package normalorder

import (
	"git.maximhutz.com/max/lambda/pkg/engine"
	"git.maximhutz.com/max/lambda/pkg/lambda"
)

type Engine struct {
	expr lambda.Expression
}

func (e Engine) Get() (lambda.Expression, error) {
	return e.expr, nil
}

func (e Engine) Set(l lambda.Expression) error {
	e.expr = l
	return nil
}

func (e Engine) Step(i int) bool {
	var reduced bool

	for range i {
		e.expr, reduced = ReduceOnce(e.expr)
		if !reduced {
			return false
		}
	}

	return true
}

var _ engine.Engine[lambda.Expression] = (*Engine)(nil)