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 (struct lexer *lexer, struct dataset *);
47 static int lvalue_get_type (const struct lvalue *, const struct dictionary *);
48 static bool lvalue_is_vector (const struct lvalue *);
49 static void lvalue_finalize (struct lvalue *,
50 struct compute_trns *, struct dictionary *);
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 (struct lexer *lexer,
73 const struct lvalue *,
76 static struct compute_trns *compute_trns_create (void);
77 static trns_proc_func *get_proc_func (const struct lvalue *, const struct dictionary *);
78 static trns_free_func compute_trns_free;
83 cmd_compute (struct lexer *lexer, struct dataset *ds)
85 struct dictionary *dict = dataset_dict (ds);
86 struct lvalue *lvalue = NULL;
87 struct compute_trns *compute = NULL;
89 compute = compute_trns_create ();
91 lvalue = lvalue_parse (lexer, ds);
95 if (!lex_force_match (lexer, '='))
97 compute->rvalue = parse_rvalue (lexer, lvalue, ds);
98 if (compute->rvalue == NULL)
101 add_transformation (ds, get_proc_func (lvalue, dict),
102 compute_trns_free, compute);
104 lvalue_finalize (lvalue, compute, dict);
106 return lex_end_of_command (lexer);
109 lvalue_destroy (lvalue);
110 compute_trns_free (compute);
111 return CMD_CASCADING_FAILURE;
114 /* Transformation functions. */
116 /* Handle COMPUTE or IF with numeric target variable. */
118 compute_num (void *compute_, struct ccase *c, casenumber case_num)
120 struct compute_trns *compute = compute_;
122 if (compute->test == NULL
123 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
124 case_data_rw (c, compute->fv)->f = expr_evaluate_num (compute->rvalue, c,
127 return TRNS_CONTINUE;
130 /* Handle COMPUTE or IF with numeric vector element target
133 compute_num_vec (void *compute_, struct ccase *c, casenumber case_num)
135 struct compute_trns *compute = compute_;
137 if (compute->test == NULL
138 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
140 double index; /* Index into the vector. */
141 int rindx; /* Rounded index value. */
143 index = expr_evaluate_num (compute->element, c, case_num);
144 rindx = floor (index + EPSILON);
145 if (index == SYSMIS || rindx < 1 || rindx > compute->vector->cnt)
148 msg (SW, _("When executing COMPUTE: SYSMIS is not a valid value as "
149 "an index into vector %s."), compute->vector->name);
151 msg (SW, _("When executing COMPUTE: %g is not a valid value as "
152 "an index into vector %s."),
153 index, compute->vector->name);
154 return TRNS_CONTINUE;
156 case_data_rw (c, compute->vector->var[rindx - 1]->fv)->f
157 = expr_evaluate_num (compute->rvalue, c, case_num);
160 return TRNS_CONTINUE;
163 /* Handle COMPUTE or IF with string target variable. */
165 compute_str (void *compute_, struct ccase *c, casenumber case_num)
167 struct compute_trns *compute = compute_;
169 if (compute->test == NULL
170 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
171 expr_evaluate_str (compute->rvalue, c, case_num,
172 case_data_rw (c, compute->fv)->s, compute->width);
174 return TRNS_CONTINUE;
177 /* Handle COMPUTE or IF with string vector element target
180 compute_str_vec (void *compute_, struct ccase *c, casenumber case_num)
182 struct compute_trns *compute = compute_;
184 if (compute->test == NULL
185 || expr_evaluate_num (compute->test, c, case_num) == 1.0)
187 double index; /* Index into the vector. */
188 int rindx; /* Rounded index value. */
189 struct variable *vr; /* Variable reference by indexed vector. */
191 index = expr_evaluate_num (compute->element, c, case_num);
192 rindx = floor (index + EPSILON);
195 msg (SW, _("When executing COMPUTE: SYSMIS is not a valid "
196 "value as an index into vector %s."),
197 compute->vector->name);
198 return TRNS_CONTINUE;
200 else if (rindx < 1 || rindx > compute->vector->cnt)
202 msg (SW, _("When executing COMPUTE: %g is not a valid value as "
203 "an index into vector %s."),
204 index, compute->vector->name);
205 return TRNS_CONTINUE;
208 vr = compute->vector->var[rindx - 1];
209 expr_evaluate_str (compute->rvalue, c, case_num,
210 case_data_rw (c, vr->fv)->s, vr->width);
213 return TRNS_CONTINUE;
219 cmd_if (struct lexer *lexer, struct dataset *ds)
221 struct dictionary *dict = dataset_dict (ds);
222 struct compute_trns *compute = NULL;
223 struct lvalue *lvalue = NULL;
225 compute = compute_trns_create ();
227 /* Test expression. */
228 compute->test = expr_parse (lexer, ds, EXPR_BOOLEAN);
229 if (compute->test == NULL)
