import hash_map
import vec
import io
import serialize
import set

fun hash_set<T>(): hash_set<T> {
    var toRet.construct() : hash_set<T>
    return toRet
}

fun hash_set<T>(item: T): hash_set<T> {
    var toRet.construct() : hash_set<T>
    toRet.add(item)
    return toRet
}

fun from_vector<T>(items: vec::vec<T>): hash_set<T> {
    var toRet.construct() : hash_set<T>
    items.for_each( fun(item: T) toRet.add(item); )
    return toRet
}

obj hash_set<T> (Object, Serializable) {
    var data: hash_map::hash_map<T,bool>
    fun construct(): *hash_set<T> {
        data.construct()
        return this
    }
    /*fun construct(ammt: int): *hash_set<T> {*/
        /*data.construct(ammt)*/
        /*return this*/
    /*}*/
    fun copy_construct(old: *hash_set<T>) {
        data.copy_construct(&old->data)
    }
    fun operator=(rhs: ref hash_set<T>) {
        data = rhs.data
    }
    fun serialize(): vec::vec<char> {
        return serialize::serialize(data)
    }
    fun unserialize(it: ref vec::vec<char>, pos: int): int {
        return data.unserialize(it, pos)
    }
    // the old unnecessary template to prevent generation
    // if not used trick (in this case, changing out U with V)
    fun operator==<V>(other: ref hash_set<V>): bool {
        return data == other.data
    }
    fun operator!=(rhs: ref hash_set<T>): bool {
        return ! (*this == rhs)
    }
    fun destruct() {
        data.destruct()
    }
    fun size():int {
        return data.size
    }
    /*fun contains(items: ref hash_set<T>): bool {*/
        /*return items.size() == 0 || !items.any_true( fun(item: T): bool return !contains(item); )*/
    /*}*/
    fun contains(item: ref T): bool {
        return data.contains_key(item)
    }
    fun operator+=(item: ref T) {
        add(item)
    }
    /*fun operator+=(items: ref hash_set<T>) {*/
        /*add(items)*/
    /*}*/
    /*fun operator+(items: ref hash_set<T>): hash_set<T> {*/
        /*var to_ret.copy_construct(this): hash_set<T>*/
        /*to_ret.add(items)*/
        /*return to_ret*/
    /*}*/
    fun add(item: ref T) {
        if (!contains(item))
            data.set(item,true)
    }
    /*fun add_all(items: ref hash_set<T>) {*/
        /*add(items)*/
    /*}*/
    /*fun add(items: ref hash_set<T>) {*/
        /*items.for_each( fun(item: ref T) add(item); )*/
    /*}*/
    fun remove(item: ref T) {
        data.remove(item)
    }
    /*fun for_each(func: fun(ref T):void) {*/
        /*data.for_each(func)*/
    /*}*/
    fun for_each(func: fun(T):void) {
        data.for_each(fun(key: T, value: bool) { func(key); })
    }
    fun map<U>(func: fun(T):U): set::set<U> {
        var newSet.construct(size()): set::set<U>
        for_each(fun(i: T) { newSet.add(func(i)); })
        return newSet
    }
    /*fun any_true(func: fun(T):bool):bool {*/
        /*return data.any_true(func)*/
    /*}*/
    /*fun reduce<U>(func: fun(T,U): U, initial: U): U {*/
        /*return data.reduce(func, initial)*/
    /*}*/
    /*fun flatten_map<U>(func: fun(T):hash_set<U>):hash_set<U> {*/
        /*var newSet.construct(size()): hash_set<U>*/
        /*for (var i = 0; i < size(); i++;)*/
            /*func(data[i]).for_each(fun(item: ref U) newSet.add(item);)*/
        /*return newSet*/
    /*}*/
    /*fun filter(func: fun(T):bool):hash_set<T> {*/
        /*var newSet.construct(): hash_set<T>*/
        /*newSet.data = data.filter(func)*/
        /*return newSet*/
    /*}*/
    fun chaotic_closure(func: fun(T): set::set<T>) {
        var prev_size = 0
        while (prev_size != size()) {
            prev_size = size()
            var to_add.construct(size()): vec::vec<T>
            for_each(fun(i: T) {
                func(i).for_each(fun(j: T) { to_add.add(j); })
            })
            to_add.for_each(fun(i:T) { add(i); })
        }

    }
    fun pop(): T {
        return data.pop().first
    }
    fun union(other: hash_set<T>): hash_set<T> {
        for_each(fun(i: T) {
            other.add(i)
        })
        return other
    }
    fun operator-(items: ref hash_set<T>): hash_set<T> {
        var to_ret.copy_construct(this): hash_set<T>
        items.for_each(fun(i: T) {
            to_ret.remove(i)
        })
        return to_ret
    }
}