Hi,
I changed CPLJSONObject/CPLJSONArray methods string parameters to
std::string and merged last trunk changes.
Still leave 3 methods with const char* to simplify code because
according to standard conversion sequence, methods with input (const
char*, const char*) parameters executes method with signature
(std:;string&, bool):
Add("key", "value") --> Add(std::string osName, bool bValue)
Set("key", "value") --> Set(std::string osName, bool bValue)
See notes in pull request
(https://github.com/OSGeo/gdal/pull/282#issuecomment-355766795).
I'm ready to merge current pull request into the trunk.
Best regards,
Dmitry
05.01.2018 23:43, Kurt Schwehr пишет:
My preference (and not speaking for the gdal community) for C++ classes
would be:
1. replace const char * -> const std::string &
2. replace CPLString -> std::string
std::string GetString(const std::string &soName, const std::string
&soDefault = "") const;
This is where it would be good to get input from others.
I base the above on maximizing safety while trying to let the compiler do
its best job at optimizing. Then in about 2022, we can see about
std::string_view :(
On Fri, Jan 5, 2018 at 12:26 PM, Dmitry Baryshnikov <[email protected]>
wrote:
Hi Kurt,
Can you explain what should be done in PR?
Do you mean to replace all const char* to?
1. const char* -> const CPLString &
const char *GetString(const char *pszName, const char *pszDefault = "")
const; ->
CPLString GetString(const CPLString &soName, const CPLString &soDefault =
"") const;
or
2. const char* -> const std::string &
const char *GetString(const char *pszName, const char *pszDefault = "")
const; ->
std::string GetString(const std::string &soName, const std::string
&soDefault = "") const;
or?
Best regards,
Dmitry
05.01.2018 18:54, Kurt Schwehr пишет:
+1 for wrapping the old C code in some cleaner abstractions!
But +10 for switching to a from the ground up C++ JSON library unless there
are clear reasons for a core C library (I don't think there are)
If we are talking about this kind of code, there are several things that
have bugged me in general about GDAL for a long time.
* Passing char *psz yada all over the place in pure C++ code. A const
std::string is usually not a noticeable expense and is a lot safer
* CPLString when std::string will do just fine. And we can write free
functions to operate on strings. I'm generally bothered by subclassing of
std::string as CPLString. After reading large amounts of C++ code, I think
it adds more confusion than it ever helps over having clean free
functions. Interop and analysis with CPLString's is no fun.
https://stackoverflow.com/questions/6006860/why-should-one-not-derive-from-c-std-string-class
-kurt
On Fri, Jan 5, 2018 at 7:44 AM, Sean Gillies <[email protected]>
<[email protected]> wrote:
Hi Dmitry,
I scanned the PR and it seems reasonable to me. I'm barely a C++
programmer at all and it's clear to me, more clear than before. That said,
I'm not a fan of wrapping things that could be replaced. Have you looked
into whether a more performant C++ JSON library could be used? I haven't
run the benchmarks, but json-c compares pretty poorly to others
inhttps://github.com/miloyip/nativejson-benchmark.
On Wed, Jan 3, 2018 at 12:04 PM, Dmitry Baryshnikov <[email protected]>
<[email protected]>
wrote:
Hi everybody,
Happy new year and lot of success in 2018!
I would like to discuss my pull request https://github.com/OSGeo/gdal/
pull/282
I created a thin wrapper around the json-c library which wide using in
GDAL.
This is C++ interface which hides C memory management and provides nice
API. The web or disk json documents reading chunk by chunk with progress
indication also added.
In future, the json-c can be easily switch to something other without
breaking the existing code.
The CPLJSONDocument/CPLJSONObject/CPLJSONArray usage examples can be
found in frmts/pds driver and c++ unit test in autotest/cpp/test_cpl.cpp.
Is this ready to merge into the trunk? Any objections?
Best regards,
Dmitry
_______________________________________________
gdal-dev mailing
[email protected]https://lists.osgeo.org/mailman/listinfo/gdal-dev
--
Sean Gillies
_______________________________________________
gdal-dev mailing
[email protected]https://lists.osgeo.org/mailman/listinfo/gdal-dev
_______________________________________________
gdal-dev mailing list
[email protected]
https://lists.osgeo.org/mailman/listinfo/gdal-dev
