据遭遇顺序进行减少？也就是说，java会重新排序减少（这样B减少A而不是A减少B）？
Does java enforce on an ordered sequential stream (such as the default one from a list) that reduction will always happen according to the encounter order? That is to say, will java reorder reductions (such that B reduce A instead of A reduce B)?
（希望这很清楚）。
编辑添加一个小演示，可能有助于澄清
edit to add a little demo and maybe helping to clarify
Stream.of(" cats ", " eat ", " bats ")
.reduce("", (a, b) -> a + b); // cats eat bats
有了上述，输出可能是蝙蝠猫吃或吃蝙蝠猫？是否保证在规范的某个地方？
With the above, could the output ever be "bats cats eat" or "eat bats cats"? Is that guaranteed somewhere in the spec?
我以前的回答是不正确的（感谢@shmosel纠正我）。
My previous answer was incorrect (thanks to @shmosel for correcting me).
现在我说，根据规范，它尊重元素的顺序。
Now I state, that according to the specification it respects the order of the elements.
证明非常简单。 规范声称缩减函数必须 关联。
Proof is very simple. The specification claims that a reduction function has to be associative.
然而， 关联性 如果不保留订单，那么它自身没有任何意义。根据关联属性的数学定义：
在
行中包含两个或多个匹配项的表达式中，相同的关联运算符，执行
的操作顺序无关紧要只要操作数的顺序是
未更改。
换句话说，关联属性并不意味着：
In other words, associative property doesn't imply that:
(a + b) + c = (a + c) + b
它只允许对应用操作的顺序进行任意排列。
It only allows arbitrary permutation of the order in which operations are applied.