[map]

map is a core slot, one of the keywords of the Hyperlambda language, in Hyperlambda, the language of Magic Cloud. Maps selected nodes into a new result set using the child lambda.

• Value (node-list), required: Expression selecting the nodes to map
• Returns: Resolves to one mapped output item per selected node, using the value or nodes returned by the child lambda

Arguments

Required arguments come first, then the optional ones in the order they are declared.

Argument	Type	Required	Description
any node name	lambda	yes	Mapper body evaluated once per selected node; each returned value becomes a [.] node and returned child nodes are added to the mapped result. Can be repeated.

Guide: How to use [map]

JSON declaration

This is the complete declaration of map, as the running system describes it. It is also published as slot.json.

JSON declaration

{
  "name": "map",
  "description": "Maps selected nodes into a new result set using the child lambda",
  "signature": {
    "input": {
      "kind": "node-list",
      "description": "Expression selecting the nodes to map",
      "required": true,
      "mode": "Expression"
    },
    "children": {
      "*": {
        "type": "lambda",
        "description": "Mapper body evaluated once per selected node; each returned value becomes a [.] node and returned child nodes are added to the mapped result",
        "required": true,
        "mode": "ExecutableLambda",
        "cardinality": "OneOrMore",
        "role": "ExecutableBody",
        "evaluation": "EvalSelf",
        "projection": "ReturnedResult"
      }
    },
    "output": {
      "mode": "Lambda",
      "kind": "node-list",
      "description": "Resolves to one mapped output item per selected node, using the value or nodes returned by the child lambda"
    }
  }
}

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