encodingxml

Encoding/xml is a package in the Go programming language's standard library that provides support for encoding and decoding XML data. It offers a streaming API for reading XML from a reader and for writing XML to a writer, as well as convenience helpers for marshaling and unmarshaling Go values to and from XML.

Core capabilities include decoding XML into Go structs or generic data structures; marshaling Go values into XML; and a token-based parser (Decoder) and writer (Encoder). The package provides functions such as Unmarshal, Marshal, and MarshalIndent, and defines types like xml.Name, StartElement, EndElement, CharData, and Comment to model XML constructs. Struct field tags (for example, xml:"name" or xml:"ns:name" and xml:",attr" to mark attributes) control how the mapping between XML elements and Go struct fields is performed. Only exported fields are serialized by default. The package also supports basic namespace handling via XML prefixes in tags.

Usage typically involves declaring Go structs with appropriate xml tags, then calling Unmarshal to populate them from XML, or using Marshal/MarshalIndent to produce XML. For large documents, the streaming Decoder helps avoid loading the entire document into memory and supports incremental parsing.

Limitations include its focus on a straightforward XML-to-Go mapping rather than a full DOM or comprehensive XML processing toolkit. It may require workarounds for complex namespaces, mixed content, or preserving non-struct data such as comments in certain scenarios.

See also: Go programming language; encoding package; XML; data serialization formats.