使用Map进行Groovy多重赋值

Question

我在使用map时遇到了一个问题，即如何进行多重赋值语句。

def map = [a:1,b:2]
(map.a, map.b) = [3,4]

这会抛出一个异常：

expecting ')', found ',' at line: 2, column: 7

然而，这个可以正常运行：

def a = 1
def b = 2
(a, b) = [3,4]

- David Sawyer

Answer 1

实际上，如果您使用.with进行欺骗，那么您可以做到这一点：

Map map = [a: 1, b:2]

map.with {
    (a, b) = [3, 4]
}

assert map.a == 3
assert map.b == 4

- Igor

---

哇，那是个巧妙的解决办法。那个方案可行，Igor！ - David Sawyer

Answer 2

它不支持那个。 http://groovy.codehaus.org/Multiple+Assignment

currently only simple variables may be the target of multiple assignment expressions, e.g.if you have a person class with firstname and lastname fields, you can't currently do this:

(p.firstname, p.lastname) = "My name".split()

- evanwong