Function walk

walk(
    node: Expression,
    visitor: VisitorConfig,
    parent?: Expression | null,
    key?: string | null,
    index?: number | null,
): void
Walk an AST tree, calling visitor callbacks for each node
Parameters
- node: Expression
- visitor: VisitorConfig
- parent: Expression | null = null
- key: string | null = null
- index: number | null = null
Returns void
Example
```
walk(ast, {
  column: (node) => console.log('Found column:', getExprType(node)),
  enter: (node) => console.log('Entering:', getExprType(node)),
  leave: (node) => console.log('Leaving:', getExprType(node)),
});
```
- Defined in ast/visitor/walker.ts:101