file.js

/**
 * @constructor
 * @param {Sk.builtin.str} name
 * @param {Sk.builtin.str} mode
 * @param {Object} buffering
 */
Sk.builtin.file = function (name, mode, buffering) {
    var i;
    var elem;
    this.mode = mode;
    this.name = name;
    this.closed = false;
    if (Sk.inBrowser) {  // todo:  Maybe provide a replaceable function for non-import files
        elem = document.getElementById(name.v);
        if (elem == null) {
            throw new Sk.builtin.IOError("[Errno 2] No such file or directory: '" + name.v + "'");
        } else {
            if (elem.nodeName.toLowerCase() == "textarea") {
                this.data$ = elem.value;
            }
            else {
                this.data$ = elem.textContent;
            }
        }
    } else {
        this.data$ = Sk.read(name.v);
    }
    this.lineList = this.data$.split("\n");
    this.lineList = this.lineList.slice(0, -1);
    for (i in this.lineList) {
        this.lineList[i] = this.lineList[i] + "\n";
    }
    this.currentLine = 0;
    this.pos$ = 0;

    this.__class__ = Sk.builtin.file;

    return this;
};

Sk.builtin.file.prototype.ob$type = Sk.builtin.type.makeIntoTypeObj("file", Sk.builtin.file);

Sk.builtin.file.prototype.tp$getattr = Sk.builtin.object.prototype.GenericGetAttr;

Sk.builtin.file.prototype["$r"] = function () {
    return new Sk.builtin.str("<" +
        (this.closed ? "closed" : "open") +
        "file '" +
        this.name +
        "', mode '" +
        this.mode +
        "'>");
};

Sk.builtin.file.prototype.tp$iter = function () {
    var allLines = this.lineList;

    var ret =
    {
        tp$iter    : function () {
            return ret;
        },
        $obj       : this,
        $index     : 0,
        $lines     : allLines,
        tp$iternext: function () {
            if (ret.$index >= ret.$lines.length) {
                return undefined;
            }
            return new Sk.builtin.str(ret.$lines[ret.$index++]);
        }
    };
    return ret;
};


Sk.builtin.file.prototype["close"] = new Sk.builtin.func(function (self) {
    self.closed = true;
});


Sk.builtin.file.prototype["flush"] = new Sk.builtin.func(function (self) {
});
Sk.builtin.file.prototype["fileno"] = new Sk.builtin.func(function (self) {
    return 10;
}); // > 0, not 1/2/3
Sk.builtin.file.prototype["isatty"] = new Sk.builtin.func(function (self) {
    return false;
});


Sk.builtin.file.prototype["read"] = new Sk.builtin.func(function (self, size) {
    var ret;
    var len;
    if (self.closed) {
        throw new Sk.builtin.ValueError("I/O operation on closed file");
    }
    len = self.data$.length;
    if (size === undefined) {
        size = len;
    }
    ret = new Sk.builtin.str(self.data$.substr(self.pos$, size));
    self.pos$ += size;
    if (self.pos$ >= len) {
        self.pos$ = len;
    }
    return ret;
});

Sk.builtin.file.prototype["readline"] = new Sk.builtin.func(function (self, size) {
    var line = "";
    if (self.currentLine < self.lineList.length) {
        line = self.lineList[self.currentLine];
        self.currentLine++;
    }
    return new Sk.builtin.str(line);
});

Sk.builtin.file.prototype["readlines"] = new Sk.builtin.func(function (self, sizehint) {
    var i;
    var arr = [];
    for (i = self.currentLine; i < self.lineList.length; i++) {
        arr.push(new Sk.builtin.str(self.lineList[i]));
    }
    return new Sk.builtin.list(arr);
});

Sk.builtin.file.prototype["seek"] = new Sk.builtin.func(function (self, offset, whence) {
    if (whence === undefined) {
        whence = 1;
    }
    if (whence == 1) {
        self.pos$ = offset;
    } else {
        self.pos$ = self.data$ + offset;
    }
});

Sk.builtin.file.prototype["tell"] = new Sk.builtin.func(function (self) {
    return self.pos$;
});


Sk.builtin.file.prototype["truncate"] = new Sk.builtin.func(function (self, size) {
    goog.asserts.fail();
});

Sk.builtin.file.prototype["write"] = new Sk.builtin.func(function (self, str) {
    goog.asserts.fail();
});


goog.exportSymbol("Sk.builtin.file", Sk.builtin.file);