Re: Deploying Vibe.d applications to OpenShift
Please let me know how you did it, because I know it's possible with the DIY-cartridge they provide you(atleast it should be). I tried it some time ago. It is possible but: - vibe.d requires a lot of memory for project compilation - it is hard to install additional libraries (it is not usual Linux distrib)
Type deduction on templated constructor.
So, I have this code (also on http://dpaste.dzfl.pl/3f767b17e83c)
This Vector(T) struct is taken from gfm.math.vector.
struct Vector(T) {
T x, y, z;
this(X : T, Y : T, Z : T)(X x_, Y y_, Z z_)
{
x = x_; y = y_; z = z_;
}
}
void main()
{
Vector!ubyte test = Vector!ubyte(1, 1, 1);
}
It fails to compile because template
f508.Vector!ubyte.Vector.__ctor cannot deduce function from
argument types !()(int, int, int).
Note that if one just defines a constructor as this(T x_, T y_, T
z_) everything works.
My question is: should this code compile? I understand that the
literal 1 is int therefore it can screw type deduction, but I
wonder if the compiler should be smart enough to deduce it
correctly.
Re: Type deduction on templated constructor.
francesco cattoglio: should this code compile? I understand that the literal 1 is int therefore it can screw type deduction, but I wonder if the compiler should be smart enough to deduce it correctly. To keep both the compiler and programmers sane, D templates don't perform implicit type conversions. This sometimes is not handy, but on the whole saves from a large number of troubles. So you can write (D V.2.066): Vector!ubyte(ubyte(1), ubyte(1), ubyte(1)); Or you can create a little helper function that makes that code more DRY. Bye, bearophile
Re: Type deduction on templated constructor.
On Thursday, 24 July 2014 at 09:38:14 UTC, bearophile wrote: francesco cattoglio: should this code compile? I understand that the literal 1 is int therefore it can screw type deduction, but I wonder if the compiler should be smart enough to deduce it correctly. To keep both the compiler and programmers sane, D templates don't perform implicit type conversions. This sometimes is not handy, but on the whole saves from a large number of troubles. So you can write (D V.2.066): Vector!ubyte(ubyte(1), ubyte(1), ubyte(1)); Or you can create a little helper function that makes that code more DRY. Bye, bearophile I expected such an answer and I do understand the decisions behind it. Yet, you gave me a really GOOD news! Having to write cast(ubyte) 1 was way too much verbose for my liking, while the new ubyte(1) is reasonable enough.
Re: How to know whether a file's encoding is ansi or utf8?
I first try to load the file as utf8 (or some 8kb at the start of it) with encoding exceptions turned on, if I catch an exception, I reload it as ansi, otherwise I assume it's valid utf8.
Re: Deploying Vibe.d applications to OpenShift
On 2014-07-24 3:45 AM, Nikolay wrote: Please let me know how you did it, because I know it's possible with the DIY-cartridge they provide you(atleast it should be). I tried it some time ago. It is possible but: - vibe.d requires a lot of memory for project compilation - it is hard to install additional libraries (it is not usual Linux distrib) You should compile and test on a CentOS 6.3 machine first and then write the cartridge using the wget command to move the same libevent package and the compiled vibe.d binary. You won't be able to compile on a cartridge. Your cartridge would look like this: https://github.com/Filirom1/openshift-cartridge-nodejs/blob/master/bin/setup
Re: Deploying Vibe.d applications to OpenShift
On Thursday, 24 July 2014 at 02:48:45 UTC, Rutger wrote: On Thursday, 24 July 2014 at 01:47:43 UTC, Rikki Cattermole wrote: On 24/07/2014 1:28 p.m., Rutger wrote: Hello! Really enjoying D so far and have started to toy around with Vibe.d. I was just wondering if someone here has had any experience with publishing vibe applications on the OpenShift Paas? (https://www.openshift.com) Please let me know how you did it, because I know it's possible with the DIY-cartridge they provide you(atleast it should be). I was looking into it a while back. Its not so much the cartridges which are a problem. They are pretty easy to make. The issue is with the gears. 2gb is the max and most expensive. But with D unless your very careful 1gb is more the norm. Atleast in my tests with Cmsed. Also you will need to find a way to compile for their instances OS. Could be an issue as its most likely redhat (as its owned by them). But they have a free plan. Might as well have a go. Right now I've managed to try and start the binary but it logs an error because the required libraries can't be found. Also do you know if it's possible to compile a binary on ubuntu that will be compatible with RHEL/Fedora? Yes. However, you will probably have compatibility problems with the various shared libraries loaded by your executable, most prominently glibc.
zlibs gzip dosent work with http
I'm trying to add gzip compression to a HTTP server i wrote in D.
