altos/lisp: Make read() return eof atom on end of file

[fw/altos] / src / lisp / ao_lisp_read.c

diff --git a/src/lisp/ao_lisp_read.c b/src/lisp/ao_lisp_read.c
index 3a2ef7f1f15cef109e81589a1adcd6e33132f61a..7a5751cef0315a7ec4662b3a49ab6ab0490a6592 100644 (file)
--- a/src/lisp/ao_lisp_read.c
+++ b/src/lisp/ao_lisp_read.c
@@ -12,6 +12,7 @@
  * General Public License for more details.
  */
 
+#define DBG_EVAL 0
 #include "ao_lisp.h"
 #include "ao_lisp_read.h"
 
@@ -270,7 +271,7 @@ lex(void)
        for (;;) {
                c = lexc();
                if (lex_class & ENDOFFILE)
-                       return AO_LISP_NIL;
+                       return END;
 
                if (lex_class & WHITE)
                        continue;
@@ -278,7 +279,7 @@ lex(void)
                if (lex_class & COMMENT) {
                        while ((c = lexc()) != '\n') {
                                if (lex_class & ENDOFFILE)
-                                       return AO_LISP_NIL;
+                                       return END;
                        }
                        continue;
                }
@@ -364,6 +365,8 @@ static struct ao_lisp_cons  *read_stack;
 static int
 push_read_stack(int cons, int in_quote)
 {
+       DBGI("push read stack %p %d\n", read_cons, in_quote);
+       DBG_IN();
        if (cons) {
                read_stack = ao_lisp_cons_cons(ao_lisp_cons_poly(read_cons),
                                               ao_lisp_cons_cons(ao_lisp_int_poly(in_quote),
@@ -394,6 +397,8 @@ pop_read_stack(int cons)
                read_cons_tail = 0;
                read_stack = 0;
        }
+       DBG_OUT();
+       DBGI("pop read stack %p %d\n", read_cons, in_quote);
        return in_quote;
 }
 
@@ -413,6 +418,7 @@ ao_lisp_read(void)
                been_here = 1;
        }
        parse_token = lex();
+       DBGI("token %d (%s)\n", parse_token, token_string);
 
        cons = 0;
        in_quote = 0;
@@ -424,12 +430,15 @@ ao_lisp_read(void)
                        cons++;
                        in_quote = 0;
                        parse_token = lex();
+                       DBGI("token %d (%s)\n", parse_token, token_string);
                }
 
                switch (parse_token) {
-               case ENDOFFILE:
+               case END:
                default:
-                       v = AO_LISP_NIL;
+                       if (cons)
+                               ao_lisp_error(AO_LISP_EOF, "unexpected end of file");
+                       return _ao_lisp_atom_eof;
                        break;
                case NAME:
                        atom = ao_lisp_atom_intern(token_string);
@@ -490,6 +499,7 @@ ao_lisp_read(void)
                }
 
                parse_token = lex();
+               DBGI("token %d (%s)\n", parse_token, token_string);
        }
        return v;
 }