Index: trunk/src_plugins/order/constraint.c
===================================================================
--- trunk/src_plugins/order/constraint.c	(revision 36873)
+++ trunk/src_plugins/order/constraint.c	(revision 36874)
@@ -322,7 +322,7 @@
 
 			pcb_ordc_exec_node(ctx, &a, node->ch_first);
 			pcb_ordc_exec_node(ctx, &b, node->ch_first->next);
-			ctx->error_cb(ctx, a.val.s, b.val.s); /* no need to convert; grammar ensures static strings */
+			ctx->error_cb(ctx, a.val.s, b.val.s, &node->ch_first->ucache); /* no need to convert; grammar ensures static strings */
 			val_free(&a);
 			val_free(&b);
 			break;
@@ -351,7 +351,7 @@
 				break; /* everything evaluates to error */
 			}
 
-			ctx->var_cb(ctx, dst, node->val.s); /* no need to convert; grammar ensures static string */
+			ctx->var_cb(ctx, dst, node->val.s, &node->ucache); /* no need to convert; grammar ensures static string */
 			if (dst->type == PCB_ORDC_VERR)
 				rnd_message(RND_MSG_ERROR, "order: constraint script error: no such variable '%s'\n", node->val.s);
 			break;
Index: trunk/src_plugins/order/constraint.h
===================================================================
--- trunk/src_plugins/order/constraint.h	(revision 36873)
+++ trunk/src_plugins/order/constraint.h	(revision 36874)
@@ -48,6 +48,7 @@
 		double d;
 		char *s;
 	} val;
+	void *ucache;
 	pcb_ordc_node_t *ch_first, *next;
 };
 
@@ -67,8 +68,14 @@
 	pcb_ordc_node_t *root;
 
 	/*** application provided callbacks ***/
-	void (*error_cb)(pcb_ordc_ctx_t *ctx, const char *varname, const char *msg);
-	void (*var_cb)(pcb_ordc_ctx_t *ctx, pcb_ordc_val_t *dst, const char *varname);
+	/* note:  ucache is a (void *) stored in the node triggering the call; the
+	   caller may cache varname resolution there */
+
+	/* called on error() from the script */
+	void (*error_cb)(pcb_ordc_ctx_t *ctx, const char *varname, const char *msg, void **ucache);
+
+	/* called on $var from the script, should load dst->type and dst->val */
+	void (*var_cb)(pcb_ordc_ctx_t *ctx, pcb_ordc_val_t *dst, const char *varname, void **ucache);
 };
 
 int pcb_ordc_parse_str(pcb_ordc_ctx_t *ctx, const char *script);