Aggregation Expression - $exp

Function Build

Build $exp with the Exp function from the aggregation package.

// bson.D{bson.E{Key:"result", Value:bson.D{bson.E{Key:"$exp", Value:"$power"}}}}
result := aggregation.Exp("result", "$power")

Method Build (Builder)

Build $exp with the Exp method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"result", Value:bson.D{bson.E{Key:"$exp", Value:"$power"}}}}
result := aggregation.NewBuilder().
    Exp("result", "$power").
    Build()

Build Without Key

When an expression needs to be passed as an argument to another expression, use a WithoutKey variant to build an expression fragment without an output field name.

ExpWithoutKey

This variant is currently available as a builder method.

Method build (Builder):

// bson.D{bson.E{Key:"$exp", Value:"$power"}}
expr := aggregation.NewBuilder().
    ExpWithoutKey("$power").
    Build()