pyd and converting arrays of strings

[Laeeth Isharc via Digitalmars-d-learn]

On Wednesday, 18 March 2015 at 20:58:56 UTC, John Colvin wrote:
> On Wednesday, 18 March 2015 at 17:09:27 UTC, Laeeth Isharc 
> wrote:
>> Hi
>>
>> I am using PyD with latest stable LDC on Arch Linux 64 bit.
>>
>> I have various structures I am trying to wrap to pass to 
>> python.  For example:
>>
>> struct PlotLines
>> {
>> 	KPDateTime[] start_dates;
>> 	KPDateTime[] end_dates;
>> 	double[] y;
>> 	string[] colors;
>> 	long[] weights;
>> 	string[] styles;
>> }
>>
>> import pyd.pyd;
>> extern(C) void PydMain()
>> {
>> def!(bokehDownload,PyName!"bokeh_download", BokehBars 
>> function(string,bool))();
>> def!(bokehCountdown,PyName!"bokeh_countdown",CanvasTable 
>> function(BokehBars,bool,bool))();
>> module_init();
>> wrap_struct!(BokehBars,Member!("dates"),Member!("opens"),Member!("highs"),Member!("lows"),Member!("closes"),Member!("volumes"),Member!("openinterests"));
>> wrap_struct!(KPDateTime,Member!"year",Member!"month",Member!"day",Member!"hour",Member!"minute",Member!"second");
>> wrap_struct!(CanvasTable,Member!"plot_title",Member!"x_label",Member!"y_label",Member!"annotations",Member!"lines",Member!"bars",Member!"studies",Member!"grid_sequence");
>> wrap_struct!(PlotLines,Member!"start_dates",Member!"end_dates",Member!"y",Member!"colors",Member!"weights",Member!"styles");
>> wrap_struct!(PlotStudy,Member!"title",Member!"dates",Member!"lines",Member!"overbought",Member!"oversold");
>> wrap_struct!(PlotAnnotations,Member!"directions",Member!"dates",Member!"y",Member!"weights",Member!"values",Member!"colors",Member!"styles");
>> }
>>
>> PyD doesn't seem to want to wrap a string[] member:
>>
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/make_object.d(773): 
>> Error: cannot implicitly convert expression 
>> (python_to_d(item)) of type string to dchar[]
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/make_object.d(740): 
>> Error: function 
>> pyd.make_object.python_iter_to_d!(string[]).python_iter_to_d 
>> no return exp; or assert(0); at end of function
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/make_object.d(482): 
>> Error: template instance 
>> pyd.make_object.python_iter_to_d!(string[]) error instantiating
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/struct_wrap.d-mixin-73(73):
>>       instantiated from here: python_to_d!(string[])
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/struct_wrap.d(105):
>>       instantiated from here: wrapped_member!(PlotLines*, 
>> "colors", "rw")
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/class_wrap.d(1503):
>>       instantiated from here: call!("PlotLines", PlotLines*)
>> /home/laeeth/anaconda/lib/python2.7/site-packages/pyd/infrastructure/pyd/class_wrap.d(1474):
>>       instantiated from here: _wrap_class!(PlotLines, 
>> "PlotLines", "", "", Member!"start_dates", Member!"end_dates", 
>> Member!"y", Member!"colors", Member!"weights", Member!"styles")
>> /btrfs0/mirrored/kprop/core/prod/kprop/technical/demark/countdown/main13.d(72):
>>       instantiated from here: wrap_struct!(PlotLines, 
>> Member!"start_dates", Member!"end_dates", Member!"y", 
>> Member!"colors", Member!"weights", Member!"styles")
>> error: command 'ldc2' failed with exit status 1
>>
>> Any thoughts on whether I am doing something wrong, and if it 
>> is a PyD problem, how to circumvent it?
>>
>>
>> Thanks.
>>
>>
>> Laeeth.
>
> A quick glance over class_wrap.d suggests that pyd may not 
> handle string[] correctly. I think it has the necessary special 
> casing to deal with ElementType!string being dchar (not char), 
> but this isn't triggered for string[]. I see you've filed a 
> bug, hopefully someone will take a look. I might have time soon 
> if no one else jumps on it.
>
> Can you use immutable(dchar)[][] instead of string[]? That 
> might work, but I haven't tested it.

Hi John.

dchar[] works, but I am not sure about immutable.  I turned the 
strings used to populate the struct into dchar by appending 
.array to the end (there may be a better way).

Thanks for looking at it.


Laeeth