the documentation doesn't say if I can instantiate those classes, or does it?
if I could understand via GIRepository.Repository if a class could be extended/instantiated I could improve cgjs-about to show that right away. So far I thought that `objects` where all usable as `new Class` but that's not the case at all. Maybe I should check for an `is_abstract_object` ? Not sure there is anything like that though. Thanks. On Wed, Nov 8, 2017 at 3:41 AM, <philip.chime...@gmail.com> wrote: > This comes a bit too late to help you, sorry, but the C docs will tell you > which classes extend a base class, e.g. for GInputStream (Gio.InputStream > in GJS): https://developer.gnome.org/gio/stable/GInputStream. > html#GInputStream.object-hierarchy > > On Tue, Nov 7, 2017 at 2:36 PM Andrea Giammarchi < > andrea.giammar...@gmail.com> wrote: > >> so, just FYI ... >> >> Buffered, Converter, Data, File, Memory and Unix InputStream are >> available. >> >> Buffered, Converter, and Data need a base_stream to work ... not a >> primitive. >> >> File and Unix need attributes or fd pointers >> >> The Memory seems to be the "base/primitive" I was looking for together >> with its MemoryOutputStream counterpart. >> >> Regards >> >> >> >> On Tue, Nov 7, 2017 at 7:28 PM, Andrea Giammarchi < >> andrea.giammar...@gmail.com> wrote: >> >>> oh gosh, my own utility ... that is less useful in pretty print for >>> these kind of things .... although the list has many non-usable streams but >>> now I want to know which one is usable. >>> >>> P.S. for namespaces you don't' need gi prefix ... cgjs-about Gio would >>> do the same ;-) >>> >>> Thanks again >>> >>> On Tue, Nov 7, 2017 at 7:09 PM, Sam Jansen <sam.jan...@starleaf.com> >>> wrote: >>> >>>> >>>> >>>> On 7 November 2017 at 21:55, Andrea Giammarchi < >>>> andrea.giammar...@gmail.com> wrote: >>>> >>>>> this is gold, thank you!!! >>>>> >>>>> do you know if MemoryInputStream is the only one usable? is there any >>>>> list of available GJS streams one can use? I think memory is just fine >>>>> though, thanks again a lot! >>>>> >>>>> >>>> I just took an educated guess: I figured anything useful would extend >>>> Gio.InputStream. I then just browsed through the docs, looking for anything >>>> with "InputStream" in their name, which isn't so many... >>>> >>>> This is a good place to start perhaps: >>>> >>>> $ cgjs-about gi.Gio --json | grep InputStream | grep -Ev "Class|Private" >>>> >>>> >>>> It would be a neat extension to cgjs-about if one could have it list >>>> the classes known to implement an interface or extend from a class... >>>> >>>> >>>>> On Tue, Nov 7, 2017 at 6:46 PM, Sam Jansen <sam.jan...@starleaf.com> >>>>> wrote: >>>>> >>>>>> Hi Andrea, >>>>>> >>>>>> I've come up with something that... almost does what you're looking >>>>>> at here. Perhaps it's useful as a guide of what one can do with the Gio >>>>>> interface. >>>>>> >>>>>> I think you may hit some awkward problems with modelling Node-style >>>>>> streams with GLib ones. But perhaps it is possible and this helps. I >>>>>> don't >>>>>> really know the Node stream semantics so I have assumed various things in >>>>>> my Readable implementation as you'll see... Note that MemoryInputStream >>>>>> really is just a byte stream; so there is no guarantee you'll receive the >>>>>> exact block of bytes that was written -- for example, when I run this I >>>>>> get >>>>>> a first chunk of "12", followed by "3", "4", etc. >>>>>> >>>>>> >>>>>> let Gio = imports.gi.Gio; >>>>>> let byteArray = imports.byteArray; >>>>>> let mainloop = imports.mainloop; >>>>>> >>>>>> class Readable { >>>>>> constructor() { >>>>>> this._mio = Gio.MemoryInputStream.new(); >>>>>> this._callbacks = {}; >>>>>> this._startNext(); >>>>>> } >>>>>> >>>>>> _startNext() { >>>>>> // Enqueue an async read; and re-enqueue when it finishes, so >>>>>> we're >>>>>> // always waiting for data... >>>>>> this._mio.read_bytes_async(4096, 1, null, (source, res) => { >>>>>> this._onData(this._mio.read_bytes_finish(res)); >>>>>> this._startNext(); >>>>>> }); >>>>>> } >>>>>> >>>>>> _onData(bytes) { >>>>>> if (this._callbacks['data']) { >>>>>> let ba = byteArray.fromGBytes(bytes); >>>>>> this._callbacks['data'](ba); >>>>>> this._read(); >>>>>> } >>>>>> } >>>>>> >>>>>> push(bytes) { >>>>>> if (bytes == null) { >>>>>> mainloop.quit('main'); >>>>>> return; >>>>>> } >>>>>> this._mio.add_bytes(bytes); >>>>>> } >>>>>> >>>>>> on(name, callback) { >>>>>> this._callbacks[name] = callback; >>>>>> if (name === 'data') { >>>>>> this._read(); >>>>>> } >>>>>> } >>>>>> } >>>>>> >>>>>> class Counter extends Readable { >>>>>> constructor(opt) { >>>>>> super(opt); >>>>>> this._max = 1000; >>>>>> this._index = 1; >>>>>> } >>>>>> >>>>>> _read() { >>>>>> const i = this._index++; >>>>>> if (i > this._max) >>>>>> this.push(null); >>>>>> else { >>>>>> const str = '' + i; >>>>>> const buf = byteArray.fromString(str); // Buffer.from(str, >>>>>> 'ascii'); >>>>>> this.push(buf); >>>>>> } >>>>>> } >>>>>> } >>>>>> >>>>>> (new Counter).on('data', (str) => { >>>>>> print("data", str.toString()); >>>>>> }); >>>>>> >>>>>> mainloop.run('main'); >>>>>> >>>>>> >>>>>> On 7 November 2017 at 10:08, Andrea Giammarchi < >>>>>> andrea.giammar...@gmail.com> wrote: >>>>>> >>>>>>> I am trying to implement a stream module and apparently I have >>>>>>> everything I need but practically I'm unable to use streams. >>>>>>> >>>>>>> If I instantiate a `new Gio.InputStream` I have the following error: >>>>>>> cannot create instance of abstract (non-instantiatable) type >>>>>>> 'GInputStream' >>>>>>> >>>>>>> I cannot even extend it ... so I've though "ok, maybe it's like an >>>>>>> interface, I implement it and that's it" >>>>>>> >>>>>>> But then a JS class wouldn't work as base_stream for a >>>>>>> Gio.BufferedInputStream, and if I extend the JS class to be a >>>>>>> GObject.Object then: >>>>>>> Gjs-WARNING **: JS ERROR: TypeError: Object is of type >>>>>>> GObject.Object - cannot convert to GInputStream >>>>>>> >>>>>>> where GInputStream is the one I cannot use in the first place. >>>>>>> >>>>>>> I've reached full circle then so ... I wonder if anyone has any idea >>>>>>> how to use/create/extend streams in GJS (not talking about file streams >>>>>>> but >>>>>>> streams in general) or if it's even possible. >>>>>>> >>>>>>> In node, as example, I could do this and it will work: >>>>>>> >>>>>>> ```js >>>>>>> >>>>>>> const { Readable } = require('stream'); >>>>>>> >>>>>>> class Counter extends Readable { >>>>>>> constructor(opt) { >>>>>>> super(opt); >>>>>>> this._max = 1000; >>>>>>> this._index = 1; >>>>>>> } >>>>>>> >>>>>>> _read() { >>>>>>> const i = this._index++; >>>>>>> if (i > this._max) >>>>>>> this.push(null); >>>>>>> else { >>>>>>> const str = '' + i; >>>>>>> const buf = Buffer.from(str, 'ascii'); >>>>>>> this.push(buf); >>>>>>> } >>>>>>> } >>>>>>> } >>>>>>> >>>>>>> (new Counter).on('data', console.log); >>>>>>> >>>>>>> ``` >>>>>>> >>>>>>> _______________________________________________ >>>>>>> javascript-list mailing list >>>>>>> javascript-list@gnome.org >>>>>>> https://mail.gnome.org/mailman/listinfo/javascript-list >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> _______________________________________________ >> javascript-list mailing list >> javascript-list@gnome.org >> https://mail.gnome.org/mailman/listinfo/javascript-list >> >
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