[eval]

eval is a core slot, one of the keywords of the Hyperlambda language, in Hyperlambda, the language of Magic Cloud. Executes a lambda block; use it to run a node tree dynamically or to scope a group of statements.

• Value (lambda-object,lambda-tree), optional: Expression selecting the Hyperlambda nodes to evaluate; alternatively supply literal executable children

Arguments

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

Argument	Type	Required	Description
any node name	lambda	no	Executable child slot evaluated in order. Can be repeated.

Guide: How to use [eval]

JSON declaration

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

JSON declaration

{
  "name": "eval",
  "description": "Executes a lambda block; use it to run a node tree dynamically or to scope a group of statements",
  "signature": {
    "input": {
      "kind": "lambda-object,lambda-tree",
      "description": "Expression selecting the Hyperlambda nodes to evaluate; alternatively supply literal executable children",
      "required": false,
      "mode": "Expression"
    },
    "children": {
      "*": {
        "type": "lambda",
        "description": "Executable child slot evaluated in order",
        "required": false,
        "mode": "ExecutableLambda",
        "cardinality": "ZeroOrMore",
        "role": "ExecutableBody",
        "evaluation": "EvalSelf",
        "projection": "Self"
      }
    }
  }
}

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