Move all command implementations into a single 'commands' directory.

[pspp] / src / language / commands / sort-criteria.c

diff --git a/src/language/commands/sort-criteria.c b/src/language/commands/sort-criteria.c
new file mode 100644 (file)
index 0000000..4f33fb3
--- /dev/null
+++ b/src/language/commands/sort-criteria.c
@@ -0,0 +1,107 @@
+/* PSPP - a program for statistical analysis.
+   Copyright (C) 1997-9, 2000, 2006, 2010, 2011 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+#include "language/commands/sort-criteria.h"
+
+#include <stdlib.h>
+
+#include "data/dictionary.h"
+#include "data/subcase.h"
+#include "data/variable.h"
+#include "language/lexer/lexer.h"
+#include "language/lexer/variable-parser.h"
+#include "libpspp/message.h"
+
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
+/* Parses a list of sort fields and appends them to ORDERING,
+   which the caller must already have initialized.
+   Returns true if successful, false on error.
+   If SAW_DIRECTION is nonnull, sets *SAW_DIRECTION to true if at
+   least one parenthesized sort direction was specified, false
+   otherwise. */
+bool
+parse_sort_criteria (struct lexer *lexer, const struct dictionary *dict,
+                     struct subcase *ordering,
+                     const struct variable ***vars, bool *saw_direction)
+{
+  const struct variable **local_vars = NULL;
+  size_t n_vars = 0;
+
+  if (vars == NULL)
+    vars = &local_vars;
+  *vars = NULL;
+
+  if (saw_direction != NULL)
+    *saw_direction = false;
+
+  int start_ofs = lex_ofs (lexer);
+  do
+    {
+      size_t prev_n_vars = n_vars;
+
+      /* Variables. */
+      if (!parse_variables_const (lexer, dict, vars, &n_vars,
+                                  PV_APPEND | PV_DUPLICATE | PV_NO_SCRATCH))
+        goto error;
+
+      /* Sort direction. */
+      enum subcase_direction direction;
+      if (lex_match (lexer, T_LPAREN))
+       {
+         if (lex_match_id (lexer, "D") || lex_match_id (lexer, "DOWN"))
+           direction = SC_DESCEND;
+         else if (lex_match_id (lexer, "A") || lex_match_id (lexer, "UP"))
+            direction = SC_ASCEND;
+          else
+           {
+              lex_error_expecting (lexer, "A", "D");
+              goto error;
+           }
+         if (!lex_force_match (lexer, T_RPAREN))
+            goto error;
+          if (saw_direction != NULL)
+            *saw_direction = true;
+       }
+      else
+        direction = SC_ASCEND;
+
+      for (size_t i = prev_n_vars; i < n_vars; i++)
+        {
+          const struct variable *var = (*vars)[i];
+          if (!subcase_add_var (ordering, var, direction))
+            lex_ofs_msg (lexer, SW, start_ofs, lex_ofs (lexer) - 1,
+                         _("Variable %s specified twice in sort criteria."),
+                         var_get_name (var));
+        }
+    }
+  while (lex_token (lexer) == T_ID
+         && dict_lookup_var (dict, lex_tokcstr (lexer)) != NULL);
+
+  free (local_vars);
+  return true;
+
+error:
+  subcase_uninit (ordering);
+  subcase_init_empty (ordering);
+  free (local_vars);
+  if (vars)
+    *vars = NULL;
+  return false;
+}