从表意的字符串中读取出运算逻辑 <!-- more --> ## 场景 watcher 中解析报警规则 ## 解释器模式 ![image.png|1000](https://imagehosting4picgo.oss-cn-beijing.aliyuncs.com/imagehosting/fix-dir%2Fpicgo%2Fpicgo-clipboard-images%2F2024%2F05%2F10%2F14-20-39-cec045e55094d9755275d1f28c3e06a4-20240510142038-c0b9b2.png) ![image.png|1000](https://imagehosting4picgo.oss-cn-beijing.aliyuncs.com/imagehosting/fix-dir%2Fpicgo%2Fpicgo-clipboard-images%2F2024%2F05%2F10%2F14-19-17-7d636330a7b3022509cfe513270ebb55-20240510141915-db23f4.png) Interpreter pattern is used to defines a grammatical representation for a language and provides an interpreter to deal with this grammar. 表达式的解析/规则引擎、定时任务中的 cron 表达式、ES 中的各种分词器