java - 贪心量词

Question

我在阅读 K.Sierra 时发现了以下句子:

The greedy quantifier does in fact read the entire source data, and then it works backward (from the right) until it finds the rightmost match. At that point, it includes everything from earlier in the source data up to and including the data that is part of the rightmost match.

现在，假设我们有如下来源:

"proj3.txt,proj1sched.pdf,proj1,proj2,proj1.java"

和模式:proj1([^,])*

为什么它与全文不匹配？由于贪婪，它应该匹配最右边的“proj1.java”，并且返回的匹配应该是最右边匹配之前的整个源？相反，它返回:

proj1sched.pdf
proj1
proj1.java

Answer 1

why doesn't it match the whole text?

因为您声明它必须以 proj1 开头

Being greedy it should have match the rightmost "proj1.java"

正确。

and the returned match should have been the entire source before the right most match?

不知道你为什么会这么想，或者为什么这会有用。如果您想要的话，您可以只执行 .*proj1.* 。