Luadata by Example: Empty Table Modes

The WithEmptyTableMode option controls how empty Lua tables are rendered in JSON. There are four modes to choose from.

Given this input:

lua

data = {}

EmptyTableNull (default) renders as null:

json

{
  "data": null
}

EmptyTableOmit removes the key entirely:

json

{}

EmptyTableArray renders as an empty JSON array:

json

{
  "data": []
}

EmptyTableObject renders as an empty JSON object:

json

{
  "data": {}
}

package main

import (
    "fmt"
    "io"

    "github.com/mmobeus/luadata"
)

func main() {
    input := `data = {}`

    reader, err := luadata.TextToJSON("input", input,
        luadata.WithEmptyTableMode("array"),
    )
    if err != nil {
        panic(err)
    }
    result, _ := io.ReadAll(reader)
    fmt.Println(string(result))
}

output

{
  "data": []
}

From the CLI, use the --empty-table flag:

bash

echo 'data = {}' | luadata tojson --empty-table=object -

output

{
  "data": {}
}

Want more flexibility? Open the interactive converter to try any Lua input with all available options.

← Empty Tables Array Detection →