be5invis/jsbin.pecapusa.html

## jsbin.pecapusa.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JS Bin</title>
</head>
<body>

</body>
</html>

## jsbin.pecapusa.js
var Ref = function(s){ this.ref = s }
var newt = function(n){
	return function(){
		return new Ref("_" + (n++))
	}
}(0);

function id(x){ return x }
function normalizeTerm(form){ return normalize(form, id) }
function normalize(form, ctx){
	if(form instanceof Array){
		if(form[0] === '.lambda') return ctx([':LAMBDA', form[1], normalizeTerm(form[2])])
		else if(form[0] === '.yield') {
			var t = newt();
			return normalize(form[1], function(n){
				return [n, [':LAMBDA', [t], ctx(t)]]
			})
		} else if(form[0] === '=') {
			return normalizeAssign(form, ctx)
		} else return normalizeCall(form, ctx)
	} else if(typeof form === 'string') {
		return ctx([':GETV', form])
	}
}
function normalizeArg(form, ctx){
	return normalize(form, function(n){
		var t = newt();
		return [':LET', t, n, ctx(t)]
	})
}
function normalizeAssign(form, ctx){
	if(form[1] && form[1][0] === '.'){
		return normalize(form[1][1], function(tl){
			return normalize(form[1][2], function(tr){
				return normalize(form[2], function(n){
					return normalize(form[2], function(n){
						var t = newt();
						return [':LET', t, ['=', ['.', tl, tr], n], ctx(t)]
					})
				})
			})
		})
	} else {
		return normalize(form[2], function(n){
			var t = newt();
			return [':LET', t, ['=', form[1], n], ctx(t)]
		})
	}
}
function normalizeCall(form, ctx){
	if(form[0] && form[0][0] === '.'){
		return normalizeArg(form[0][1], function(tl){
			return normalizeArg(form[0][2], function(tr){
				return normalizeList(form.slice(1), function(t$){
					if(t$) return ctx([['.', tl, tr].concat(t$)])
					else return ctx([['.', tl, tr]])
				})
			})
		})
	} else {
		return normalizeList(form, ctx);
	}
}
function normalizeList(form, ctx){
	if(!form.length){
		return ctx(null)
	} else {
		return normalizeArg(form[0], function(t){
			return normalizeList(form.slice(1), function(t$){
				if(t$) return ctx([t].concat(t$));
				else return ctx([t])
			})
		})
	}
};

function redex(form){
	if(form instanceof Ref){
		var r = {};
		r[form.ref] = true;
		return {value: form, refes: r}
	} else if(form instanceof Array){
		if(form[0] === ':LET'){ // Let bind
			var body = redex(form[3]);
			var bound = redex(form[2]);
			if(body.refes[form[1].ref]) {
				form[1].ref = bound.value;
				for(var each in bound.refes) body.refes[each] = true;
				return body
			} else {
				var r = {};
				for(var each in bound.refes) r[each] = true;
				for(var each in body.refes) r[each] = true;
				return {value: ['!LET', form[1], bound.value, body.value], refes: r}
			}
		} else if(form[0] === ':LAMBDA'){
			return {value: ['!LAMBDA', form[1], redex(form[2]).value], refes: {}}
		} else if(form[0] === ':GETV'){
			return {value: ['!GETV', form[1]], refes: {}}
		} else {
			var a = [], r = {};
			for(var j = 0; j < form.length; j++){
				var term = redex(form[j]);
				a[j] = term.value;
				for(var each in term.refes) r[each] = true;
			};
			return {value: a, refes: r}
		}
	} else {
		return {value: form, refes: {}}
	}
}
function shrink(form){
	if(form instanceof Ref){
		return shrink(form.ref)
	} else if(form instanceof Array){
		return form.map(shrink)
	} else {
		return form
	}
}

console.log(shrink(redex(normalizeTerm(['begin', ['=', ['.', ['.yield', 'o'], 'm'], 'x']])).value));
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>JS Bin</title>
	</head>
	<body>

