[source, ruby]
----
response = client.search(
  body: {
    runtime_mappings: {
      'amount.signed' => {
        type: 'double',
        script: "\n        double amount = doc['amount'].value;\n        if (doc['type'].value == 'expense') {\n          amount *= -1;\n        }\n        emit(amount);\n      "
      }
    },
    query: {
      bool: {
        filter: {
          range: {
            'amount.signed' => {
              lt: 10
            }
          }
        }
      }
    },
    fields: [
      {
        field: 'amount.signed'
      }
    ]
  }
)
puts response
----
