Before reading this: I'd recommend skimming Part 3's "Two-Phase Design" and "Block Scanner" sections to understand how the scanner outputs []Block. This post assumes you already know how the parser routes blocks to different parse functions based on their Title.
I. A Narrative Engine's Third Problem: How Do You Parse Condition-Action Rules?
Once the blocks are split, the most complex part is rule expressions. A narrative engine needs to answer: how are conditions written, how are actions written, and how are variables referenced?
There's an important design boundary here: the parser only parses, it doesn't evaluate. Condition strings like 包含 "攻击" && 状态.堕落指数 > 80 are stored as-is in the struct. The engine evaluates them at runtime. Why? Because the runtime state needed for evaluation doesn't exist at parse time — state values change dynamically during conversation and can't be determined at load time.
This post is about the parsing logic itself.
