hbytes range

[chiark-tcl.git] / hbytes / hook.c

diff --git a/hbytes/hook.c b/hbytes/hook.c
index 8774f7b6a3fb174a5588305052cb65dc1f8dff93..0efc5f1607aabb7539727d681662ce29c46cc089 100644 (file)
--- a/hbytes/hook.c
+++ b/hbytes/hook.c
@@ -197,6 +197,21 @@ int do_hbytes_compare(ClientData cd, Tcl_Interp *ip,
   return TCL_OK;
 }
 
+int do_hbytes_range(ClientData cd, Tcl_Interp *ip,
+                   HBytes_Value v, int start, int size,
+                   HBytes_Value *result) {
+  const Byte *data;
+  int l;
+
+  l= hbytes_len(&v);
+  if (start<0 || size<0 || l<start+size)
+    return staticerr(ip, "hbytes range subscripts out of range");
+
+  data= hbytes_data(&v);
+  hbytes_array(result, data+start, size);
+  return TCL_OK;
+}
+  
 int do__hbytes(ClientData cd, Tcl_Interp *ip,
               const HBytes_SubCommand *subcmd,
               int objc, Tcl_Obj *const *objv) {