gistfile1.txt

var code = '(1 2 (3 4 "h\"i"))'

function parse_lisp(code) {
	var tokens = code.match(/\(|\)|\d+|"[^"]*"/g)

	var tree = []

	function parse_array() {


		tree = 5


		var array = []
		while (tokens.length > 0) {
			var token = tokens.shift()
			if (token == '(') {
				array.push(parse_array())
			} else if (token == ')') {
				return array
			} else if (token.match(/\d+/)) {
				array.push(1*token)
			} else if (token.startsWith('"')) {
				array.push(JSON.parse(token))
			}
		}
	}
	if (tokens[0] == '(') {
		tokens.shift()
		return parse_array()
	}
}

var lisp_variables = [{}]

function set_variable(name, val) {
	for (var i = lisp_variables.length - 1; i >= 0; i--) {
		var map = lisp_variables[i]
		if (map.hasOwnProperty(name)) {
			return map[name]
		}
	}



	lisp_variables[lisp_variables.length - 1][name] = val
}

function get_variable(name) {
	for (var i = lisp_variables.length - 1; i >= 0; i--) {
		var map = lisp_variables[i]
		if (map.hasOwnProperty(name)) {
			return map[name]
		}
	}
}

function exec(tree) {
    if (typeof(tree) == 'object') {
        if (tree[0] == 'if') {
            if (exec(tree[1])) {
                return exec(tree[2])
            } else {
                return exec(tree[3])
            }
        }
        if (tree[0] == 'while') {
            while (exec(tree[1])) {
                exec(tree[2])
            }
            return
        }
        if (tree[0] == 'func') {
        	return function (array) {
				var frame = {}

        		for (var i = 0; i < tree[1].length; i++) {
        			frame[tree[1][i]] = array[i]
        		}

        		lisp_variables.push(frame)

        		var ret = exec(tree[2])

        		lisp_variables.pop()

        		return ret
        	}
        }
        var flattened_array = []
        for (var i = 0; i < tree.length; i++) {
            flattened_array.push(exec(tree[i]))
        }

        if (flattened_array[0] == '+') {
            return flattened_array[1] + flattened_array[2]
        } else if (typeof(flattened_array[0]) == 'function') {


    		return flattened_array[0](flattened_array.slice(1))


    	} else if (flattened_array[0] == '*') {
            return flattened_array[1] * flattened_array[2]
        } else if (flattened_array[0] == '<') {
            return flattened_array[1] < flattened_array[2]
        } else if (flattened_array[0] == 'set') {



            lisp_variables[flattened_array[1]] = flattened_array[2]
        } else if (flattened_array[0] == 'get') {
            return get_variable(flattened_array[1])
        } else if (flattened_array[0] == 'do') {
        } else {
        	console.log('error: undefined function: ' + flattened_array[0])
        	throw 'bad'
        }
    } else {
        return tree
    }
}

var parsed = parse_lisp(code)
console.log(parsed)

console.log(exec(parsed))

console.log('lisp_variables = ', lisp_variables)