[try]

try is a core slot, one of the keywords of the Hyperlambda language, in Hyperlambda, the language of Magic Cloud. Evaluates the protected body; pair with [.catch] to handle exceptions and/or [.finally] to always run cleanup.

• Scope: provides try

Arguments

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

Argument	Type	Required	Description
any node name	lambda	no	Protected body evaluated by [try]. Can be repeated.

Constraints

• NextSiblingMustBeOneOf: Must be followed by [.catch] and/or [.finally]; a bare [try] is a no-op because uncaught exceptions re-throw and [.finally] alone would run regardless ([.catch], [.finally])

Guide: How to use [try]

JSON declaration

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

JSON declaration

{
  "name": "try",
  "description": "Evaluates the protected body; pair with [.catch] to handle exceptions and/or [.finally] to always run cleanup",
  "signature": {
    "children": {
      "*": {
        "type": "lambda",
        "description": "Protected body evaluated by [try]",
        "required": false,
        "mode": "ExecutableLambda",
        "cardinality": "ZeroOrMore",
        "role": "ExecutableBody",
        "evaluation": "EvalSelf",
        "projection": "Self"
      }
    },
    "constraints": [
      {
        "description": "Must be followed by [.catch] and/or [.finally]; a bare [try] is a no-op because uncaught exceptions re-throw and [.finally] alone would run regardless",
        "values": [
          ".catch",
          ".finally"
        ],
        "kind": "NextSiblingMustBeOneOf"
      }
    ],
    "scope": {
      "provides": "try"
    }
  }
}

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