php Xiaobian Yuzai introduces to you "go: field definitions of parts other than name and type". In the Go language, in addition to the name and type of the field, other attributes and labels can be defined for the field. You can control a field's visibility and access by adding properties to it. By adding tags to fields, you can add additional metadata to the fields to describe the characteristics of the fields. These field definitions can be used in structures, providing more flexibility and scalability for program design and implementation.
I saw this structure definition:
type Resource struct { Attrs []Attribute `parquet:",list"` ServiceName string `parquet:",snappy,dict"` Cluster *string `parquet:",snappy,optional,dict"` .... }
I understand the first two parts of the field definition (name, type). But what does that last part mean? like
parquet:",snappy,dict"
Text in backticks describes Go structure tags that can be accessed via reflection (see reflect.StructTag
for details).
These tags are typically used by codes that marshal/unmarshal into different formats - usually describing how a field should be decoded or encoded. Usage of the structure tag of encoding/json
for the Marshal
and Unmarshal
functions.
Your example appears to be related to the github.com/segmentio/parquet-go
package. It has some brief documentation on how the package interprets structure tags .
in particular:
snappy
Encode columns using Snappy compressiondict
Enable Dict encoded files using Parquet. Optional
Indicates that the Parquet column is optional. list
indicates that the parquet LIST logical type should be used. The above is the detailed content of go: Field definition of parts other than name and type. For more information, please follow other related articles on the PHP Chinese website!