here is the code that dose the gzip encoding.
if ((Info.modGzip)
(indexOf(client.getRequestHeaderFieldValue(Accept-Encoding),gzip)
!= -1)){
writeln(gzip);
auto gzip = new Compress(HeaderFormat.gzip);
client.addToResponseHeader(Content-Encoding: gzip);
client.sendHeader(200 ok);
while (0 (filestream.readBlock(readbuffer))){
client.client.send(gzip.compress(readbuffer));
}
client.client.send(gzip.flush());
delete gzip;
delete filestream;
}
but when i test it Firefox, internet explorer and chrome says
that the encoding or compression is bad. why? the data is
compressed with gzip.
the rest of the code is available at
http://sourceforge.net/p/netspark/netsparkb1/ci/master/tree/
Git
git clone git://git.code.sf.net/p/netspark/netsparkb1
netspark-netsparkb1
Segfault games with factorials
I have the following code in fac.d (modified from the factorial
examples on RosettaCode):
#!/usr/bin/rdmd
import std.bigint;
pure BigInt factorial(BigInt n) {
static pure BigInt inner(BigInt n, BigInt acc) {
return n == 0 ? acc : inner(n - 1, acc * n);
}
return inner(n, BigInt(1));
}
void main(string[] args) {
import std.stdio;
BigInt input = args[1];
writeln(factorial(input));
return;
}
It (more or less consistently) on my machine will calculate 'fac
47610', and (more or less consistently) will core dump with a
segfault on 'fac 47611'.
Interestingly, if I redirect stdout to a file it will usually
manage to get to 47612.
To satisfy my own curiosity about what's happening, are there any
resources I can use to analyse the core dump?
Thanks.
Re: zlibs gzip dosent work with http
On Thursday, 24 July 2014 at 13:09:53 UTC, Sean Campbell wrote:
I'm trying to add gzip compression to a HTTP server i wrote in
D. here is the code that dose the gzip encoding.
I know zlib gzip works for http, I used it in my cgi.d
if(gzipResponse acceptsGzip isAll) {
auto c = new Compress(HeaderFormat.gzip);
// want gzip
auto data = c.compress(t);
data ~= c.flush();
t = data;
}
But your http server is buggy in a lot of ways. It doesn't reply
to curl and doesn't keep the connection open to issue manual
requests.
Among the bugs I see looking at it quickly:
server.d getRequestHeaderFieldValue, you don't check if epos is
-1. If it is, you should return null or something instead of
trying to use it - the connection will hang because of an
out-of-bounds array read killing the handler.
You also wrote:
if ((Info.modGzip)
(indexOf(client.getRequestHeaderFieldValue(Accept-Encoding),gzip)
!= -1)){
Notice the instead of . That's in fspipedserver.d.
Finally, you write client.client.send... which never sent the
headers back to the client, so it didn't know you were gzipping!
Change that to client.sendData (and change sendData in server.d
to take in void[] instead of void[]) and then it sends the
headers and seems to work by my eyeballing.
if ((Info.modGzip)
(indexOf(client.getRequestHeaderFieldValue(Accept-Encoding),gzip)
!= -1)){
writeln(gzip);
auto gzip = new Compress(HeaderFormat.gzip);
client.addToResponseHeader(Content-Encoding: gzip);
client.sendHeader(200 ok);
while (0 (filestream.readBlock(readbuffer))){
client.client.send(gzip.compress(readbuffer));
}
client.client.send(gzip.flush());
delete gzip;
delete filestream;
}
but when i test it Firefox, internet explorer and chrome says
that the encoding or compression is bad. why? the data is
compressed with gzip.
the rest of the code is available at
http://sourceforge.net/p/netspark/netsparkb1/ci/master/tree/
Git
git clone git://git.code.sf.net/p/netspark/netsparkb1
netspark-netsparkb1
Re: Segfault games with factorials
On Thu, Jul 24, 2014 at 01:14:40PM +, Darren via Digitalmars-d-learn wrote:
I have the following code in fac.d (modified from the factorial
examples on RosettaCode):
#!/usr/bin/rdmd
import std.bigint;
pure BigInt factorial(BigInt n) {
static pure BigInt inner(BigInt n, BigInt acc) {
return n == 0 ? acc : inner(n - 1, acc * n);
}
return inner(n, BigInt(1));
}
void main(string[] args) {
import std.stdio;
BigInt input = args[1];
writeln(factorial(input));
return;
}
It (more or less consistently) on my machine will calculate 'fac
47610', and (more or less consistently) will core dump with a segfault
on 'fac 47611'.
[...]
