Re: Attempting to unbox struct fields

["Thompson, David" <dthompson2@worcester.edu>]

[-- Attachment #1: Type: text/plain, Size: 171 bytes --]

Here's a patch I came up with to enable (and fix where necessary) the
support for signed integer and double struct fields.  Am I on the
right track here?

Thanks,

- Dave

[-- Attachment #2: 0001-struct-Add-support-for-unboxed-signed-integers-and-d.patch --]
[-- Type: text/x-diff, Size: 2751 bytes --]

From 8bde5c7018fde91cc7140777107bacfb3febb170 Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Sun, 28 Feb 2016 16:11:35 -0500
Subject: [PATCH] struct: Add support for unboxed signed integers and doubles.

* libguile/struct.c (scm_make_struct_layout): Enable 'i' and 'd' cases.
(scm_is_valid_vtable_layout): Add 'i' and 'd' cases.
(scm_struct_init): Initialize signed integer and double fields.
(scm_struct_ref): Enable 'i' and 'd' cases.  Update 'd' case to use
scm_from_double instead of obsolete scm_make_real.
(scm_struct_set_x): Enable 'i' and 'd' cases.  Update 'd' case to use
SCM_NUM2DOUBLE instead of obsolete scm_num2dbl.
---
 libguile/struct.c | 32 ++++++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/libguile/struct.c b/libguile/struct.c
index 8bfbcf4..c50019c 100644
--- a/libguile/struct.c
+++ b/libguile/struct.c
@@ -100,10 +100,8 @@ SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0,
 	  {
 	  case 'u':
 	  case 'p':
-#if 0
 	  case 'i':
 	  case 'd':
-#endif
 	  case 's':
 	    break;
 	  default:
@@ -219,6 +217,8 @@ scm_is_valid_vtable_layout (SCM layout)
     switch (c_layout[n])
       {
       case 'u':
+      case 'i':
+      case 'd':
       case 'p':
       case 's':
         switch (c_layout[n+1])
@@ -360,6 +360,26 @@ scm_struct_init (SCM handle, SCM layout, size_t n_tail,
 		}
 	      break;
 
+            case 'i':
+	      if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
+		*mem = 0;
+	      else
+		{
+		  *mem = scm_to_long (SCM_PACK (inits[inits_idx]));
+		  inits_idx++;
+		}
+	      break;
+
+            case 'd':
+	      if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
+		*mem = 0.0;
+	      else
+		{
+		  *((double *) mem) = scm_to_double (SCM_PACK (inits[inits_idx]));
+		  inits_idx++;
+		}
+	      break;
+
 	    case 'p':
 	      if ((prot != 'r' && prot != 'w') || inits_idx == n_inits)
 		*mem = SCM_UNPACK (SCM_BOOL_F);
@@ -761,15 +781,13 @@ SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0,
 	  answer = scm_from_ulong (data[p]);
 	  break;
 
-#if 0
 	case 'i':
 	  answer = scm_from_long (data[p]);
 	  break;
 
 	case 'd':
-	  answer = scm_make_real (*((double *)&(data[p])));
+	  answer = scm_from_double (*((double *)&(data[p])));
 	  break;
-#endif
 
 	case 's':
 	case 'p':
@@ -844,15 +862,13 @@ SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0,
 	  data[p] = SCM_NUM2ULONG (3, val);
 	  break;
 
-#if 0
 	case 'i':
 	  data[p] = SCM_NUM2LONG (3, val);
 	  break;
 
 	case 'd':
-	  *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3);
+	  *((double *)&(data[p])) = SCM_NUM2DOUBLE (3, val);
 	  break;
-#endif
 
 	case 'p':
 	  data[p] = SCM_UNPACK (val);
-- 
2.6.3