Index: class.c
==================================================================
--- class.c
+++ class.c
@@ -749,22 +749,22 @@
         case MAC_ADD:
           n=0;
           for(;;) {
             nxttok();
             if(tokent==TF_MACRO+TF_CLOSE) break;
-            if(tokent!=TF_INT) ParseError("Number expected\n");
+            if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
             n+=tokenv;
           }
           tokent=TF_INT;
           tokenv=n;
           break;
         case MAC_SUB:
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           n=tokenv;
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           n-=tokenv;
           nxttok();
           if(tokent!=TF_MACRO+TF_CLOSE) ParseError("Too many macro arguments\n");
           tokent=TF_INT;
           tokenv=n;
@@ -772,35 +772,35 @@
         case MAC_MUL:
           n=1;
           for(;;) {
             nxttok();
             if(tokent==TF_MACRO+TF_CLOSE) break;
-            if(tokent!=TF_INT) ParseError("Number expected\n");
+            if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
             n*=tokenv;
           }
           tokent=TF_INT;
           tokenv=n;
           break;
         case MAC_DIV:
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           n=tokenv;
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           if(!tokenv) ParseError("Division by zero\n");
           n/=tokenv;
           nxttok();
           if(tokent!=TF_MACRO+TF_CLOSE) ParseError("Too many macro arguments\n");
           tokent=TF_INT;
           tokenv=n;
           break;
         case MAC_MOD:
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           n=tokenv;
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           if(!tokenv) ParseError("Division by zero\n");
           n%=tokenv;
           nxttok();
           if(tokent!=TF_MACRO+TF_CLOSE) ParseError("Too many macro arguments\n");
           tokent=TF_INT;
@@ -809,11 +809,11 @@
         case MAC_BAND:
           n=-1;
           for(;;) {
             nxttok();
             if(tokent==TF_MACRO+TF_CLOSE) break;
-            if(tokent!=TF_INT) ParseError("Number expected\n");
+            if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
             n&=tokenv;
           }
           tokent=TF_INT;
           tokenv=n;
           break;
@@ -820,11 +820,11 @@
         case MAC_BOR:
           n=0;
           for(;;) {
             nxttok();
             if(tokent==TF_MACRO+TF_CLOSE) break;
-            if(tokent!=TF_INT) ParseError("Number expected\n");
+            if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
             n|=tokenv;
           }
           tokent=TF_INT;
           tokenv=n;
           break;
@@ -831,19 +831,19 @@
         case MAC_BXOR:
           n=0;
           for(;;) {
             nxttok();
             if(tokent==TF_MACRO+TF_CLOSE) break;
-            if(tokent!=TF_INT) ParseError("Number expected\n");
+            if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
             n^=tokenv;
           }
           tokent=TF_INT;
           tokenv=n;
           break;
         case MAC_BNOT:
           nxttok();
-          if(tokent!=TF_INT) ParseError("Number expected\n");
+          if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
           n=~tokenv;
           nxttok();
           if(tokent!=TF_MACRO+TF_CLOSE) ParseError("Too many macro arguments\n");
           tokent=TF_INT;
           tokenv=n;
@@ -875,11 +875,11 @@
         case MAC_BIT:
           n=0;
           for(;;) {
             nxttok();
             if(tokent==TF_MACRO+TF_CLOSE) break;
-            if(tokent!=TF_INT) ParseError("Number expected\n");
+            if(tokent!=TF_INT && tokent!=TF_NAME+TF_DIR && tokent!=TF_NAME+TF_KEY) ParseError("Number expected\n");
             if(tokenv<32) n|=1<<tokenv;
           }
           tokent=TF_INT;
           tokenv=n;
           break;
@@ -1050,10 +1050,11 @@
           if(tokent==TF_INT) {
             if(!macstack) ParseError("Empty macro stack\n");
             n=tokenv-1;
             nxttok();
             if(n<0 || macstack->n<=n || !macstack->args[n]) ParseError("Cannot edit nonexistent argument %u\n",n+1);
+            if(macstack->args[n]->t&(TF_MACRO|TF_EOF)) ParseError("Invalid edit token\n");
             macstack->args[n]->t=tokent;
             macstack->args[n]->v=tokenv;
             macstack->args[n]->str=0;
             if(*tokenstr) {
               macstack->args[n]->str=strdup(tokenstr);

Index: class.doc
==================================================================
--- class.doc
+++ class.doc
@@ -209,10 +209,13 @@
   Modulo.
 
 {version <number>}
   Expands into nothing. The number must be zero, otherwise it is an error.
   Future versions of Free Hero Mesh may change this.
+
+All arithmetic/bitwise macros also allow their arguments to be directions
+and keys, in which case they are treated as the corresponding numbers.
 
 It is possible to implement a tag system in this preprocessor, which makes
 it Turing complete. For example:
 
   {define "skip" {call \2}}