(read1): New argument for returning out-of-band data, obviating the need for

Lisp_Internal datatype.
(read0, read1, read_list): Use that new calling sequence.

diff --git a/src/lread.c b/src/lread.c
index dce5912d03d0b31eecbf7e91354e7616e6ff8495..23885cc8ad330a64ecb25516d7b28e741e3f869a 100644 (file)
--- a/src/lread.c
+++ b/src/lread.c
@@ -929,8 +929,8 @@ START and END optionally delimit a substring of STRING from which to read;\n\
   return Fcons (tem, make_number (read_from_string_index));
 }
 \f
-/* Use this for recursive reads, in contexts where internal tokens are not allowed. */
-
+/* Use this for recursive reads, in contexts where internal tokens
+   are not allowed. */
 static Lisp_Object
 read0 (readcharfun)
      Lisp_Object readcharfun;
@@ -938,12 +938,9 @@ read0 (readcharfun)
   register Lisp_Object val;
   char c;
 
-  val = read1 (readcharfun);
-  if (INTERNALP (val))
-    {
-      c = XINT (val);
-      return Fsignal (Qinvalid_read_syntax, Fcons (make_string (&c, 1), Qnil));
-    }
+  val = read1 (readcharfun, &c);
+  if (c)
+    Fsignal (Qinvalid_read_syntax, Fcons (make_string (&c, 1), Qnil));
 
   return val;
 }
@@ -1106,11 +1103,16 @@ read_escape (readcharfun)
     }
 }
 
+/* If the next token is ')' or ']' or '.', we store that character
+   in *PCH and the return value is not interesting.  Else, we store
+   zero in *PCH and we read and return one lisp object.  */
 static Lisp_Object
-read1 (readcharfun)
+read1 (readcharfun, pch)
      register Lisp_Object readcharfun;
+     char *pch;
 {
   register int c;
+  *pch = 0;
 
  retry:
 
@@ -1128,9 +1130,8 @@ read1 (readcharfun)
     case ')':
     case ']':
       {
-       register Lisp_Object val;
-       XSETINTERNAL (val, c);
-       return val;
+       *pch = c;
+       return Qnil;
       }
 
     case '#':
@@ -1149,10 +1150,11 @@ read1 (readcharfun)
        {
          Lisp_Object tmp;
          struct gcpro gcpro1;
+         char ch;
 
          /* Read the string itself.  */
-         tmp = read1 (readcharfun);
-         if (!STRINGP (tmp))
+         tmp = read1 (readcharfun, &ch);
+         if (ch != 0 || !STRINGP (tmp))
            Fsignal (Qinvalid_read_syntax, Fcons (make_string ("#", 1), Qnil));
          GCPRO1 (tmp);
          /* Read the intervals and their properties.  */
@@ -1160,22 +1162,17 @@ read1 (readcharfun)
            {
              Lisp_Object beg, end, plist;
 
-             beg = read1 (readcharfun);
-             if (INTERNALP (beg))
-               {
-                 if (XINT (beg) == ')')
-                   break;
-                 Fsignal (Qinvalid_read_syntax, Fcons (make_string ("invalid string property list", 28), Qnil));
-               }
-             end = read1 (readcharfun);
-             if (INTERNALP (end))
-               Fsignal (Qinvalid_read_syntax,
-                        Fcons (make_string ("invalid string property list", 28), Qnil));
-               
-             plist = read1 (readcharfun);
-             if (INTERNALP (plist))
+             beg = read1 (readcharfun, &ch);
+             if (ch == ')')
+               break;
+             if (ch == 0)
+               end = read1 (readcharfun, &ch);
+             if (ch == 0)
+               plist = read1 (readcharfun, &ch);
+             if (ch)
                Fsignal (Qinvalid_read_syntax,
-                        Fcons (make_string ("invalid string property list", 28), Qnil));
+                        Fcons (build_string ("invalid string property list"),
+                               Qnil));
              Fset_text_properties (beg, end, plist, tmp);
            }
          UNGCPRO;
@@ -1276,9 +1273,8 @@ read1 (readcharfun)
        if (! isdigit (next_char))
 #endif
          {
-           register Lisp_Object val;
-           XSETINTERNAL (val, c);
-           return val;
+           *pch = c;
+           return Qnil;
          }
 
        /* Otherwise, we fall through!  Note that the atom-reading loop
@@ -1477,29 +1473,30 @@ read_list (flag, readcharfun)
 
   while (1)
     {
+      char ch;
       GCPRO2 (val, tail);
-      elt = read1 (readcharfun);
+      elt = read1 (readcharfun, &ch);
       UNGCPRO;
-      if (INTERNALP (elt))
+      if (ch)
        {
          if (flag > 0)
            {
-             if (XINT (elt) == ']')
+             if (ch == ']')
                return val;
-             return Fsignal (Qinvalid_read_syntax, Fcons (make_string (") or . in a vector", 18), Qnil));
+             Fsignal (Qinvalid_read_syntax, Fcons (make_string (") or . in a vector", 18), Qnil));
            }
-         if (XINT (elt) == ')')
+         if (ch == ')')
            return val;
-         if (XINT (elt) == '.')
+         if (ch == '.')
            {
              GCPRO2 (val, tail);
              if (!NILP (tail))
                XCONS (tail)->cdr = read0 (readcharfun);
              else
                val = read0 (readcharfun);
-             elt = read1 (readcharfun);
+             read1 (readcharfun, &ch);
              UNGCPRO;
-             if (INTERNALP (elt) && XINT (elt) == ')')
+             if (ch == ')')
                return val;
              return Fsignal (Qinvalid_read_syntax, Fcons (make_string (". in wrong context", 18), Qnil));
            }