petrinet runner

runptnet.js

// list of transitions
// places start at index 1, not zero
// doesn't support multiple tokens in same place / 1-safe
net = [
	[1],[2,3],
	[2],[4],
	[3],[5],
	[4,5],[6]
]

let all = xs => xs.reduce((x, acc) => acc && x, true, xs)

function engine (net) {
	// nr of transitions
	let T = net.length / 2
	
	// nr of places (maximum index used in array)
	let P = Math.max.apply(Math, net.flat())
	
	// new empty state
	let marking = new Array(P).fill(0)
	
	// assume place 1 is the initial marking
	marking[0] = 1

	// retrieving a transition
	let transition = i => {
		let idx = ((i - 1) % T) * 2
		let consume = net[idx]
		let produce = net[idx + 1]

		let enabled = () => {
			let haz = consume.map(p => marking[p - 1] > 0)
			return all(haz)
		}

		let fire = () => {
			if (enabled()) {
				for(let p of consume) {
					marking[p - 1] -= 1
				}
				for(let p of produce) {
					marking[p - 1] += 1
				}
			}
		}
		
		return {enabled, fire}
	}

	return {transition, marking, T, P}
}



let showState = (e) => {
	console.log(`marking: ${e.marking.join(' ')}`)
	let s = ''
	for(let t = 1; t <= e.T; t += 1) {
		s = s + `${e.transition(t).enabled() ? '!' : '_'} `
	}
	console.log(`enabled: ${s}\n------------------`)
}

let e = engine(net)

showState(e)
e.transition(1).fire()
showState(e)

// console.log(e.transition(1).enabled())