OS.File will provide JS file read/write using ArrayBuffer. I believe that, atm, we have no way of converting between an ArrayBuffer and a string, which is a shame. Note that this is very related to bug 552551.

There was some discussion of such a thing on the whatwg list, IIRC.

Converting in what sense? One jschar per byte, via byte inflation? Or something else?

(In reply to David Rajchenbach Teller [:Yoric] from comment #0) > OS.File will provide JS file read/write using ArrayBuffer. I believe that, > atm, we have no way of converting between an ArrayBuffer and a string, which > is a shame. > > Note that this is very related to bug 552551. Couldn't one write JS functions to perform various conversions from ArrayBuffer to string?

new FileReader(new Blob([someArrayBuffer])).readAsWhateverYouWant() will provide various conversions. Is a C++ API really required?

(In reply to Masatoshi Kimura [:emk] from comment #4) > new FileReader(new Blob([someArrayBuffer])).readAsWhateverYouWant() will > provide various conversions. Is a C++ API really required? Good point, this lets us convert an ArrayBuffer to various encodings, which solves a big part of the reading issue - although this might be insufficient if one wishes to decode streams in JavaScript, as we also need to be able to handle cases in which only a prefix of the ArrayBuffer is correctly encoded. Now, how do we do the opposite? Say I have a String and I want to produce an ArrayBuffer with an encoded version of that string.

(In reply to David Rajchenbach Teller [:Yoric] from comment #5) > Good point, this lets us convert an ArrayBuffer to various encodings, which > solves a big part of the reading issue - although this might be insufficient > if one wishes to decode streams in JavaScript, as we also need to be able to > handle cases in which only a prefix of the ArrayBuffer is correctly encoded. Use new Blob([someArrayBuffer]).slice(start, end) or new Blob([new Uint8Array(someArrayBuffer, offset, length)]) (Fx15+) > Now, how do we do the opposite? Say I have a String and I want to produce an > ArrayBuffer with an encoded version of that string. Unfortunately existing APIs are intentionally crippled to promote UTF-8 :( So some APIs will be needed to encode a string back to an ArrayBuffer with a non-UTF-8 encoding.

(In reply to Masatoshi Kimura [:emk] from comment #6) > (In reply to David Rajchenbach Teller [:Yoric] from comment #5) > > Good point, this lets us convert an ArrayBuffer to various encodings, which > > solves a big part of the reading issue - although this might be insufficient > > if one wishes to decode streams in JavaScript, as we also need to be able to > > handle cases in which only a prefix of the ArrayBuffer is correctly encoded. > Use > new Blob([someArrayBuffer]).slice(start, end) > or > new Blob([new Uint8Array(someArrayBuffer, offset, length)]) (Fx15+) That's assuming you know how many bytes form a proper well-encoded string. In the case of a stream, you typically receive |n| bytes (with |n| fixed), but only a prefix of unknown length is actually a well-encoded string. In a multi-byte encoding, the final few bytes are often an incomplete char, which needs special handling. > > > Now, how do we do the opposite? Say I have a String and I want to produce an > > ArrayBuffer with an encoded version of that string. > Unfortunately existing APIs are intentionally crippled to promote UTF-8 :( > So some APIs will be needed to encode a string back to an ArrayBuffer with a > non-UTF-8 encoding. In that case, I am keeping this bug open :)

StringEncoding API (bug 764234) would meet the requirements. It supports streaming encoding/decoding. If you need to convert a non-UTF8 ArrayBuffer to a string, I consider adding a Chrome-only option to TextEncoder so that it can encode non-UTF8 bytes.

> non-UTF8 ArrayBuffer non-UTF ArrayBuffer. TextEncoder supports utf-8, utf-16, and utf-16be atm.

> convert a non-UTF8 ArrayBuffer to a string It was "convert a string to a non-UTF ArrayBuffer"... TextDecoder (ArrayBuffer-to-string converter) accepts non-UTF encodings.

Is there anything left here to do?

I think we're ok.