prelude.jang

List.contains = function(e) {
    var i = 0;
    var contained = false;
    while (i < this.length()) {
        if (this[i] == e) {
            return true;
        }
        i += 1
    };
    return false;
};

List.find = function(e) {
    var i = 0;
    while (i < this.length()) {
        if (this[i] == e) {
            return i;
        }
        i += 1;
    };
    return -1;
};

List.any = function(f) {
    var i = 0;
    while (i < this.length()) {
        if (f(this[i])) {
            return true;
        }
        i += 1;
    };
    return false;
};

List.all = function(f) {
    !(this.any(function(e) {!f(e)}))
};

List.forEach = function(f) {
    var i = 0;
    while(i < this.length()) {
        f(this[i])
        i += 1
    }
}

List.map = function(f) {
    var result = []
    this.forEach(function(e) {
        result.append(f(e))
    })
    return result
}

Object.ownItems = function() {
    var that = this;
    return this.items().filter(function(e) {e in that});
}

String.capitalize = function() {
    return this[0].toUpper() + this[1:]
}