> El 24 sept 2019, a las 4:35, Richard O'Keefe <rao...@gmail.com> escribió:
>
> What I want to do is to create a binding for the SoftPosit library.
> A typical function has an interface like
> quire16_t q16_fdp_add(quire16_t, posit16_t, posit16_t);
> where
> typedef struct { uint16_t v; } posit16_t;
> typedef struct { uint64_t v[2]; } quire16_t;
> A "quire" is a dot product accumulator.
> A "posit" is a number.
> {quire,posit}{8,16,32} are defined, and a number of other types.
Ok, so IIUC, what you need is:
1) define type aliases (e.g., typedef posit16_t uint_t)
2) define a couple of structs based on those types
I see in the booklet no documentation about type aliases so far, but in the
latest pharo version there are a couple of examples you can look at.
Type aliases can be defined as class variables in the class using the type, or
in a shared pool, if you mean to use those types in several places.
Take a look at FT2Types class side for an example, where the type FT_Error is
defined
FT2Types class>>initialize
...
FT_Error := 'long’.
…
and then used in a callout like this
FT2Face >> ffiGetKerningLeft: left_glyph right: right_glyph result: akerning
self ffiCall: #(FT_Error FT_Get_Kerning(self, FT_UInt left_glyph,
FT_UInt right_glyph, 2, FT_Vector *akerning ))
Then, to use those defined types in a struct definition, you only need to make
those type aliases (class vars) available in your struct, and use them in the
struct field definition
See for example FTMatrix
FTMatrix class >> fieldsDesc
^ #(
FT_Fixed xx
FT_Fixed xy
FT_Fixed yx
FT_Fixed yy
)
Hope this helps,
Guille
