[wip] wrappers for full leopard api

Needs to be proved out by doing a port of leopard's benchmark tool to Nim,
i.e. there are still some questions re: parameter types

dagger/leopard.nim

@@ -1,5 +1,32 @@
-const header = "leopard.h"
+type
+  LeopardResult* {.pure.} = enum
+    Leopard_CallInitialize = -7.cint
+    Leopard_Platform       = -6.cint
+    Leopard_InvalidInput   = -5.cint
+    Leopard_InvalidCounts  = -4.cint
+    Leopard_InvalidSize    = -3.cint
+    Leopard_TooMuchData    = -2.cint
+    Leopard_NeedMoreData   = -1.cint
+    Leopard_Success        =  0.cint
+
+const
+  header = "leopard.h"
 
 {.pragma: leo, cdecl, header: header, importCpp.}
 
 proc leo_init*(): cint {.leo.}
+
+func leo_result_string*(res: LeopardResult): cstring {.leo.}
+
+func leo_encode_work_count*(original_count, recovery_count: cuint): cuint
+  {.leo.}
+
+proc leo_encode*(buffer_bytes: uint64, original_count, recovery_count,
+  work_count: cuint, original_data, work_data: pointer): LeopardResult {.leo.}
+
+func leo_decode_work_count*(original_count, recovery_count: cuint): cuint
+  {.leo.}
+
+proc leo_decode*(buffer_bytes: uint64, original_count, recovery_count,
+  work_count: cuint, original_data, recovery_data, work_data: pointer):
+  LeopardResult {.leo.}

tests/dagger/testleopard.nim

@@ -2,4 +2,5 @@ import pkg/dagger/leopard
 
 let lin = leo_init()
 
+echo ""
 echo "leo_init() return code: " & $lin