// Package "engine" provides an extensible interface for users to interfact with
// λ-calculus.
package engine

import (
	"git.maximhutz.com/max/lambda/internal/config"
	"git.maximhutz.com/max/lambda/pkg/emitter"
)

// Engine is an interface for reduction engines.
type Engine interface {
	Run()
	GetResult() string
	On(message string, fn func()) *emitter.Observer
	Emit(message string)
}

// New creates the appropriate engine based on the config.
func New(cfg *config.Config, input interface{}) Engine {
	if cfg.Interpreter == "debruijn" {
		return NewDeBruijnEngine(cfg, input)
	}
	return NewLambdaEngine(cfg, input)
}