You're probably running out of stack space because of your recursive
function. Write it as a loop instead, and you should be able to go
farther:
pure BigInt factorial(BigInt n) {
auto result = BigInt(1);
while (n 1)
result *= n;
return result;
}
T
--
Ignorance is bliss... until you suffer the consequences!
Re: Segfault games with factorials
On Thursday, 24 July 2014 at 14:39:12 UTC, H. S. Teoh via
Digitalmars-d-learn wrote:
On Thu, Jul 24, 2014 at 01:14:40PM +, Darren via
Digitalmars-d-learn wrote:
I have the following code in fac.d (modified from the factorial
examples on RosettaCode):
#!/usr/bin/rdmd
import std.bigint;
pure BigInt factorial(BigInt n) {
static pure BigInt inner(BigInt n, BigInt acc) {
return n == 0 ? acc : inner(n - 1, acc * n);
}
return inner(n, BigInt(1));
}
void main(string[] args) {
import std.stdio;
BigInt input = args[1];
writeln(factorial(input));
return;
}
It (more or less consistently) on my machine will calculate
'fac
47610', and (more or less consistently) will core dump with a
segfault
on 'fac 47611'.
[...]
You're probably running out of stack space because of your
recursive
function. Write it as a loop instead, and you should be able to
go
farther:
pure BigInt factorial(BigInt n) {
auto result = BigInt(1);
while (n 1)
result *= n;
return result;
}
T
It does seem that's the case. Which is odd, as I thought that DMD
and LDC did TCO. Not in this case obviously.
PS. This was a slightly silly program, but in the general case,
is there a way to use a core dump to diagnose a stack overflow?
Re: Segfault games with factorials
On Thursday, 24 July 2014 at 14:59:16 UTC, Darren wrote:
On Thursday, 24 July 2014 at 14:39:12 UTC, H. S. Teoh via
Digitalmars-d-learn wrote:
On Thu, Jul 24, 2014 at 01:14:40PM +, Darren via
Digitalmars-d-learn wrote:
I have the following code in fac.d (modified from the
factorial
examples on RosettaCode):
#!/usr/bin/rdmd
import std.bigint;
pure BigInt factorial(BigInt n) {
static pure BigInt inner(BigInt n, BigInt acc) {
return n == 0 ? acc : inner(n - 1, acc * n);
}
return inner(n, BigInt(1));
}
void main(string[] args) {
import std.stdio;
BigInt input = args[1];
writeln(factorial(input));
return;
}
It (more or less consistently) on my machine will calculate
'fac
47610', and (more or less consistently) will core dump with a
segfault
on 'fac 47611'.
[...]
You're probably running out of stack space because of your
recursive
function. Write it as a loop instead, and you should be able
to go
farther:
pure BigInt factorial(BigInt n) {
auto result = BigInt(1);
while (n 1)
result *= n;
return result;
}
T
It does seem that's the case. Which is odd, as I thought that
DMD and LDC did TCO. Not in this case obviously.
PS. This was a slightly silly program, but in the general case,
is there a way to use a core dump to diagnose a stack overflow?
A debugger should be able to tell you why the segfault occurred.
Re: D JSON (WAT?!)
On Thu, 24 Jul 2014 15:15:36 +, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
That's because it produces a segmentation fault, which rdmd masks for
some reason. The `parsed[fail]` should throw a range bounds exception--
not sure why it's not.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote: string s = parsed[fail].str; Since there is no entry fail in the object, it returns a null JSON_VALUE pointer. Trying to get the string out of it is then seen as a null pointer access and kills the program. Check for null on a key before trying to get a value out.
D JSON (WAT?!)
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
Re: D JSON (WAT?!)
Adam D. Ruppe: Check for null on a key before trying to get a value out. Is something like the get() function usable here? Bye, bearophile
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:22:46 UTC, Adam D. Ruppe wrote: On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote: string s = parsed[fail].str; Since there is no entry fail in the object, it returns a null JSON_VALUE pointer. Trying to get the string out of it is then seen as a null pointer access and kills the program. Check for null on a key before trying to get a value out. Ok, added: writeln(parsed[fail] == null); Now compiler complains: Error: incompatible types for ((parsed.opIndex(fail)) == (null)): 'JSONValue' and 'typeof(null)' WAT?!
Re: D JSON (WAT?!)
Am 24.07.2014 17:29, schrieb Pavel: On Thursday, 24 July 2014 at 15:22:46 UTC, Adam D. Ruppe wrote: On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote: string s = parsed[fail].str; Since there is no entry fail in the object, it returns a null JSON_VALUE pointer. Trying to get the string out of it is then seen as a null pointer access and kills the program. Check for null on a key before trying to get a value out. Ok, added: writeln(parsed[fail] == null); Now compiler complains: Error: incompatible types for ((parsed.opIndex(fail)) == (null)): 'JSONValue' and 'typeof(null)' WAT?! is instead of == ?
