product-farm-json-logic

High-performance JSON Logic implementation with bytecode compilation and a register-based VM.

Overview

product-farm-json-logic is a blazing-fast JSON Logic evaluator featuring:

• Tiered execution - AST interpretation for simple rules, bytecode for complex ones
• Bytecode compiler - Compiles JSON Logic to optimized bytecode
• Register-based VM - Executes bytecode with minimal overhead
• 3.5x faster than pure AST interpretation
• ~330ns per evaluation for compiled rules

Performance

Conditional Rules

Part of Product-FARM

This crate is part of Product-FARM, an enterprise-grade rule engine featuring:

• Natural language YAML - Define rules in human-readable format
• LLM-powered evaluation - Use Claude or Ollama for complex rule interpretation
• DAG execution - Automatic dependency resolution
• 1 million rules tested at 96k rules/sec

Installation

[dependencies]
product-farm-json-logic = "0.2"

Usage

use product_farm_json_logic::{JsonLogicEvaluator, CachedExpression};
use product_farm_core::Value;
use serde_json::json;

// Create an evaluator
let mut evaluator = JsonLogicEvaluator::new();

// Parse and cache an expression (auto-compiles to bytecode if complex)
let expr = CachedExpression::new(json!({
    "if": [
        {"<": [{"var": "age"}, 25]},
        {"*": [{"var": "base_rate"}, 1.5]},
        {"<": [{"var": "age"}, 35]},
        {"*": [{"var": "base_rate"}, 1.2]},
        {"var": "base_rate"}
    ]
}));

// Evaluate with data
let data = Value::Object(hashbrown::HashMap::from([
    ("age".into(), Value::Number(30.0)),
    ("base_rate".into(), Value::Number(100.0)),
]));

let result = evaluator.evaluate_cached_value(&expr, &data)?;
// result = 120.0 (base_rate * 1.2 for age 30)

Supported Operations

Arithmetic

+, -, *, /, %, min, max

Comparison

==, !=, <, <=, >, >=, ===, !==

Logic

and, or, !, !!, if, ?:

String

cat, substr, in

Array

map, filter, reduce, all, some, none, merge

Data Access

var, missing, missing_some

Architecture

JSON Logic Expression
        │
        ▼
   ┌─────────┐
   │  Parser │ ──────► AST
   └─────────┘
        │
        ▼ (if nodes > 5)
   ┌──────────┐
   │ Compiler │ ──────► Bytecode
   └──────────┘
        │
        ▼
   ┌─────────┐
   │   VM    │ ──────► Result
   └─────────┘

Related Crates

Documentation

• Product-FARM Documentation
• API Reference
• JSON Logic Specification

License

MIT License - see LICENSE for details.