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
24 #include <data/case.h>
25 #include <data/dictionary.h>
26 #include <data/procedure.h>
27 #include <data/transformations.h>
28 #include <data/variable.h>
29 #include <language/command.h>
30 #include <language/expressions/public.h>
31 #include <language/lexer/lexer.h>
32 #include <libpspp/alloc.h>
33 #include <libpspp/message.h>
34 #include <libpspp/message.h>
35 #include <libpspp/misc.h>
36 #include <libpspp/str.h>
39 #define _(msgid) gettext (msgid)
44 /* Target of a COMPUTE or IF assignment, either a variable or a
46 static struct lvalue *lvalue_parse (void);
47 static int lvalue_get_type (const struct lvalue *);
48 static bool lvalue_is_vector (const struct lvalue *);
49 static void lvalue_finalize (struct lvalue *,
50 struct compute_trns *);
51 static void lvalue_destroy (struct lvalue *);
53 /* COMPUTE and IF transformation. */
56 /* Test expression (IF only). */
57 struct expression *test; /* Test expression. */
59 /* Variable lvalue, if variable != NULL. */
60 struct variable *variable; /* Destination variable, if any. */
61 int fv; /* `value' index of destination variable. */
62 int width; /* Lvalue string width; 0=numeric. */
64 /* Vector lvalue, if vector != NULL. */
65 const struct vector *vector; /* Destination vector, if any. */
66 struct expression *element; /* Destination vector element expr. */
69 struct expression *rvalue; /* Rvalue expression. */
72 static struct expression *parse_rvalue (const struct lvalue *);
73 static struct compute_trns *compute_trns_create (void);
74 static trns_proc_func *get_proc_func (const struct lvalue *);
75 static trns_free_func compute_trns_free;
82 struct lvalue *lvalue = NULL;
83 struct compute_trns *compute = NULL;
85 compute = compute_trns_create ();
87 lvalue = lvalue_parse ();
91 if (!lex_force_match ('='))
93 compute->rvalue = parse_rvalue (lvalue);
94 if (compute->rvalue == NULL)
97 add_transformation (current_dataset,
98 get_proc_func (lvalue), compute_trns_free, compute);
100 lvalue_finalize (lvalue, compute);
102 return lex_end_of_command ();
105 lvalue_destroy (lvalue);
106 compute_trns_free (compute);
107 return CMD_CASCADING_FAILURE;
110 /* Transformation functions. */
112 /* Handle COMPUTE or IF with numeric target variable. */
114 compute_num (void *compute_, struct ccase *c, casenum_t case_num)
116 struct compute_trns *compute = compute_;
118 if (compute->test == NULL
119 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
120 case_data_rw (c, compute->fv)->f = expr_evaluate_num (compute->rvalue, c,
123 return TRNS_CONTINUE;
126 /* Handle COMPUTE or IF with numeric vector element target
129 compute_num_vec (void *compute_, struct ccase *c, casenum_t case_num)
131 struct compute_trns *compute = compute_;
133 if (compute->test == NULL
134 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
136 double index; /* Index into the vector. */
137 int rindx; /* Rounded index value. */
139 index = expr_evaluate_num (compute->element, c, case_num);
140 rindx = floor (index + EPSILON);
141 if (index == SYSMIS || rindx < 1 || rindx > compute->vector->cnt)
144 msg (SW, _("When executing COMPUTE: SYSMIS is not a valid value as "
145 "an index into vector %s."), compute->vector->name);
147 msg (SW, _("When executing COMPUTE: %g is not a valid value as "
148 "an index into vector %s."),
149 index, compute->vector->name);
150 return TRNS_CONTINUE;
152 case_data_rw (c, compute->vector->var[rindx - 1]->fv)->f
153 = expr_evaluate_num (compute->rvalue, c, case_num);
156 return TRNS_CONTINUE;
159 /* Handle COMPUTE or IF with string target variable. */
161 compute_str (void *compute_, struct ccase *c, casenum_t case_num)
163 struct compute_trns *compute = compute_;
165 if (compute->test == NULL
166 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
167 expr_evaluate_str (compute->rvalue, c, case_num,
168 case_data_rw (c, compute->fv)->s, compute->width);
170 return TRNS_CONTINUE;
173 /* Handle COMPUTE or IF with string vector element target
176 compute_str_vec (void *compute_, struct ccase *c, casenum_t case_num)
178 struct compute_trns *compute = compute_;
180 if (compute->test == NULL
181 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
183 double index; /* Index into the vector. */
184 int rindx; /* Rounded index value. */
185 struct variable *vr; /* Variable reference by indexed vector. */
187 index = expr_evaluate_num (compute->element, c, case_num);
188 rindx = floor (index + EPSILON);
191 msg (SW, _("When executing COMPUTE: SYSMIS is not a valid "
192 "value as an index into vector %s."),
193 compute->vector->name);
194 return TRNS_CONTINUE;
196 else if (rindx < 1 || rindx > compute->vector->cnt)
198 msg (SW, _("When executing COMPUTE: %g is not a valid value as "