Re: D JSON (WAT?!)
On 07/24/2014 08:29 AM, Pavel wrote: writeln(parsed[fail] == null); Now compiler complains: Error: incompatible types for ((parsed.opIndex(fail)) == (null)): 'JSONValue' and 'typeof(null)' WAT?! Comparing against null should be done with the 'is' operator, not the == operator: if (x is null) Ali
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no output
at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend
using http://vibed.org/api/vibe.data.json/ instead
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:31:30 UTC, Daniel Gibson wrote: Am 24.07.2014 17:29, schrieb Pavel: On Thursday, 24 July 2014 at 15:22:46 UTC, Adam D. Ruppe wrote: On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote: string s = parsed[fail].str; Since there is no entry fail in the object, it returns a null JSON_VALUE pointer. Trying to get the string out of it is then seen as a null pointer access and kills the program. Check for null on a key before trying to get a value out. Ok, added: writeln(parsed[fail] == null); Now compiler complains: Error: incompatible types for ((parsed.opIndex(fail)) == (null)): 'JSONValue' and 'typeof(null)' WAT?! is instead of == ? Nope, the compiler still complains.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:20:58 UTC, Justin Whear wrote:
On Thu, 24 Jul 2014 15:15:36 +, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
That's because it produces a segmentation fault, which rdmd
masks for
some reason. The `parsed[fail]` should throw a range bounds
exception--
not sure why it's not.
Here's phobos code from github:
/// Hash syntax for json objects.
/// Throws $(D JSONException) if $(D type) is not $(D
JSON_TYPE.OBJECT).
ref inout(JSONValue) opIndex(string k) inout
{
enforceEx!JSONException(type == JSON_TYPE.OBJECT,
JSONValue is not an object);
return *enforceEx!JSONException(k in store.object,
Key not found: ~ k);
}
Added in
https://github.com/D-Programming-Language/phobos/commit/13fbd451bcca923cf8d1028495e58aa88cc7efeb
Maybe phobos is not up to date for me???
Re: Segfault games with factorials
On Thursday, 24 July 2014 at 14:59:16 UTC, Darren wrote: It does seem that's the case. Which is odd, as I thought that DMD and LDC did TCO. Not in this case obviously. DMD doesn't do it with the :? operator: https://issues.dlang.org/show_bug.cgi?id=3713
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend
using http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency that
is now corrected. You will get an exception thrown now and
everything should work how you expect.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:34:22 UTC, Ali Çehreli wrote: On 07/24/2014 08:29 AM, Pavel wrote: writeln(parsed[fail] == null); Now compiler complains: Error: incompatible types for ((parsed.opIndex(fail)) == (null)): 'JSONValue' and 'typeof(null)' WAT?! Comparing against null should be done with the 'is' operator, not the == operator: if (x is null) Ali My compiler disagreed: app.d(8): Error: incompatible types for ((parsed.opIndex(fail)) is (null)): 'JSONValue' and 'typeof(null)'
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend
using http://vibed.org/api/vibe.data.json/ instead
I'm pretty sure it's improving, but it has that Java disease,
which is creating new Types, which are just wrappers for common
types.
Why don't just use Variant[string] for objects, and Variant[] for
arrays. This way you won't be putting another layer of knowledge
for those who work with std.json.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:42:58 UTC, Pavel wrote:
On Thursday, 24 July 2014 at 15:38:06 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend
using http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency
that is now corrected. You will get an exception thrown now
and everything should work how you expect.
Maybe. But still it's not the way I expect, any time you check
for non-existing property you must consider exception, which is
very heavy to deal with in such a situation. I'd rather expect
to get null, whenever I try to fetch non-existing property, and
not an exception.
That's purely my point, and I don't claim to be right in this
way. It's up to Phobos maintainers to decide how to reprent
JSON parsing results.
Also that's why you just can't write:
writeln(fail in parsed);
As JSONValue is just a wrapper: non-native, non-intuitive.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:38:06 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend
using http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency
that is now corrected. You will get an exception thrown now and
everything should work how you expect.
Maybe. But still it's not the way I expect, any time you check
for non-existing property you must consider exception, which is
very heavy to deal with in such a situation. I'd rather expect to
get null, whenever I try to fetch non-existing property, and not
an exception.
That's purely my point, and I don't claim to be right in this
way. It's up to Phobos maintainers to decide how to reprent JSON
parsing results.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:42:58 UTC, Pavel wrote:
On Thursday, 24 July 2014 at 15:38:06 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend
using http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency
that is now corrected. You will get an exception thrown now
and everything should work how you expect.
