Change C<? mechanic

It's now a simple flag updated by the C< implementation. No more
routine pointer.

The goal is to avoid tons of "ok" during a LOAD operation.

blk/083

@@ -1,5 +1,6 @@
-C<?* is a pointer to a word being called by C<?. If 0 or 1,
-will return that value as-is.
+C<? is a flag indicating whether a character is waiting in the
+input stream. 1 means yes, 0 means no. It is the responsibility
+of C<* to update that flag.
 
 WORDBUF is the buffer used by WORD
 
@@ -12,5 +13,4 @@ jump to this address. If you use one of those slots for an
 interrupt, write a jump to the appropriate offset in that RAM
 location.
 
-
                                                         (cont.)

blk/398

@@ -2,7 +2,7 @@
   for an abort message )
 : (parse) (parsed) NOT IF ABORT THEN ;
 
-: C<? 0x06 RAM+ @ DUP 2 > IF EXECUTE THEN ( 06 == C<?* ) ;
+: C<? 0x06 RAM+ @ ;
 : C<
     0x08 RAM+ @  ( 08 == C<* override )
     DUP NOT IF DROP 0x0c RAM+ @ THEN  ( 0c == C<* )

forth/blk.fs

@@ -61,17 +61,21 @@
 ;
 
 : LOAD
-    ( save BLK>, C<* override and boot< ptr to RSP )
+    ( save restorable variables to RSP )
     BLK> @ >R
     0x08 RAM+ @ >R
-    0x2e RAM+ @ >R
+    0x06 RAM+ @ >R  ( C<? )
+    0x2e RAM+ @ >R  ( boot ptr )
     BLK@
     ( Point to beginning of BLK )
     BLK( 0x2e RAM+ !
     ( 08 == C<* override )
     ['] _ 0x08 RAM+ !
+    ( While we interpret, don't print "ok" after every word )
+    1 0x06 RAM+ !  ( 06 == C<? )
     INTERPRET
     R> 0x2e RAM+ !
+    R> 0x06 RAM+ !
     ( Before we restore C<* are we restoring it to "_"?
       if yes, it means we're in a nested LOAD which means we
       should also load back the saved BLK>. Otherwise, we can

forth/readln.fs

@@ -59,15 +59,18 @@
     LF IN( IN> !
 ;
 
-: RDLN<? IN> @ C@ ;
-
-( And finally, implement a replacement for the (c<) routine )
+( And finally, implement C<* )
 : RDLN<
-    RDLN<?                      ( c )
-    ( not EOL? good, inc and return )
-    DUP IF 1 IN> +! EXIT THEN   ( c )
-    ( EOL ? readline. we still return typed char though )
-    (rdln)                      ( c )
+    IN> @ C@
+    DUP IF
+        ( not EOL? good, inc and return )
+        1 IN> +!
+    ELSE
+        ( EOL ? readline. we still return null though )
+        (rdln)
+    THEN
+    ( update C<? flag )
+    IN> @ C@ 0 > 0x06 RAM+ !  ( 06 == C<? )
 ;
 
 ( Initializes the readln subsystem )
@@ -78,7 +81,7 @@
       the last typed 0x0a and one for the following NULL. )
     INBUFSZ 4 + ALLOT
     (infl)
-    ['] RDLN<? 0x06 RAM+ !
     ['] RDLN< 0x0c RAM+ !
+    1 0x06 RAM+ !  ( 06 == C<? )
 ;