Add expand as a filter to dap?

[ssikdar1]

Currently in dap:

$ echo '{"id": 1, "info.name":"jon snow", "info.dead": false, "info.age": 29}' | dap json + expand info + json
{"id":1,"info.name":"jon snow","info.dead":false,"info.age":29,"info":{"name":"jon snow","dead":false,"age":29}}

However trying go dap:

$ echo '{"id": 1, "info.name":"jon snow", "info.dead": false, "info.age": 29}' | ./dappy json + expand info + json
Error: Invalid filter plugin: expand

We probably could use some variation of this script (inspiration taken from the dap) in ./filter/simple.go:

package main

import (
    "fmt"
    "os"
    "io/ioutil"
    "regexp"
    "encoding/json"
)

func main() {

   bytes, _ := ioutil.ReadAll(os.Stdin)

   myMap := make(map[string]interface{})
   _ = json.Unmarshal([]byte(bytes), &myMap)

   pattern := fmt.Sprintf("^%s\\.(?P<sub_key>.+)$", os.Args[1])
   r := regexp.MustCompile(pattern)

   tmp := make(map[string]interface{})
   for k, v := range myMap {
      match :=  r.FindStringSubmatch(k)
      if(len(match) > 0){
         tmp[match[1]] =  v
      }
   }
   myMap[os.Args[1]] =  tmp

   jsonString, _ := json.Marshal(myMap)
   fmt.Println(string(jsonString))

}

sample run:

$ echo '{"id": 1, "info.name":"jon snow", "info.dead": false, "info.age": 29}' | dap json + expand info + json
{"id":1,"info.name":"jon snow","info.dead":false,"info.age":29,"info":{"name":"jon snow","dead":false,"age":29}}