Maybe. But still it's not the way I expect, any time you check
for non-existing property you must consider exception, which is
very heavy to deal with in such a situation. I'd rather expect
to get null, whenever I try to fetch non-existing property, and
not an exception.
You can turn your json object into an AA object and then use in
to check for existence (I know it is not very intuitive):
JSONValue[string] jsonAA = parsed.object;
if ( fail in jsonAA )
s = jsonAA[fail].str;
That's purely my point, and I don't claim to be right in this
way. It's up to Phobos maintainers to decide how to reprent
JSON parsing results.
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:48:32 UTC, Edwin van Leeuwen
wrote:
On Thursday, 24 July 2014 at 15:42:58 UTC, Pavel wrote:
On Thursday, 24 July 2014 at 15:38:06 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still
recommend using http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency
that is now corrected. You will get an exception thrown now
and everything should work how you expect.
Maybe. But still it's not the way I expect, any time you check
for non-existing property you must consider exception, which
is very heavy to deal with in such a situation. I'd rather
expect to get null, whenever I try to fetch non-existing
property, and not an exception.
You can turn your json object into an AA object and then use in
to check for existence (I know it is not very intuitive):
JSONValue[string] jsonAA = parsed.object;
if ( fail in jsonAA )
s = jsonAA[fail].str;
That's purely my point, and I don't claim to be right in this
way. It's up to Phobos maintainers to decide how to reprent
JSON parsing results.
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would
output null?
PS: Sorry, for such an emotional boom, I'm so frustrated right
now.
Re: D JSON (WAT?!)
Am 24.07.2014 17:54, schrieb Pavel:
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would output null?
PS: Sorry, for such an emotional boom, I'm so frustrated right now.
Relax :-)
And see http://dlang.org/hash-map.html
in doesn't just return if something is in a map.
If it is, it returns a pointer to the value, otherwise null.
Thus null.
Cheers,
Daniel
Re: D JSON (WAT?!)
Pavel: writeln(cast(bool)(fail in parsed)); Produces false... but why on earth boolean expression would output null? In D if you perform an associative array in, the return isn't a boolean but a pointer. It's zero if the item is not present. And it's a valid pointer to the value if the key is present. Bye, bearophile
Re: D JSON (WAT?!)
On Thu, Jul 24, 2014 at 03:54:20PM +, Pavel via Digitalmars-d-learn wrote:
[...]
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would output null?
It's not a boolean expression. The 'in' operator returns a pointer.
Rationale: avoid double lookups, for example:
if (auto ptr = key in assocArray) {
doSomething(*ptr);
}
T
--
The right half of the brain controls the left half of the body. This means that
only left-handed people are in their right mind. -- Manoj Srivastava
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:59:52 UTC, Daniel Gibson wrote:
Am 24.07.2014 17:54, schrieb Pavel:
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would
output null?
PS: Sorry, for such an emotional boom, I'm so frustrated right
now.
Relax :-)
And see http://dlang.org/hash-map.html
in doesn't just return if something is in a map.
If it is, it returns a pointer to the value, otherwise null.
Thus null.
Cheers,
Daniel
Thanks to all you folks who explained in operator for me. My
bad.
Let's focus on the real problem, which is JSON wrapper class.
Is it needed? Wouldn't it be better to get AA from parseJSON?
Re: D JSON (WAT?!)
On Thu, 24 Jul 2014 15:54:20 +, Pavel wrote:
On Thursday, 24 July 2014 at 15:48:32 UTC, Edwin van Leeuwen wrote:
On Thursday, 24 July 2014 at 15:42:58 UTC, Pavel wrote:
On Thursday, 24 July 2014 at 15:38:06 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no output at
all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still recommend using
http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency that is
now corrected. You will get an exception thrown now and everything
should work how you expect.
Maybe. But still it's not the way I expect, any time you check for
non-existing property you must consider exception, which is very heavy
to deal with in such a situation. I'd rather expect to get null,
whenever I try to fetch non-existing property, and not an exception.
You can turn your json object into an AA object and then use in to
check for existence (I know it is not very intuitive):
JSONValue[string] jsonAA = parsed.object;
if ( fail in jsonAA )
s = jsonAA[fail].str;
That's purely my point, and I don't claim to be right in this way.
It's up to Phobos maintainers to decide how to reprent JSON parsing
results.
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object; writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would output
null?
PS: Sorry, for such an emotional boom, I'm so frustrated right now.
