Bindings - rulii Documentation

A Binding is a named, typed variable. A Bindings container holds multiple bindings and acts as the shared workspace for rules — conditions read from it, and actions write to it.

Creating Bindings

// Create a standard bindings container
Bindings bindings = Bindings.builder().standard();

// Simple bind (type is inferred)
bindings.bind("name", "Alice");
bindings.bind("age", 30);

// Typed bind (explicit type)
bindings.bind("score", Integer.class, 95);

// Generic types using TypeReference
bindings.bind("tags", new TypeReference<List<String>>() {}, new ArrayList<>());

Lambda Shorthand

When running rules, you can pass bindings as lambdas. The parameter name becomes the binding name:

// These two are equivalent:

// Explicit
Bindings b = Bindings.builder().standard();
b.bind("name", "Alice");
b.bind("age", 30);
rule.run(b);

// Lambda shorthand
rule.run(name -> "Alice", age -> 30);

Reading Values

// Get value (returns Object)
Object val = bindings.getValue("name");

// Get the Binding object itself
Binding<String> binding = bindings.getBinding("name");
String name = binding.getValue();  // "Alice"

Updating Values

// Update via the Binding object
Binding<Integer> ageBind = bindings.getBinding("age");
ageBind.setValue(31);

// Or directly on the container
bindings.setValue("age", 31);

Checking Bindings

// Does a binding exist?
boolean exists = bindings.contains("name");  // true

// How many bindings?
int count = bindings.size();

// View as a Map
Map<String, Object> map = bindings.asMap();

Scoped Bindings

Scoped bindings create a child scope that inherits from a parent. Changes in the child don't affect the parent:

Bindings scoped = Bindings.builder().scoped();
// Useful for isolating rule execution contexts

Duplicate names: By default, binding the same name twice will throw an exception. Each binding name must be unique within a container.