199 "an index into vector %s."),
200 index, compute->vector->name);
201 return TRNS_CONTINUE;
204 vr = compute->vector->var[rindx - 1];
205 expr_evaluate_str (compute->rvalue, c, case_num,
206 case_data_rw (c, vr->fv)->s, vr->width);
209 return TRNS_CONTINUE;
217 struct compute_trns *compute = NULL;
218 struct lvalue *lvalue = NULL;
220 compute = compute_trns_create ();
222 /* Test expression. */
223 compute->test = expr_parse (dataset_dict (current_dataset), EXPR_BOOLEAN);
224 if (compute->test == NULL)
227 /* Lvalue variable. */
228 lvalue = lvalue_parse ();
232 /* Rvalue expression. */
233 if (!lex_force_match ('='))
235 compute->rvalue = parse_rvalue (lvalue);
236 if (compute->rvalue == NULL)
239 add_transformation (current_dataset,
240 get_proc_func (lvalue), compute_trns_free, compute);
242 lvalue_finalize (lvalue, compute);
244 return lex_end_of_command ();
247 lvalue_destroy (lvalue);
248 compute_trns_free (compute);
249 return CMD_CASCADING_FAILURE;
252 /* Code common to COMPUTE and IF. */
254 static trns_proc_func *
255 get_proc_func (const struct lvalue *lvalue)
257 bool is_numeric = lvalue_get_type (lvalue) == NUMERIC;
258 bool is_vector = lvalue_is_vector (lvalue);
261 ? (is_vector ? compute_num_vec : compute_num)
262 : (is_vector ? compute_str_vec : compute_str));
265 /* Parses and returns an rvalue expression of the same type as
266 LVALUE, or a null pointer on failure. */
267 static struct expression *
268 parse_rvalue (const struct lvalue *lvalue)
270 bool is_numeric = lvalue_get_type (lvalue) == NUMERIC;
272 return expr_parse (dataset_dict (current_dataset), is_numeric ? EXPR_NUMBER : EXPR_STRING);
275 /* Returns a new struct compute_trns after initializing its fields. */
276 static struct compute_trns *
277 compute_trns_create (void)
279 struct compute_trns *compute = xmalloc (sizeof *compute);
280 compute->test = NULL;
281 compute->variable = NULL;
282 compute->vector = NULL;
283 compute->element = NULL;
284 compute->rvalue = NULL;
288 /* Deletes all the fields in COMPUTE. */
290 compute_trns_free (void *compute_)
292 struct compute_trns *compute = compute_;
296 expr_free (compute->test);
297 expr_free (compute->element);
298 expr_free (compute->rvalue);
304 /* COMPUTE or IF target variable or vector element. */
307 char var_name[LONG_NAME_LEN + 1]; /* Destination variable name, or "". */
308 const struct vector *vector; /* Destination vector, if any, or NULL. */
309 struct expression *element; /* Destination vector element, or NULL. */
312 /* Parses the target variable or vector element into a new
313 `struct lvalue', which is returned. */
314 static struct lvalue *
317 struct lvalue *lvalue;
319 lvalue = xmalloc (sizeof *lvalue);
320 lvalue->var_name[0] = '\0';
321 lvalue->vector = NULL;
322 lvalue->element = NULL;
324 if (!lex_force_id ())
327 if (lex_look_ahead () == '(')
330 lvalue->vector = dict_lookup_vector (dataset_dict (current_dataset), tokid);
331 if (lvalue->vector == NULL)
333 msg (SE, _("There is no vector named %s."), tokid);
337 /* Vector element. */
339 if (!lex_force_match ('('))
341 lvalue->element = expr_parse (dataset_dict (current_dataset), EXPR_NUMBER);
342 if (lvalue->element == NULL)
344 if (!lex_force_match (')'))
350 str_copy_trunc (lvalue->var_name, sizeof lvalue->var_name, tokid);
356 lvalue_destroy (lvalue);
360 /* Returns the type (NUMERIC or ALPHA) of the target variable or
363 lvalue_get_type (const struct lvalue *lvalue)
365 if (lvalue->vector == NULL)
367 struct variable *var = dict_lookup_var (dataset_dict (current_dataset), lvalue->var_name);
374 return lvalue->vector->var[0]->type;
377 /* Returns true if LVALUE has a vector as its target. */
379 lvalue_is_vector (const struct lvalue *lvalue)
381 return lvalue->vector != NULL;
384 /* Finalizes making LVALUE the target of COMPUTE, by creating the
385 target variable if necessary and setting fields in COMPUTE. */
387 lvalue_finalize (struct lvalue *lvalue, struct compute_trns *compute)
389 if (lvalue->vector == NULL)
391 compute->variable = dict_lookup_var (dataset_dict (current_dataset), lvalue->var_name);
392 if (compute->variable == NULL)
393 compute->variable = dict_create_var_assert (dataset_dict (current_dataset),
394 lvalue->var_name, 0);
396 compute->fv = compute->variable->fv;
397 compute->width = compute->variable->width;
399 /* Goofy behavior, but compatible: Turn off LEAVE. */
400 if (dict_class_from_id (compute->variable->name) != DC_SCRATCH)
401 compute->variable->leave = false;
405 compute->vector = lvalue->vector;
406 compute->element = lvalue->element;
407 lvalue->element = NULL;
410 lvalue_destroy (lvalue);
413 /* Destroys LVALUE. */
415 lvalue_destroy (struct lvalue *lvalue)
420 expr_free (lvalue->element);