stagparser - generic parser for golang struct tag

Package stagparser provides a generic parser for golang struct tag. stagparser can parse tags like the following:

• validate:"required,length(min=1, max=10)"
• validate:"max=10,list=[apple,'star fruits']"

tags consist of 'definition'. 'definition' has 3 forms:

• name only: required
• name with a single attribute: max=10
  • in this case, parse result is name="max", attributes={"max":10}
• name with multiple attributes: length(min=1, max=10)

name and attribute must be a golang identifier. An attribute value must be one of an int64, a float64, an identifier, a string quoted by ' and an array.

• int64: 123
• float64: 111.12
• string: 'ab\tc'
  • identifiers are interpreted as string in value context
• array: [1, 2, aaa]

You can parse objects just calling ParseStruct:

import "github.com/yuin/stagparser"

type User struct {
  Name string `validate:"required,length(min=4,max=10)"`
}

func main() {
  user := &User{"bob"}
  definitions, err := stagparser.ParseStruct(user)
}

License

MIT

Author

Yusuke Inuzuka