编译或运行指示

从nim语言借鉴学习
```nim
{.指示.}
//多个指示
{.使用变量默认值. , .数组切片不包含末尾.}
```

The issue mentions borrowing a directive/pragma syntax from Nim. First, examine the existing compiler code to understand how language features are currently parsed and processed. Look for where similar annotations or compiler flags might be added. Determine what '使用变量默认值' and '数组切片不包含末尾' would mean in the context of Simple-language's dynamic type system. A newcomer would need to understand the compiler's architecture first.

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