	</body>
	</html>
	var Ref = function(s){ this.ref = s }
	var newt = function(n){
	return function(){
	return new Ref("_" + (n++))
	}
	}(0);

	function id(x){ return x }
	function normalizeTerm(form){ return normalize(form, id) }
	function normalize(form, ctx){
	if(form instanceof Array){
	if(form[0] === '.lambda') return ctx([':LAMBDA', form[1], normalizeTerm(form[2])])
	else if(form[0] === '.yield') {
	var t = newt();
	return normalize(form[1], function(n){
	return [n, [':LAMBDA', [t], ctx(t)]]
	})
	} else if(form[0] === '=') {
	return normalizeAssign(form, ctx)
	} else return normalizeCall(form, ctx)
	} else if(typeof form === 'string') {
	return ctx([':GETV', form])
	}
	}
	function normalizeArg(form, ctx){
	return normalize(form, function(n){
	var t = newt();
	return [':LET', t, n, ctx(t)]
	})
	}
	function normalizeAssign(form, ctx){
	if(form[1] && form[1][0] === '.'){
	return normalize(form[1][1], function(tl){
	return normalize(form[1][2], function(tr){
	return normalize(form[2], function(n){
	return normalize(form[2], function(n){
	var t = newt();
	return [':LET', t, ['=', ['.', tl, tr], n], ctx(t)]
	})
	})
	})
	})
	} else {
	return normalize(form[2], function(n){
	var t = newt();
	return [':LET', t, ['=', form[1], n], ctx(t)]
	})
	}
	}
	function normalizeCall(form, ctx){
	if(form[0] && form[0][0] === '.'){
	return normalizeArg(form[0][1], function(tl){
	return normalizeArg(form[0][2], function(tr){
	return normalizeList(form.slice(1), function(t$){
	if(t$) return ctx([['.', tl, tr].concat(t$)])
	else return ctx([['.', tl, tr]])
	})
	})
	})
	} else {
	return normalizeList(form, ctx);
	}
	}
	function normalizeList(form, ctx){
	if(!form.length){
	return ctx(null)
	} else {
	return normalizeArg(form[0], function(t){
	return normalizeList(form.slice(1), function(t$){
	if(t$) return ctx([t].concat(t$));
	else return ctx([t])
	})
	})
	}
	};

	function redex(form){
	if(form instanceof Ref){
	var r = {};
	r[form.ref] = true;
	return {value: form, refes: r}
	} else if(form instanceof Array){
	if(form[0] === ':LET'){ // Let bind
	var body = redex(form[3]);
	var bound = redex(form[2]);
	if(body.refes[form[1].ref]) {
	form[1].ref = bound.value;
	for(var each in bound.refes) body.refes[each] = true;
	return body
	} else {
	var r = {};
	for(var each in bound.refes) r[each] = true;
	for(var each in body.refes) r[each] = true;
	return {value: ['!LET', form[1], bound.value, body.value], refes: r}
	}
	} else if(form[0] === ':LAMBDA'){
	return {value: ['!LAMBDA', form[1], redex(form[2]).value], refes: {}}
	} else if(form[0] === ':GETV'){
	return {value: ['!GETV', form[1]], refes: {}}
	} else {
	var a = [], r = {};
	for(var j = 0; j < form.length; j++){
	var term = redex(form[j]);
	a[j] = term.value;
	for(var each in term.refes) r[each] = true;
	};
	return {value: a, refes: r}
	}
	} else {
	return {value: form, refes: {}}
	}
	}
	function shrink(form){
	if(form instanceof Ref){
	return shrink(form.ref)
	} else if(form instanceof Array){
	return form.map(shrink)
	} else {
	return form
	}
	}

	console.log(shrink(redex(normalizeTerm(['begin', ['=', ['.', ['.yield', 'o'], 'm'], 'x']])).value));