type:      seq
sequence:
  -
    type:      map
    mapping:
     "name":
        type:       str
        required:   yes
     "email":
        type:       str
        required:   yes
        pattern:    /@/
     "password":
        type:       text
        length:     { max: 16, min: 8 }
     "age":
        type:       int
        range:      { max: 30, min: 18 }
        # or assert: 18 <= val && val <= 30
     "blood":
        type:       str
        enum:       [A, B, O, AB]
     "birth":
        type:       date
     "memo":
        type:       any
     "deleted":
        type:       bool
        default:    false
