X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flanguage%2Fcontrol%2Floop.c;h=dafc0ba8b4c2a534657fc51a85e6f18a08fe4613;hb=10b7dcaf6f48414b23ab99348835149419b3c971;hp=5c22f3ca57d377c48d2ff25b0b612ec9a7cda4ad;hpb=244ade48f9c233532cc535d3233fdef53bf9266b;p=pspp-builds.git

diff --git a/src/language/control/loop.c b/src/language/control/loop.c
index 5c22f3ca..dafc0ba8 100644
--- a/src/language/control/loop.c
+++ b/src/language/control/loop.c
@@ -1,6 +1,5 @@
 /* PSPP - computes sample statistics.
    Copyright (C) 1997-9, 2000 Free Software Foundation, Inc.
-   Written by Ben Pfaff <blp@gnu.org>.
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
@@ -87,46 +86,48 @@ static trns_proc_func loop_trns_proc, end_loop_trns_proc, break_trns_proc;
 static trns_free_func loop_trns_free;
 
 static struct loop_trns *create_loop_trns (struct dataset *);
-static bool parse_if_clause (struct loop_trns *, struct expression **);
-static bool parse_index_clause (struct loop_trns *, char index_var_name[]);
+static bool parse_if_clause (struct lexer *,
+                             struct loop_trns *, struct expression **);
+static bool parse_index_clause (struct dataset *, struct lexer *,
+                                struct loop_trns *, bool *created_index_var);
 static void close_loop (void *);
 
 /* LOOP. */
 
 /* Parses LOOP. */
 int
-cmd_loop (struct dataset *ds)
+cmd_loop (struct lexer *lexer, struct dataset *ds)
 {
   struct loop_trns *loop;
-  char index_var_name[LONG_NAME_LEN + 1];
+  bool created_index_var = false;
   bool ok = true;
 
   loop = create_loop_trns (ds);
-  while (token != '.' && ok) 
+  while (lex_token (lexer) != '.' && ok) 
     {
-      if (lex_match_id ("IF")) 
-        ok = parse_if_clause (loop, &loop->loop_condition);
+      if (lex_match_id (lexer, "IF")) 
+        ok = parse_if_clause (lexer, loop, &loop->loop_condition);
       else
-        ok = parse_index_clause (loop, index_var_name);
+        ok = parse_index_clause (ds, lexer, loop, &created_index_var);
     }
 
-  /* Find index variable and create if necessary. */
-  if (ok && index_var_name[0] != '\0')
+  /* Clean up if necessary. */
+  if (!ok) 
     {
-      loop->index_var = dict_lookup_var (dataset_dict (ds), index_var_name);
-      if (loop->index_var == NULL)
-        loop->index_var = dict_create_var (dataset_dict (ds), 
-					   index_var_name, 0);
+      loop->max_pass_count = 0; 
+      if (loop->index_var != NULL && created_index_var)
+        {
+          dict_delete_var (dataset_dict (ds), loop->index_var);
+          loop->index_var = NULL;
+        }
     }
-  
-  if (!ok)
-    loop->max_pass_count = 0;
-  return ok ? CMD_SUCCESS : CMD_FAILURE;
+
+  return ok ? CMD_SUCCESS : CMD_CASCADING_FAILURE;
 }
 
 /* Parses END LOOP. */
 int
-cmd_end_loop (struct dataset *ds)
+cmd_end_loop (struct lexer *lexer, struct dataset *ds)
 {
   struct loop_trns *loop;
   bool ok = true;
@@ -138,10 +139,10 @@ cmd_end_loop (struct dataset *ds)
   assert (loop->ds == ds);
   
   /* Parse syntax. */
-  if (lex_match_id ("IF"))
-    ok = parse_if_clause (loop, &loop->end_loop_condition);
+  if (lex_match_id (lexer, "IF"))
+    ok = parse_if_clause (lexer, loop, &loop->end_loop_condition);
   if (ok)
-    ok = lex_end_of_command () == CMD_SUCCESS;
+    ok = lex_end_of_command (lexer) == CMD_SUCCESS;
 
   if (!ok)
     loop->max_pass_count = 0;
@@ -153,7 +154,7 @@ cmd_end_loop (struct dataset *ds)
 
 /* Parses BREAK. */
 int
-cmd_break (struct dataset *ds)
+cmd_break (struct lexer *lexer, struct dataset *ds)
 {
   struct ctl_stmt *loop = ctl_stack_search (&loop_class);
   if (loop == NULL)
@@ -161,7 +162,7 @@ cmd_break (struct dataset *ds)
 
   add_transformation (ds, break_trns_proc, NULL, loop);
 
