OpenEuphoria

Re: C Struct Support

• Posted by raseunew Dec 30, 2010
• 1835 views

here's my first take on C structure support

 
cstruct.e 
 
namespace cstruct 
 
/* 

   reserved structure primitive names 
   (need associated byte sizes) 
*/ 
 
   int8 
   int16 
   int32 
   int64 
   uint8 
   uint16 
   uint32 
   uint64 
   float 
   double 
   byte 
   char 
   ubyte 
   uchar 
   word 
   dword 
   longlong 
   pointer 
 
struct   --// public type = atom 
 
--// create new memstruct 
 
public function new(sequence ns_struct) 
   return allocate(sizeof(ns_struct)) 
end function 
 
/* 

   string 
*/ 
mem_struct c_str 
   pointer( integer( 8, array, null_terminated ) ) chars 
end mem_struct 
 
/* 

   wide string 
*/ 
mem_struct wc_str 
   pointer( integer( 16, array, null_terminated ) ) wchars 
end mem_struct 
 
/* 

   allocate array of [n] items 
 
   expands to TYPE(TYPESIZE, array, N) n 
*/ 
mem_struct vector[N, TYPE=int32] 
   TYPE[N] v 
end mem_struct 
 
usage : 
 
basic.e 
 
namespace basic 
 
include cstruct.e as cs 
 
/* 

   person structure 
*/ 
 
mem_struct person 
   cs:uchar[32] name     null_terminated 
   cs:int32     age 
   cs:c_str     company 
   cs:wc_str    address1 
end mem_struct 
 
usage 2: 
 
test.e 
 
include cstruct.e as cs 
include basic.e   as basic 
 
/* 

   array of int32 
 
   expands to integer(32, array, 10) 
*/ 
 
cs:struct A = cs:new(basic:vector[10]) 
 
/* 

   array of int64 
 
   expands to integer(64, array, 10) 
*/ 
 
cs:struct B = cs:new(basic:vector[10, cs:int64]) 
 
--// single person 
 
cs:struct P = cs:new(basic:person()) 
 
--// assignment 
 
P.basic.person.name     = cs:string("My Name") 
P.basic:person.age      = 44 
P.basic.person.company  = cs:string("My Company") 
P.basic.person.address1 = cs:w_string("My Address") 
 
--// pointer dereferencing 
 
printf(1, "name     = %s\n", { P.basic:person.name.* }) 
printf(1, "age      = %d\n", { P.basic:person.age }) 
printf(1, "company  = %s\n", { P.basic:person.company.* }) 
printf(1, "address1 = %s\n", { P.basic:person.address1.wchars }) 
 
--// pointer address @ 
 
printf(1, "pointer address = %d\n", { @P.basic:person.name }) 
 
--// array of persons 
 
cs:struct D = cs:new(basic:vector[10, basic:person()]) 
 
/* 

   vector/array indexing 
 
   instance . [idx] 
*/ 
 
cs:struct E = cs:new(basic:vector[10]) 
 
for i = 0 to 9 do 
   --// implicit v member access 
   E.[i] = i 
   --// explicit v member access 
   E.v[i] = i 
end for