Hi Nick.
Thanks again.
I will try the example you gave but it does appear no have a lot more
boiler plate than the original example and I just want to make sure that is
really needed (the least code I have to add for this, the better, as I will
do a complete rewrite yo use the latest Lucy anyway). Here was the original
sample code that worked for me:
typedef struct MyAnalyzer MyAnalyzer;
// Transform() is the central Analyzer method. Check out the
// documentation in Analyzer.cfh and various implementations; that
// should give you enough to cargo cult your own version.
static Inversion*
S_MyAnalyzer_Transform_IMP(MyAnalyzer *self, Inversion *inversion) {
return (Inversion*)INCREF(inversion);
}
// Create a subclass at runtime.
static Class*
S_class_var(void) {
StackString *class_name = SSTR_WRAP_UTF8("MyAnalyzer", 10);
Class *klass = Class_fetch_class((String*)class_name);
if (!klass) {
klass = Class_singleton((String*)class_name, ANALYZER);
Class_Override(klass,
(cfish_method_t)S_MyAnalyzer_Transform_IMP,
LUCY_Analyzer_Transform_OFFSET);
}
return klass;
}
// Constructor.
MyAnalyzer*
MyAnalyzer_new(void) {
Class *klass = S_class_var();
return (MyAnalyzer*)Class_Make_Obj(klass);
}
My main worry with your new example is that there is a considerable amount
of code being written in main and this will all go inside a library.
Because for now I am basically cargo-culting my way around this, I am not
sure what would be the best point to do that initialization. Would doing it
in _new work anyway?
Thanks again.
On Sun, Mar 5, 2017 at 3:32 PM Nick Wellnhofer <[email protected]> wrote:
> On 05/03/2017 17:26, Bruno Albuquerque wrote:
> > So, my question is: Using the trick of overriding specific methods form
> > Analyzer during runtime, is there a way I can also create my own ivars
> and
> > attach it to my overriden analyzer?
>
> Yes, this is possible. See the example code below (based on Lucy 0.6). Note
> that you should implement Equals, Dump, and Load methods if you have an
> Analyzer with ivars. See the Lucy Analyzers for guidance:
>
> https://github.com/apache/lucy/tree/master/core/Lucy/Analysis
>
> Another option is to write your own Clownfish parcel. Then the Clownfish
> compiler 'cfc' will create all the boilerplate code for you.
>
> https://lucy.apache.org/docs/c/Clownfish/Docs/WritingClasses.html
>
> > While we are at this, this is all Lucy 0.4.2 (yeah, I know, old) and I am
> > considering moving to the latest version mostly due to the now included
> > golang bindings. I didn't look a lot at the golang bindings yet but will
> it
> > be possible to create a new analyzer in a non-hackish way and entirely in
> > go using it?
>
> Extending Lucy classes from Go isn't supported yet.
>
> Nick
>
>
> #define CFISH_USE_SHORT_NAMES
> #define LUCY_USE_SHORT_NAMES
>
> #include <stdio.h>
>
> #include "Clownfish/Class.h"
> #include "Lucy/Analysis/Analyzer.h"
> #include "Lucy/Analysis/Inversion.h"
>
> typedef struct MyAnalyzer MyAnalyzer;
>
> typedef struct {
> int i;
> const char *p;
> } MyAnalyzerIVARS;
>
> Class *MYANALYZER;
> uint32_t MyAnalyzer_IVARS_OFFSET;
>
> static CFISH_INLINE MyAnalyzerIVARS*
> MyAnalyzer_IVARS(MyAnalyzer *self) {
> char *ptr = (char*)self + MyAnalyzer_IVARS_OFFSET;
> return (MyAnalyzerIVARS*)ptr;
> }
>
> Analyzer*
> MyAnalyzer_new() {
> MyAnalyzer *self = (MyAnalyzer*)Class_Make_Obj(MYANALYZER);
> MyAnalyzerIVARS *const ivars = MyAnalyzer_IVARS(self);
> ivars->i = 42;
> ivars->p = "abc";
> return (Analyzer*)self;
> }
>
> Inversion*
> MyAnalyzer_Transform_IMP(MyAnalyzer *self, Inversion *inversion) {
> MyAnalyzerIVARS *const ivars = MyAnalyzer_IVARS(self);
> printf("i=%d\n", ivars->i);
> return (Inversion*)INCREF(inversion);
> }
>
> int
> main() {
> lucy_bootstrap_parcel();
>
> cfish_ClassSpec class_spec = {
> &MYANALYZER,
> &ANALYZER,
> "MyNamespace::MyAnalyzer",
> sizeof(MyAnalyzerIVARS),
> &MyAnalyzer_IVARS_OFFSET,
> 0,
> 0,
> 0,
> 0
> };
> cfish_ParcelSpec parcel_spec = {
> &class_spec,
> NULL,
> NULL,
> NULL,
> 1 // Number of classes.
> };
>
> Class_bootstrap(&parcel_spec);
> Class_Override(MYANALYZER, (cfish_method_t)MyAnalyzer_Transform_IMP,
> LUCY_Analyzer_Transform_OFFSET);
>
> Analyzer *analyzer = MyAnalyzer_new();
> Analyzer_Transform(analyzer, NULL);
> DECREF(analyzer);
>
> return 0;
> }
>
>
