Iterator

[data/tree/Iterator]

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Iterates over nodes in a tree (deeply nested object) structure, as specified by the query. The query acts as a filter for the iteration. It could hold strings for object keys, numbers for array indices, or objects describing either catch-all or a set of keys to include. An example query: ["foo", 1, {"type":"wildcard"}, {"type":"options", "options": ["bar", "baz"]}] Example:

1. {"foo": [0, {"a": { "bar": 1 }, "b": { "baz": 1 }}]}@0 is received via tree

2. ["foo", 1, {"type":"wildcard"}, {"type":"options", "options": ["bar", "baz"]}]@0 is received via query

3. ["foo", 1, "a", "bar"]@0:0 is sent via path

4. 1@0:0 is sent via node

5. the original tree is sent via tree

6. ["foo", 1, "a", "baz"]@0:1 is sent via path

7. 1@0:1 is sent via node

8. the original tree is sent via tree

9. null@0 is sent via done

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Keywords: tree, iterator, foreach

Input ports

• tree: (any[] or {string: any})

  The tree data structure to iterate over on.

• query:

  (
    string
    or number
    or {"type": "wildcard"}
    or {"type": "options", "options": (string[] or number[])}
  )[]

  Pattern for paths. Array of strings, numbers or expressions. Strings look for exact matches, numbers for array indices and expressions describe matching mechanisms. {"type": "wildcard"} Matches any key in the current node. {"type": "options", "options":[]} Matches the listed keys.

Output ports

• path: (string or number)[]

  Sends the current path in the iteration

• node: any

  Sends the current node in the iteration

• tree: (any[] or {string: any})

  Sends the entire tree

• done: null

  Sends null when the iteration is done