The `in` expression produces a pointer to the value in the container, not
a bool. If the key is not present in the container, it returns the null
pointer. So this test is working precisely as expected. Here are some
common idioms for working with `in` and associative arrays:
// if with declaration
if (auto vptr = fail in parsed.object)
writeln(here's the value: , *vptr);
else
writeln(fail is not in the JSON);
// coerce to bool
writeln(!!(fail in parsed.object));
// get the value or a default value
writeln(parsed.object.get(fail, someDefaultJson));
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 15:54:21 UTC, Pavel wrote:
On Thursday, 24 July 2014 at 15:48:32 UTC, Edwin van Leeuwen
wrote:
On Thursday, 24 July 2014 at 15:42:58 UTC, Pavel wrote:
On Thursday, 24 July 2014 at 15:38:06 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:32:29 UTC, John Colvin wrote:
On Thursday, 24 July 2014 at 15:15:37 UTC, Pavel wrote:
Ok, let me start with the sample code:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr);
string s = parsed[fail].str;
writeln(s == );
writeln(s is null);
writeln(s);
}
Running rdmd app.d doesn't produce any output.
Can anyone explain such a behavior???
PS: Running dmd v2.065 on Linux x64.
It's a bug in std.json (you should get a segfault, not no
output at all)
It is fixed now and I'm pretty sure it will be in 2.066
std.json has been improved a lot, but I would still
recommend using http://vibed.org/api/vibe.data.json/ instead
perhaps bug is too strong a word, but it was a deficiency
that is now corrected. You will get an exception thrown now
and everything should work how you expect.
Maybe. But still it's not the way I expect, any time you
check for non-existing property you must consider exception,
which is very heavy to deal with in such a situation. I'd
rather expect to get null, whenever I try to fetch
non-existing property, and not an exception.
You can turn your json object into an AA object and then use
in to check for existence (I know it is not very intuitive):
JSONValue[string] jsonAA = parsed.object;
if ( fail in jsonAA )
s = jsonAA[fail].str;
That's purely my point, and I don't claim to be right in this
way. It's up to Phobos maintainers to decide how to reprent
JSON parsing results.
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would
output null?
PS: Sorry, for such an emotional boom, I'm so frustrated right
now.
The in operator in d returns a pointer to the element found or
null.
This might be a little confusing at first* but it makes sense for
efficiency reasons. There is often a lot overlap between the work
needed to test for presence and the work needed to fetch an
element.
For types where fetching elements is a significant extra cost you
can always define a `bool contains(K key) { /* ... */ }` so a
user can avoid this cost when appropriate.
*although to be honest it's just a different reading:
`b in c` can be read as the b in c or is b in c?
Re: D JSON (WAT?!)
On Thu, 24 Jul 2014 16:04:01 +, Pavel wrote: Thanks to all you folks who explained in operator for me. My bad. Let's focus on the real problem, which is JSON wrapper class. Is it needed? Wouldn't it be better to get AA from parseJSON? The following are valid JSON: auto json1 = parseJSON(`1`); auto json2 = parseJSON(`foo`); auto json3 = parseJSON(`[1, 2, 3]`); None of these fit naturally into an JSONValue[string] return type.
Passing an array by reference?
1 class Test
2 {
3 int[][] array;
4 this(ref int[][] d)
5 {
6 array = d;
7 }
8
9 }
10
11 void main()
12 {
13 Test t = new Test([[1,1],[1,1]]); //does not compile
14 }
15
what is the best way to pass a literal ([[1,2],[3,4]]) by
reference? Is using ref the best way? I am still a bit fuzzy with
in/out and scope
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 16:02:12 UTC, H. S. Teoh via
Digitalmars-d-learn wrote:
On Thu, Jul 24, 2014 at 03:54:20PM +, Pavel via
Digitalmars-d-learn wrote:
[...]
Guess what, here's a new snippet:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(FaILED!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
writeln(fail in parsed);
}
Output is:
null
WAT?!
Ofcourse, writing like:
writeln(cast(bool)(fail in parsed));
Produces false... but why on earth boolean expression would
output null?
It's not a boolean expression. The 'in' operator returns a
pointer.
Rationale: avoid double lookups, for example:
if (auto ptr = key in assocArray) {
doSomething(*ptr);
}
T
Thanks once again. Now I finally get this thing done with code
like this:
import std.stdio;
import std.json;
void main() {
scope(failure) writeln(Failure!!);
string jsonStr = `{ name: 1, type: r }`;
auto parsed = parseJSON(jsonStr).object;
auto found = fail in parsed;
if (found !is null) {
string s = found.str;
writeln(s);
} else {
writeln(No such key);
}
}
Still focus on wrapper class discussion :)
Re: D JSON (WAT?!)
