JSON to classes with Ollama

Overview

DartJ, a website I built, specializes in converting JSON into class models for Dart, Swift, and Kotlin. The fundamental mechanism behind this conversion is a depth-first tree traversal algorithm.

Now, I’m presenting a novel approach that leverages Ollama to transform JSON into class/struct models for a specified programming language, with the generated code being outputted to a file

Demo

Ollma Setup

Ollama Install & Pull model

% ollama ls
NAME                    ID              SIZE      MODIFIED          
qwen2.5-coder:latest    2b0496514337    4.7 GB    About an hour ago    
codellama:13b           9f438cb9cd58    7.4 GB    3 days ago           
codegemma:7b            0c96700aaada    5.0 GB    3 days ago           

Build System prompt

"""
I am a $lang developer.
I give you a JSON string, convert it to $lang classess. 
I want you to only reply the correction, do not write explanations.

For example, my JSON string

${jsonAndClass.$1}

You will convert it to $lang classes 

${jsonAndClass.$2}

"""

Excute Ollma

• LLM model: $model
• System promt: $sytemPrompt
• Json resource: $json

curl http://localhost:11434/api/chat -d '{
  "model": $model,
  "messages": [
    {
      "role": "assistant",
      "content": $sytemPrompt
    },
    {
      "role": "user",
      "content": $json
    }
  ]
}'

Parser result

  String llmToCode(String language, String codeContent) {
    final prefix = '```$language';
    final start = codeContent.indexOf(prefix);
    final end = codeContent.lastIndexOf('```');

    if (start == -1 || end == -1) {
      return codeContent;
    }
    return codeContent.substring(start + prefix.length, end).trim();
  }