digitalmars.D.learn - std.json questions
- tired_eyes (50/50) Apr 25 2015 Hello, D community!
- Dan Olson (62/88) Apr 25 2015 Hi and welcome to D land. I see discussions on how std.json needs to be
- rcorre (4/8) Apr 25 2015 See http://wiki.dlang.org/Review_Queue. std.data.json is the
- Baz (8/10) Apr 25 2015 What you clearly need is a serializer:
- tired_eyes (3/3) Apr 26 2015 Thank everybody for you help. For now, yajl-d seems to be an
- extrawurst (3/13) Apr 26 2015 too bad D:YAML links are broken, do you know where to find that
- weaselcat (2/21) Apr 26 2015 https://github.com/kiith-sa/D-YAML
- Pierre Krafft (2/12) Apr 27 2015 Also http://code.dlang.org/search?q=json
Hello, D community!
I'm pretty new to D and to compiled languages in general, and
have primarily web background (PHP, JS), when JSON workflow is
very organic. I was always sure that JSON is a simple thing, but
std.json proves me wrong. So may I have a little advice from more
experienced D folk?
Say, I have a simple JSON file:
{
"entities" : [
{
"x" : 0,
"y" : 0,
"texture" : "box1"
},
{
"x" : 100,
"y" : 200,
"texture" : "box2",
"isControllable" : true
}
]
}
First issue: what is the proper ("idiomatic") way to conver
JSONValue to the proper types?
Second: what is the proper way of handling boolean values in JSON
(how to convert JSON_TYPE.TRUE and JSON_TYPE.FALSE to bool)?
Righ now I'm doing is something like this:
string data = readText("file.json");
JSONValue[string] parsedData = parseJSON(data).object;
JSONValue[] etities = stateData["entities"].array;
foreach(e; entities) {
int x = to!int(e["x"].integer);
int y = to!int(e["y"].integer);
string texture = stripExtension(e["texture"].str);
auto isControllable = "isControllable" in e;
if (isControllable !is null) {
if (e["isControllable"].type == JSON_TYPE.TRUE) {
isControllable = true;
} else {
isControllable = false;
}
}
}
I think this is ugly and clunky approach, what is the beautiful
one?
A brief look at code.dlang.org gives us 7 (!) additional JSON
libraries. Keeping in mind that D community isn't so huge, I
think I'm not the only person struggling with std.json. Are there
any plans on upgrading it?
Thank you in advance!
Apr 25 2015
Dan Olson <zans.is.for.cans yahoo.com>
"tired_eyes" <pastuhov85 gmail.com> writes:
First issue: what is the proper ("idiomatic") way to conver JSONValue
to the proper types?
Second: what is the proper way of handling boolean values in JSON (how
to convert JSON_TYPE.TRUE and JSON_TYPE.FALSE to bool)?
Righ now I'm doing is something like this:
string data = readText("file.json");
JSONValue[string] parsedData = parseJSON(data).object;
JSONValue[] etities = stateData["entities"].array;
foreach(e; entities) {
int x = to!int(e["x"].integer);
int y = to!int(e["y"].integer);
string texture = stripExtension(e["texture"].str);
auto isControllable = "isControllable" in e;
if (isControllable !is null) {
if (e["isControllable"].type == JSON_TYPE.TRUE) {
isControllable = true;
} else {
isControllable = false;
}
}
}
I think this is ugly and clunky approach, what is the beautiful one?
A brief look at code.dlang.org gives us 7 (!) additional JSON
libraries. Keeping in mind that D community isn't so huge, I think I'm
not the only person struggling with std.json. Are there any plans on
upgrading it?
Hi and welcome to D land. I see discussions on how std.json needs to be
upgraded. And it is not well documented.
I tried to progressively simplify the code that was posted to show what
can be done, but keeping the same spirit. Not necessarily beautiful,
but less verbose code. I did not see a simpler way to deal with bools in
the std.json code. Others here are experts on idiomatic D, they may
show something much better.
