MakeObj - A JSON Generator!

This is a small tool to generate JSON objects from definitions.

Introduction

Let us start with what it can do!

$ makeobj -p "{students: [{grade: 1 to 5, name: /[A-Z][a-z]{3,5}/}]}"
{
    "students": [
        {
            "name": "Lzcl",
            "grade": 5
        },
        {
            "name": "Otfm",
            "grade": 5
        },
        {
            "name": "Ragtoo",
            "grade": 4
        },
        {
            "name": "Zbyipc",
            "grade": 4
        }
}

As you see, we gave a definition and it generated a JSON blob conforming to the generated form. It was neatly formatted because of the -p flag!

You can also create premade definitions by making a file in the folder ~/.makeobj/ with the extension .defs.

For instance, if we have a file called ~/.makeobj/Friends.defs

Friend = /(Ha|Si|Poké)mon (Gunnar|Anders|Jesper|Saftar)sson/

We can generate an object using the below syntax

$ makeobj Friend
"Pokémon Gunnarsson"

This makes it easy for us to create complex structures:

~/.makeobj/School.defs

Name = /(Ha|Si|Poké)mon (Gunnar|Anders|Jesper|Saftar)sson/
Grade = 1 to 5
Person = { name: Name }

Student = { name: Name
          , grade: Grade
          }

School = { teacher: Person
         , class: 
           { courseName: /(Philosoph|Letharg)y/
           , students: list of Student
           }
         }

Let us try it out:

$ makeobj School
{"teacher":{"name":"Hamon Jespersson"},"class":{"courseName":"Lethargy","students":[{"name":"Pokémon Anderssson","grade":1},{"name":"Pokémon Anderssson","grade":2},{"name":"Hamon Saftarsson","grade":2},{"name":"Simon Gunnarsson","grade":4},{"name":"Simon Saftarsson","grade":3},{"name":"Simon Gunnarsson","grade":5},{"name":"Simon Jespersson","grade":2}]}}

Syntax Specification

Simple generators

Regexes

Syntax: /Regular Expression/

Example /[a-z]{2}_[A-Z]{2}/

Generates a string from a regular expression.

Type labels

Syntax: TypeLabel

Example: Car

Generates a symbol from a predefined definition.

Literals

Syntax: Literal

Example: true, null, 10.22, "Hagrid", 1985-10-25

Constructs a literal in the current generator. Supports boolean, null, numbers, strings and ISO8601 datetimes.

Lists

Syntax: [Generator1, Generator2, ...]

Example: [Car, Car, "Hagrid", Car]

Constructs a list with the given generators.

Complex generators

Lists

Syntax: list of Generator, Int of Generator, Int to Int of Generator

Example: [/(Harry|Hagrid) from (Hogwarts|a shed)/], 5 of 9 to 17, 1 to 5 of /a+/

Generates a list of elements from a generator.

Objects

Syntax: {}, {field: Generator}, {fieldA: Generator, fieldB: Generator}

Example: {name: /(Harry|Hagrid)/, from: /(Hogwarts|a shed)/}

Generates an JSON compatible object.

Ranges

Syntax: Int to Int, Float to Float, ISO8601 to ISO8601

Example: 1 to 5, 0.0 to 1.0, 2014-12-25 to 2018-12-26

Generates a number from an inclusive range of symbols. Currently supports integers, floats and date ranges.

Contribute

I'll happily accept any contributions to the project, even if it's just a feature request in an issue!