232 /* Lvalue variable. */
233 lvalue = lvalue_parse (lexer, ds);
237 /* Rvalue expression. */
238 if (!lex_force_match (lexer, '='))
240 compute->rvalue = parse_rvalue (lexer, lvalue, ds);
241 if (compute->rvalue == NULL)
244 add_transformation (ds, get_proc_func (lvalue, dict),
245 compute_trns_free, compute);
247 lvalue_finalize (lvalue, compute, dict);
249 return lex_end_of_command (lexer);
252 lvalue_destroy (lvalue);
253 compute_trns_free (compute);
254 return CMD_CASCADING_FAILURE;
257 /* Code common to COMPUTE and IF. */
259 static trns_proc_func *
260 get_proc_func (const struct lvalue *lvalue, const struct dictionary *dict)
262 bool is_numeric = lvalue_get_type (lvalue, dict) == NUMERIC;
263 bool is_vector = lvalue_is_vector (lvalue);
266 ? (is_vector ? compute_num_vec : compute_num)
267 : (is_vector ? compute_str_vec : compute_str));
270 /* Parses and returns an rvalue expression of the same type as
271 LVALUE, or a null pointer on failure. */
272 static struct expression *
273 parse_rvalue (struct lexer *lexer,
274 const struct lvalue *lvalue, struct dataset *ds)
276 const struct dictionary *dict = dataset_dict (ds);
277 bool is_numeric = lvalue_get_type (lvalue, dict) == NUMERIC;
279 return expr_parse (lexer, ds, is_numeric ? EXPR_NUMBER : EXPR_STRING);
282 /* Returns a new struct compute_trns after initializing its fields. */
283 static struct compute_trns *
284 compute_trns_create (void)
286 struct compute_trns *compute = xmalloc (sizeof *compute);
287 compute->test = NULL;
288 compute->variable = NULL;
289 compute->vector = NULL;
290 compute->element = NULL;
291 compute->rvalue = NULL;
295 /* Deletes all the fields in COMPUTE. */
297 compute_trns_free (void *compute_)
299 struct compute_trns *compute = compute_;
303 expr_free (compute->test);
304 expr_free (compute->element);
305 expr_free (compute->rvalue);
311 /* COMPUTE or IF target variable or vector element. */
314 char var_name[LONG_NAME_LEN + 1]; /* Destination variable name, or "". */
315 const struct vector *vector; /* Destination vector, if any, or NULL. */
316 struct expression *element; /* Destination vector element, or NULL. */
319 /* Parses the target variable or vector element into a new
320 `struct lvalue', which is returned. */
321 static struct lvalue *
322 lvalue_parse (struct lexer *lexer, struct dataset *ds)
324 struct lvalue *lvalue;
326 lvalue = xmalloc (sizeof *lvalue);
327 lvalue->var_name[0] = '\0';
328 lvalue->vector = NULL;
329 lvalue->element = NULL;
331 if (!lex_force_id (lexer))
334 if (lex_look_ahead (lexer) == '(')
337 lvalue->vector = dict_lookup_vector (dataset_dict (ds), lex_tokid (lexer));
338 if (lvalue->vector == NULL)
340 msg (SE, _("There is no vector named %s."), lex_tokid (lexer));
344 /* Vector element. */
346 if (!lex_force_match (lexer, '('))
348 lvalue->element = expr_parse (lexer, ds, EXPR_NUMBER);
349 if (lvalue->element == NULL)
351 if (!lex_force_match (lexer, ')'))
357 str_copy_trunc (lvalue->var_name, sizeof lvalue->var_name, lex_tokid (lexer));
363 lvalue_destroy (lvalue);
367 /* Returns the type (NUMERIC or ALPHA) of the target variable or
370 lvalue_get_type (const struct lvalue *lvalue, const struct dictionary *dict)
372 if (lvalue->vector == NULL)
374 struct variable *var = dict_lookup_var (dict, lvalue->var_name);
381 return lvalue->vector->var[0]->type;
384 /* Returns true if LVALUE has a vector as its target. */
386 lvalue_is_vector (const struct lvalue *lvalue)
388 return lvalue->vector != NULL;
391 /* Finalizes making LVALUE the target of COMPUTE, by creating the
392 target variable if necessary and setting fields in COMPUTE. */
394 lvalue_finalize (struct lvalue *lvalue,
395 struct compute_trns *compute,
396 struct dictionary *dict)
398 if (lvalue->vector == NULL)
400 compute->variable = dict_lookup_var (dict, lvalue->var_name);
401 if (compute->variable == NULL)
402 compute->variable = dict_create_var_assert (dict, lvalue->var_name, 0);
404 compute->fv = compute->variable->fv;
405 compute->width = compute->variable->width;
407 /* Goofy behavior, but compatible: Turn off LEAVE. */
408 if (dict_class_from_id (compute->variable->name) != DC_SCRATCH)
409 compute->variable->leave = false;
413 compute->vector = lvalue->vector;
414 compute->element = lvalue->element;
415 lvalue->element = NULL;
418 lvalue_destroy (lvalue);
421 /* Destroys LVALUE. */
423 lvalue_destroy (struct lvalue *lvalue)
428 expr_free (lvalue->element);