// First , make it work and show all types
void f1()
{
string data = readText("file.json");
JSONValue parsedData = parseJSON(data);
JSONValue entities = parsedData["entities"];
foreach(size_t index, e; entities) {
long x = e["x"].integer;
long y = e["y"].integer;
string texture = stripExtension(e["texture"].str);
bool isControllable = false;
if ("isControllable" in e) {
if (e["isControllable"].type == JSON_TYPE.TRUE) {
isControllable = true;
} else {
isControllable = false;
}
}
writefln("x %d y %d texture %s isControllable %s",
x, y, texture, isControllable);
}
}
// Next, let compiler figure types for us
void f2()
{
auto data = readText("file.json");
auto parsedData = parseJSON(data);
auto entities = parsedData["entities"];
foreach(size_t _, e; entities) {
auto x = e["x"].integer;
auto y = e["y"].integer;
auto texture = stripExtension(e["texture"].str);
bool isControllable = false;
if ("isControllable" in e) {
isControllable = e["isControllable"].type == JSON_TYPE.TRUE;
}
writefln("x %d y %d texture %s isControllable %s",
x, y, texture, isControllable);
}
}
// A little simpler isControllable.
void f3()
{
auto parsedData = readText("file.json").parseJSON;
foreach(size_t _, e; parsedData["entities"]) {
auto x = e["x"].integer;
auto y = e["y"].integer;
auto texture = stripExtension(e["texture"].str);
auto isControllable = "isControllable" in e &&
e["isControllable"].type == JSON_TYPE.TRUE;
writefln("x %d y %d texture %s isControllable %s",
x, y, texture, isControllable);
}
}
Apr 25 2015
On Saturday, 25 April 2015 at 09:56:25 UTC, tired_eyes wrote:A brief look at code.dlang.org gives us 7 (!) additional JSON libraries. Keeping in mind that D community isn't so huge, I think I'm not the only person struggling with std.json. Are there any plans on upgrading it?See http://wiki.dlang.org/Review_Queue. std.data.json is the proposed replacement for the current phobos json implementation. There is also supposedly std.serialization in the works.
Apr 25 2015
On Saturday, 25 April 2015 at 09:56:25 UTC, tired_eyes wrote:I think this is ugly and clunky approach, what is the beautiful one?What you clearly need is a serializer: look at these: http://wiki.dlang.org/Libraries_and_Frameworks#Serialization and also: https://github.com/search?utf8=✓&q=serializer+language%3AD&type=Repositories&ref=searchresults some of them might have an API to save load an object or a struct in a single call.
Apr 25 2015
Thank everybody for you help. For now, yajl-d seems to be an optimal for my task, however will keep an eye for stdx.data.json too.
Apr 26 2015
On Saturday, 25 April 2015 at 18:30:33 UTC, Baz wrote:On Saturday, 25 April 2015 at 09:56:25 UTC, tired_eyes wrote:too bad D:YAML links are broken, do you know where to find that project ?I think this is ugly and clunky approach, what is the beautiful one?What you clearly need is a serializer: look at these: http://wiki.dlang.org/Libraries_and_Frameworks#Serialization and also: https://github.com/search?utf8=✓&q=serializer+language%3AD&type=Repositories&ref=searchresults some of them might have an API to save load an object or a struct in a single call.
Apr 26 2015
On Sunday, 26 April 2015 at 17:14:22 UTC, extrawurst wrote:On Saturday, 25 April 2015 at 18:30:33 UTC, Baz wrote:https://github.com/kiith-sa/D-YAMLOn Saturday, 25 April 2015 at 09:56:25 UTC, tired_eyes wrote:too bad D:YAML links are broken, do you know where to find that project ?I think this is ugly and clunky approach, what is the beautiful one?What you clearly need is a serializer: look at these: http://wiki.dlang.org/Libraries_and_Frameworks#Serialization and also: https://github.com/search?utf8=✓&q=serializer+language%3AD&type=Repositories&ref=searchresults some of them might have an API to save load an object or a struct in a single call.
Apr 26 2015
On Saturday, 25 April 2015 at 18:30:33 UTC, Baz wrote:On Saturday, 25 April 2015 at 09:56:25 UTC, tired_eyes wrote:Also http://code.dlang.org/search?q=jsonI think this is ugly and clunky approach, what is the beautiful one?What you clearly need is a serializer: look at these: http://wiki.dlang.org/Libraries_and_Frameworks#Serialization and also: https://github.com/search?utf8=✓&q=serializer+language%3AD&type=Repositories&ref=searchresults some of them might have an API to save load an object or a struct in a single call.
Apr 27 2015