On Thursday, 24 July 2014 at 16:09:25 UTC, Justin Whear wrote: On Thu, 24 Jul 2014 16:04:01 +, Pavel wrote: Thanks to all you folks who explained in operator for me. My bad. Let's focus on the real problem, which is JSON wrapper class. Is it needed? Wouldn't it be better to get AA from parseJSON? The following are valid JSON: auto json1 = parseJSON(`1`); auto json2 = parseJSON(`foo`); auto json3 = parseJSON(`[1, 2, 3]`); None of these fit naturally into an JSONValue[string] return type. Oh, man! You're wrong!!! Read: http://www.json.org/, and try putting 1 or foo as JSON string here: http://jsonlint.com/
Re: Passing an array by reference?
On Thursday, 24 July 2014 at 16:06:00 UTC, Rishub Nagpal wrote:
1 class Test
2 {
3 int[][] array;
4 this(ref int[][] d)
5 {
6 array = d;
7 }
8
9 }
10
11 void main()
12 {
13 Test t = new Test([[1,1],[1,1]]); //does not compile
14 }
15
what is the best way to pass a literal ([[1,2],[3,4]]) by
reference? Is using ref the best way? I am still a bit fuzzy
with in/out and scope
Why do you need to pass the array by reference? D's slices are
just windows on to memory, they don't copy the contents when you
pass them around.
Anyway, if you do need ref, the problem is that [[1,1],[1,1]] is
a temporary, an rvalue, and ref can't take rvalues.
Re: D JSON (WAT?!)
On 7/24/14, 1:09 PM, Justin Whear wrote: On Thu, 24 Jul 2014 16:04:01 +, Pavel wrote: Thanks to all you folks who explained in operator for me. My bad. Let's focus on the real problem, which is JSON wrapper class. Is it needed? Wouldn't it be better to get AA from parseJSON? The following are valid JSON: auto json1 = parseJSON(`1`); auto json2 = parseJSON(`foo`); auto json3 = parseJSON(`[1, 2, 3]`); None of these fit naturally into an JSONValue[string] return type. Nope, a JSON can only be an array or an object (hash). In Crystal we have this definition: alias JsonType = Nil | Bool | Int64 | Float64 | String | Array(JsonType) | Hash(String, JsonType) (note that this is a recursive type definition) Then when you do Json.parse you get a value whose type is Array(JsonType) | Hash(String, JsonType). The good thing about this is that Json.parse gives you types that already exist: Array, Hash, Int64, etc. No need to define extra types and no need for users to learn a new API with new types. Wouldn't something like this be better to do in D? That is, return something that is an array or an associative array...
Re: D JSON (WAT?!)
On Thu, 24 Jul 2014 13:49:27 -0300, Ary Borenszweig wrote: Nope, a JSON can only be an array or an object (hash). Ary, can you point out the place in the spec where this is specified? Not to be pedantic, but the spec only seems to define a JSON value, not a JSON document.
Re: D JSON (WAT?!)
On Thu, 24 Jul 2014 16:14:15 +, Pavel wrote: On Thursday, 24 July 2014 at 16:09:25 UTC, Justin Whear wrote: On Thu, 24 Jul 2014 16:04:01 +, Pavel wrote: Thanks to all you folks who explained in operator for me. My bad. Let's focus on the real problem, which is JSON wrapper class. Is it needed? Wouldn't it be better to get AA from parseJSON? The following are valid JSON: auto json1 = parseJSON(`1`); auto json2 = parseJSON(`foo`); auto json3 = parseJSON(`[1, 2, 3]`); None of these fit naturally into an JSONValue[string] return type. Oh, man! You're wrong!!! Read: http://www.json.org/, and try putting 1 or foo as JSON string here: http://jsonlint.com/ Nope, while the spec calls out objects and arrays as the structural elements of JSON, it never requires (anywhere that I can find) that a complete JSON document have one of these at the root. A valid JSON value is defined as A JSON value can be an object, array, number, string, true, false, or null[1] Thus the parseJSON function is defined as parsing as JSONValue. 1 http://www.ecma-international.org/publications/files/ECMA-ST/ ECMA-404.pdf, p2
Re: How to copy an object to separate allocated memory?
On Thu, 24 Jul 2014 17:05:17 +, Gary Willoughby wrote: I was reading Ali's book (http://ddili.org/ders/d.en/index.html) and saw this piece of code on how to get the true size of an object: MyClass* buffer = cast(MyClass*)GC.calloc(__traits(classInstanceSize, MyClass) * 10); That got me thinking, how would i actually 'fill' this memory with instances of that class? std.conv.emplace: http://dlang.org/phobos/std_conv.html#.emplace
How to copy an object to separate allocated memory?
