1 /* PSPP - computes sample statistics.
2 Copyright (C) 1997-9, 2000 Free Software Foundation, Inc.
3 Written by Ben Pfaff <blp@gnu.org>.
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 This program is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 #include <sys/types.h>
25 #include <libpspp/alloc.h>
26 #include <language/command.h>
27 #include <libpspp/message.h>
28 #include <language/lexer/lexer.h>
29 #include <language/lexer/variable-parser.h>
30 #include <data/settings.h>
31 #include <data/variable.h>
32 #include "sort-criteria.h"
33 #include <math/sort.h>
36 #define _(msgid) gettext (msgid)
38 static bool is_terminator(int tok, const int *terminators);
41 /* Parses a list of sort keys and returns a struct sort_criteria
42 based on it. Returns a null pointer on error.
43 If SAW_DIRECTION is nonnull, sets *SAW_DIRECTION to true if at
44 least one parenthesized sort direction was specified, false
46 If TERMINATORS is non-null, then it must be a pointer to a
47 null terminated list of tokens, in addition to the defaults,
48 which are to be considered terminators of the clause being parsed.
49 The default terminators are '/' and '.'
52 struct sort_criteria *
53 sort_parse_criteria (struct lexer *lexer, const struct dictionary *dict,
54 struct variable ***vars, size_t *var_cnt,
56 const int *terminators
59 struct sort_criteria *criteria;
60 struct variable **local_vars = NULL;
63 assert ((vars == NULL) == (var_cnt == NULL));
67 var_cnt = &local_var_cnt;
70 criteria = xmalloc (sizeof *criteria);
71 criteria->crits = NULL;
72 criteria->crit_cnt = 0;
76 if (saw_direction != NULL)
77 *saw_direction = false;
81 size_t prev_var_cnt = *var_cnt;
82 enum sort_direction direction;
85 if (!parse_variables (lexer, dict, vars, var_cnt,
86 PV_NO_DUPLICATE | PV_APPEND | PV_NO_SCRATCH))
90 if (lex_match (lexer, '('))
92 if (lex_match_id (lexer, "D") || lex_match_id (lexer, "DOWN"))
93 direction = SRT_DESCEND;
94 else if (lex_match_id (lexer, "A") || lex_match_id (lexer, "UP"))
95 direction = SRT_ASCEND;
98 msg (SE, _("`A' or `D' expected inside parentheses."));
101 if (!lex_match (lexer, ')'))
103 msg (SE, _("`)' expected."));
106 if (saw_direction != NULL)
107 *saw_direction = true;
110 direction = SRT_ASCEND;
112 criteria->crits = xnrealloc (criteria->crits,
113 *var_cnt, sizeof *criteria->crits);
114 criteria->crit_cnt = *var_cnt;
115 for (; prev_var_cnt < criteria->crit_cnt; prev_var_cnt++)
117 struct sort_criterion *c = &criteria->crits[prev_var_cnt];
118 c->fv = (*vars)[prev_var_cnt]->fv;
119 c->width = (*vars)[prev_var_cnt]->width;
123 while (lex_token (lexer) != '.' && lex_token (lexer) != '/' && !is_terminator(lex_token (lexer), terminators));
130 sort_destroy_criteria (criteria);
134 /* Return TRUE if TOK is a member of the list of TERMINATORS.
137 is_terminator(int tok, const int *terminators)
139 if (terminators == NULL )
142 while ( *terminators)
144 if (tok == *terminators++)
153 /* Destroys a SORT CASES program. */
155 sort_destroy_criteria (struct sort_criteria *criteria)
157 if (criteria != NULL)
159 free (criteria->crits);