Pattern matching is also useful for the design problem where you need to get at data inside an object, but only in special circumstances.

在你遇到需要从对象内部提取数据的设计问题时，模式匹配也有用，但是仅限一些特殊的情况。

youdao

This makes pull useful only in situations where the data is published frequently according to some pattern...

这使得拉取方式只有在数据是根据某种特定模式发布的情况才 有用。

youdao

While an index on a relational column contains all values from that column, an XML index contains only values of nodes that match both the XML pattern and the data type in the index definition.

关系列上的索引包含了此列的所有值，而xml索引仅包含那些同时匹配XML模式和索引定义中的数据类型的节点值。

youdao

For example, what if there is some, pattern in nature or human behavior that only becomes visible after we begin looking at octillions of bits of sensory data and what if that pattern proves a revelation about humanity or the natural world?

FORBES: Welcome to the Real World