From: ian <ian>
Date: Sun, 8 Sep 2002 17:10:35 +0000 (+0000)
Subject: hbytes compare
X-Git-Tag: debian/1.1.1~159
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=chiark-tcl.git;a=commitdiff_plain;h=12cb589d468d6c93b04dfabe645ce761a81c5328

hbytes compare
---

diff --git a/base/chiark-tcl.h b/base/chiark-tcl.h
index 37697bb..4422d32 100644
--- a/base/chiark-tcl.h
+++ b/base/chiark-tcl.h
@@ -13,6 +13,13 @@
  *  hbytes chopto VAR NEWVARLENGTH               => suffix (removed from VAR)
  *                                                  (too short? error)
  *
+ *  hbytes compare A B
+ *      =>  -2   A is lexically earlier than B and not a prefix of B  (A<B)
+ *          -1   A is prefix of B but not equal                       (A<B)
+ *           0   A == B
+ *          +1   A is B plus a nonempty suffix (ie, A has B as a prefix)
+ *          +2   A is lexically later than B and does not have B as a prefix
+ *
  *  hbytes pkcs5 pa|ua VAR ALG                   => worked?  (always 1 for p)
  *  hbytes pkcs5 pn|un VAR BLOCKSIZE             => worked?  (always 1 for p)
  *  hbytes blockcipher d|e VAR ALG KEY MODE [IV] => IV
diff --git a/base/hook.c b/base/hook.c
index e53af08..8774f7b 100644
--- a/base/hook.c
+++ b/base/hook.c
@@ -177,6 +177,26 @@ int do_hbytes_zeroes(ClientData cd, Tcl_Interp *ip,
   return TCL_OK;
 }
 
+int do_hbytes_compare(ClientData cd, Tcl_Interp *ip,
+		      HBytes_Value a, HBytes_Value b, int *result) {
+  int al, bl, minl, r;
+
+  al= hbytes_len(&a);
+  bl= hbytes_len(&b);
+  minl= al<bl ? al : bl;
+
+  r= memcmp(hbytes_data(&a), hbytes_data(&b), minl);
+  
+  if (r<0) *result= -2;
+  else if (r>0) *result= +2;
+  else {
+    if (al<bl) *result= -1;
+    else if (al>bl) *result= +1;
+    else *result= 0;
+  }
+  return TCL_OK;
+}
+
 int do__hbytes(ClientData cd, Tcl_Interp *ip,
 	       const HBytes_SubCommand *subcmd,
 	       int objc, Tcl_Obj *const *objv) {
diff --git a/base/tables-examples.tct b/base/tables-examples.tct
index 37286ad..6bdc7ff 100644
--- a/base/tables-examples.tct
+++ b/base/tables-examples.tct
@@ -43,6 +43,10 @@ Table hbytes HBytes_SubCommand
 	length
 		v	hb
 		=>	int
+	compare
+		a	hb
+		b	hb
+		=>	int
  	prepend
  		v	hbv
  		str	...
diff --git a/hbytes/hbytes.h b/hbytes/hbytes.h
index 37697bb..4422d32 100644
--- a/hbytes/hbytes.h
+++ b/hbytes/hbytes.h
@@ -13,6 +13,13 @@
  *  hbytes chopto VAR NEWVARLENGTH               => suffix (removed from VAR)
  *                                                  (too short? error)
  *
+ *  hbytes compare A B
+ *      =>  -2   A is lexically earlier than B and not a prefix of B  (A<B)
+ *          -1   A is prefix of B but not equal                       (A<B)
+ *           0   A == B
+ *          +1   A is B plus a nonempty suffix (ie, A has B as a prefix)
+ *          +2   A is lexically later than B and does not have B as a prefix
+ *
  *  hbytes pkcs5 pa|ua VAR ALG                   => worked?  (always 1 for p)
  *  hbytes pkcs5 pn|un VAR BLOCKSIZE             => worked?  (always 1 for p)
  *  hbytes blockcipher d|e VAR ALG KEY MODE [IV] => IV
diff --git a/hbytes/hook.c b/hbytes/hook.c
index e53af08..8774f7b 100644
--- a/hbytes/hook.c
+++ b/hbytes/hook.c
@@ -177,6 +177,26 @@ int do_hbytes_zeroes(ClientData cd, Tcl_Interp *ip,
   return TCL_OK;
 }
 
+int do_hbytes_compare(ClientData cd, Tcl_Interp *ip,
+		      HBytes_Value a, HBytes_Value b, int *result) {
+  int al, bl, minl, r;
+
+  al= hbytes_len(&a);
+  bl= hbytes_len(&b);
+  minl= al<bl ? al : bl;
+
+  r= memcmp(hbytes_data(&a), hbytes_data(&b), minl);
+  
+  if (r<0) *result= -2;
+  else if (r>0) *result= +2;
+  else {
+    if (al<bl) *result= -1;
+    else if (al>bl) *result= +1;
+    else *result= 0;
+  }
+  return TCL_OK;
+}
+
 int do__hbytes(ClientData cd, Tcl_Interp *ip,
 	       const HBytes_SubCommand *subcmd,
 	       int objc, Tcl_Obj *const *objv) {