Map Operation

Example.json

// Sample Event Stream:
{ "event_type": "identification", "name": "nachos" }
{ "event_type": "event", "data": {"meat_type": "carnitas", "cheese_temp": 103, "vegetables": ["tomatoes", "olives"] } }
{ "event_type": "event", "data": {"meat_type": "beef", "cheese_temp": 101, "vegetables": ["tomatoes", "olives"] } }
{ "event_type": "event", "data": {"meat_type": "chicken", "cheese_temp": 98, "vegetables": ["tomatoes", "olives"] } }


// Sample Query:
{
    "stream_id" : "nachos",
    "stages": 
        [
            {
                 "query_type": "map",
                 "key": "cheese_temp",
                 "result_key": "cheese_temp_celsius",
                 "operation": "(value - 32) * (5/9)"
            }
        ]
}

// Sample results:
{ "meat_type": "carnitas", "cheese_temp": 103, "vegetables": ["tomatoes", "olives"], "cheese_temp_celsius":39.44444444444444 }
{ "meat_type": "beef", "cheese_temp": 101, "vegetables": ["tomatoes", "olives"], "cheese_temp_celsius":38.333333333333336 }
{ "meat_type": "chicken", "cheese_temp": 98, "vegetables": ["tomatoes", "olives"], "cheese_temp_celsius":36.66666666666667 }