I was reading Ali's book (http://ddili.org/ders/d.en/index.html) and saw this piece of code on how to get the true size of an object: MyClass* buffer = cast(MyClass*)GC.calloc(__traits(classInstanceSize, MyClass) * 10); That got me thinking, how would i actually 'fill' this memory with instances of that class?
Re: How to copy an object to separate allocated memory?
Am 24.07.2014 19:05, schrieb Gary Willoughby: I was reading Ali's book (http://ddili.org/ders/d.en/index.html) and saw this piece of code on how to get the true size of an object: MyClass* buffer = cast(MyClass*)GC.calloc(__traits(classInstanceSize, MyClass) * 10); That got me thinking, how would i actually 'fill' this memory with instances of that class? std.conv.emplace()
Re: How to copy an object to separate allocated memory?
On Thursday, 24 July 2014 at 17:05:18 UTC, Gary Willoughby wrote: I was reading Ali's book (http://ddili.org/ders/d.en/index.html) and saw this piece of code on how to get the true size of an object: MyClass* buffer = cast(MyClass*)GC.calloc(__traits(classInstanceSize, MyClass) * 10); That got me thinking, how would i actually 'fill' this memory with instances of that class? std.conv.emplace
Re: How to copy an object to separate allocated memory?
On Thu, 24 Jul 2014 17:07:29 +, Justin Whear wrote: On Thu, 24 Jul 2014 17:05:17 +, Gary Willoughby wrote: I was reading Ali's book (http://ddili.org/ders/d.en/index.html) and saw this piece of code on how to get the true size of an object: MyClass* buffer = cast(MyClass*)GC.calloc(__traits(classInstanceSize, MyClass) * 10); That got me thinking, how would i actually 'fill' this memory with instances of that class? std.conv.emplace: http://dlang.org/phobos/std_conv.html#.emplace Wow, the ninja'ing is strong today.
Mocking serial device
Hello, I am writing an application that connects to a serial device in /dev/ttyUSB0 and trows some binary data back and forth. How can i mock and run some unit testing without having to connect to the device every time? -- Regards, Alfredo Palhares
dual with statement
I was playing around with use of the dual WITH statement. I
like the idea, since it makes the code within the with cleaner.
Also, I got the impression from one of the conference
presentations ... maybe the one on the ARM debug ... that there
are some additional optimizations available that the compiler
processes the WITH statement block.
Anyway, a problem I ran into was if two structures had the same
member names, for example struct ar.r and ar.psm in this case
below. In this case, there was no way for the compiler to
determine from which structure to get the member.
void calc_per_sec_met(ref All ar){
with (ar.r) with(ar.psm) {
double per_sec = proc_cyc/ref_clock;
d = (a+c)*per_sec;
e = (c==0)?0:(a+b)/c;
}
}
ok, so I guess I could make all the member names unique in the
different structures, but that's kind of ugly.
Also, what happens if using two structs of the same type in a
WITH statement.
Seems like something like this would help, which I believe I've
seen used in database queries ...
with (ar.r1 as r1) with (ar.r2 as r2){
auto sum = r1.a + r2.a;
}
Re: Mocking serial device
On Thu, 24 Jul 2014 17:15:02 +, Alfredo Palhares wrote: Hello, I am writing an application that connects to a serial device in /dev/ttyUSB0 and trows some binary data back and forth. How can i mock and run some unit testing without having to connect to the device every time? How about capturing some data from the device and writing it to a file? When you want to test, open the test data file instead of the device file.
Re: Mocking serial device
Hello, How about capturing some data from the device and writing it to a file? When you want to test, open the test data file instead of the device file. That would not work since the data is two way, for the device to even trow data at me I need to send some values to it. -- Regards, Alfredo Palhares
Appender.put return value
Is there a big reason why Appender.put doesn't return this? http://dpaste.dzfl.pl/bb840e3e349e It would allow for convenient chaining. :
Re: Appender.put return value
Offtop It's better to return this and have return type ref auto i think.
Re: D JSON (WAT?!)
On 7/24/14, 1:58 PM, Justin Whear wrote: On Thu, 24 Jul 2014 13:49:27 -0300, Ary Borenszweig wrote: Nope, a JSON can only be an array or an object (hash). Ary, can you point out the place in the spec where this is specified? Not to be pedantic, but the spec only seems to define a JSON value, not a JSON document. You are right, my bad. According to Wikipedia (which has links to RFCs): Early versions of JSON (such as specified by RFC 4627) required that a valid JSON document must consist of only an object or an array type—though they could contain other types within them. This restriction was relaxed starting with RFC 7158, so that a JSON document may consist entirely of any possible JSON typed value.
Create a general array
Hi! Can I somehow make a general array where I can store everykind of object? doubles, ints, float, class objects? Or is there any method for it?