-  return lex_end_of_command ();
+  return lex_end_of_command (lexer);
 }
 
 /* Closes a LOOP construct by emitting the END LOOP
@@ -187,39 +188,64 @@ close_loop (void *loop_)
    resulting expression to *CONDITION.
    Returns true if successful, false on failure. */
 static bool
-parse_if_clause (struct loop_trns *loop, struct expression **condition) 
+parse_if_clause (struct lexer *lexer, 
+		 struct loop_trns *loop, struct expression **condition) 
 {
-  *condition = expr_parse_pool (loop->pool, loop->ds, EXPR_BOOLEAN);
+  if (*condition != NULL) 
+    {
+      lex_sbc_only_once ("IF");
+      return false;
+    }
+  
+  *condition = expr_parse_pool (lexer, loop->pool, loop->ds, EXPR_BOOLEAN);
   return *condition != NULL;
 }
 
 /* Parses an indexing clause into LOOP.
-   Stores the index variable's name in INDEX_VAR_NAME[].
+   Stores true in *CREATED_INDEX_VAR if the index clause created
+   a new variable, false otherwise.
    Returns true if successful, false on failure. */
 static bool
-parse_index_clause (struct loop_trns *loop, char index_var_name[]) 
+parse_index_clause (struct dataset *ds, struct lexer *lexer,
+                    struct loop_trns *loop, bool *created_index_var) 
 {
-  if (token != T_ID) 
+  if (loop->index_var != NULL) 
+    {
+      msg (SE, _("Only one index clause may be specified."));
+      return false;
+    }
+
+  if (lex_token (lexer) != T_ID) 
     {
-      lex_error (NULL);
+      lex_error (lexer, NULL);
       return false;
     }
-  strcpy (index_var_name, tokid);
-  lex_get ();
 
-  if (!lex_force_match ('='))
+  loop->index_var = dict_lookup_var (dataset_dict (ds), lex_tokid (lexer));
+  if (loop->index_var != NULL)
+    *created_index_var = false;
+  else
+    {
+      loop->index_var = dict_create_var_assert (dataset_dict (ds), 
+                                                lex_tokid (lexer), 0);
+      *created_index_var = true; 
+    }
+  lex_get (lexer);
+
+  if (!lex_force_match (lexer, '='))
     return false;
 
-  loop->first_expr = expr_parse_pool (loop->pool, loop->ds, EXPR_NUMBER);
+  loop->first_expr = expr_parse_pool (lexer, loop->pool, 
+				      loop->ds, EXPR_NUMBER);
   if (loop->first_expr == NULL)
     return false;
 
   for (;;)
     {
       struct expression **e;
-      if (lex_match (T_TO)) 
+      if (lex_match (lexer, T_TO)) 
         e = &loop->last_expr;
-      else if (lex_match (T_BY)) 
+      else if (lex_match (lexer, T_BY)) 
         e = &loop->by_expr;
       else
         break;
@@ -229,13 +255,13 @@ parse_index_clause (struct loop_trns *loop, char index_var_name[])
           lex_sbc_only_once (e == &loop->last_expr ? "TO" : "BY");
           return false;
         }
-      *e = expr_parse_pool (loop->pool, loop->ds, EXPR_NUMBER);
+      *e = expr_parse_pool (lexer, loop->pool, loop->ds, EXPR_NUMBER);
       if (*e == NULL)
         return false;
     }
   if (loop->last_expr == NULL) 
     {
-      lex_sbc_missing ("TO");
+      lex_sbc_missing (lexer, "TO");
       return false;
     }
   if (loop->by_expr == NULL)
@@ -292,7 +318,7 @@ loop_trns_proc (void *loop_, struct ccase *c, casenumber case_num)
 
       /* Even if the loop is never entered, set the index
          variable to the initial value. */
-      case_data_rw (c, loop->index_var->fv)->f = loop->cur;
+      case_data_rw (c, loop->index_var)->f = loop->cur;
 
       /* Throw out pathological cases. */
       if (!finite (loop->cur) || !finite (loop->by) || !finite (loop->last)
@@ -335,7 +361,7 @@ end_loop_trns_proc (void *loop_, struct ccase *c, casenumber case_num UNUSED)
   struct loop_trns *loop = loop_;
 
   if (loop->end_loop_condition != NULL
-      && expr_evaluate_num (loop->end_loop_condition, c, case_num) != 1.0)
+      && expr_evaluate_num (loop->end_loop_condition, c, case_num) != 0.0)
     goto break_out;
 
   /* MXLOOPS limiter. */
@@ -353,7 +379,7 @@ end_loop_trns_proc (void *loop_, struct ccase *c, casenumber case_num UNUSED)
       if ((loop->by > 0.0 && loop->cur > loop->last)
           || (loop->by < 0.0 && loop->cur < loop->last))
         goto break_out;
-      case_data_rw (c, loop->index_var->fv)->f = loop->cur;
+      case_data_rw (c, loop->index_var)->f = loop->cur;
     }
 
   if (loop->loop_condition != NULL