Aggregation Expression - $map

Function Build

Build $map with the Map function from the aggregation package.

// bson.D{bson.E{Key:"scoreLabels", Value:bson.D{bson.E{Key:"$map", Value:bson.D{bson.E{Key:"input", Value:"$scores"}, bson.E{Key:"as", Value:"score"}, bson.E{Key:"in", Value:bsonx.D("$toString", "$$score")}}}}}}
result := aggregation.Map("scoreLabels", "$scores", "score", bsonx.D("$toString", "$$score"))

Method Build (Builder)

Build $map with the Map method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"scoreLabels", Value:bson.D{bson.E{Key:"$map", Value:bson.D{bson.E{Key:"input", Value:"$scores"}, bson.E{Key:"as", Value:"score"}, bson.E{Key:"in", Value:bsonx.D("$toString", "$$score")}}}}}}
result := aggregation.NewBuilder().
    Map("scoreLabels", "$scores", "score", bsonx.D("$toString", "$$score")).
    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.

MapWithoutKey

Function build:

// bson.D{bson.E{Key:"$map", Value:bson.D{bson.E{Key:"input", Value:"$scores"}, bson.E{Key:"as", Value:"score"}, bson.E{Key:"in", Value:bsonx.D("$toString", "$$score")}}}}
expr := aggregation.MapWithoutKey("$scores", "score", bsonx.D("$toString", "$$score"))

Method build (Builder):

// bson.D{bson.E{Key:"$map", Value:bson.D{bson.E{Key:"input", Value:"$scores"}, bson.E{Key:"as", Value:"score"}, bson.E{Key:"in", Value:bsonx.D("$toString", "$$score")}}}}
expr := aggregation.NewBuilder().
    MapWithoutKey("$scores", "score", bsonx.D("$toString", "$$score")).
    Build()