// Package expression provides types and functions to create Amazon DynamoDB
// Expression strings, ExpressionAttributeNames maps, and ExpressionAttributeValues
// maps.
//
// # Using the Package
//
// The package represents the various DynamoDB Expressions as structs named
// accordingly. For example, ConditionBuilder represents a DynamoDB Condition
// Expression, an UpdateBuilder represents a DynamoDB Update Expression, and so on.
// The following example shows a sample ConditionExpression and how to build an
// equilvalent ConditionBuilder
//
//	// Let :a be an ExpressionAttributeValue representing the string "No One You
//	// Know"
//	condExpr := "Artist = :a"
//	condBuilder := expression.Name("Artist").Equal(expression.Value("No One You Know"))
//
// In order to retrieve the formatted DynamoDB Expression strings, call the getter
// methods on the Expression struct. To create the Expression struct, call the
// Build() method on the Builder struct. Because some input structs, such as
// QueryInput, can have multiple DynamoDB Expressions, multiple structs
// representing various DynamoDB Expressions can be added to the Builder struct.
// The following example shows a generic usage of the whole package.
//
//	filt := expression.Name("Artist").Equal(expression.Value("No One You Know"))
//	proj := expression.NamesList(expression.Name("SongTitle"), expression.Name("AlbumTitle"))
//	expr, err := expression.NewBuilder().WithFilter(filt).WithProjection(proj).Build()
//	if err != nil {
//	  fmt.Println(err)
//	}
//
//	input := &dynamodb.ScanInput{
//	  ExpressionAttributeNames:  expr.Names(),
//	  ExpressionAttributeValues: expr.Values(),
//	  FilterExpression:          expr.Filter(),
//	  ProjectionExpression:      expr.Projection(),
//	  TableName:                 aws.String("Music"),
//	}
//
// The ExpressionAttributeNames and ExpressionAttributeValues member of the input
// struct must always be assigned when using the Expression struct because all item
// attribute names and values are aliased. That means that if the
// ExpressionAttributeNames and ExpressionAttributeValues member is not assigned
// with the corresponding Names() and Values() methods, the DynamoDB operation will
// run into a logic error.
//
// Deprecated: aws-sdk-go is deprecated. Use aws-sdk-go-v2.
// See https://aws.amazon.com/blogs/developer/announcing-end-of-support-for-aws-sdk-for-go-v1-on-july-31-2025/.
package expression