+++ /dev/null
-/* PSPP - a program for statistical analysis.
- Copyright (C) 1997-9, 2000, 2009-2011 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 <limits.h>
-
-#include "data/case.h"
-#include "data/dataset.h"
-#include "data/dictionary.h"
-#include "data/settings.h"
-#include "data/transformations.h"
-#include "data/variable.h"
-#include "language/command.h"
-#include "language/data-io/inpt-pgm.h"
-#include "language/expressions/public.h"
-#include "language/lexer/lexer.h"
-#include "libpspp/assertion.h"
-#include "libpspp/compiler.h"
-#include "libpspp/message.h"
-#include "libpspp/misc.h"
-#include "libpspp/pool.h"
-#include "libpspp/str.h"
-
-#include "gl/xalloc.h"
-
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-
-struct loop_trns
- {
- /* a=a TO b [BY c]. */
- struct variable *index_var; /* Index variable. */
- struct expression *first_expr; /* Starting index. */
- struct expression *by_expr; /* Index increment (or NULL). */
- struct expression *last_expr; /* Terminal index. */
-
- /* IF condition for LOOP or END LOOP. */
- struct expression *loop_condition;
- struct expression *end_loop_condition;
-
- /* Inner transformations. */
- struct trns_chain xforms;
-
- /* State. */
- double cur, by, last; /* Index data. */
- int iteration; /* For MXLOOPS. */
- size_t resume_idx; /* For resuming after END CASE. */
- };
-
-static struct trns_class loop_trns_class;
-
-static int in_loop;
-
-static bool parse_if_clause (struct lexer *, struct dataset *,
- struct expression **);
-static bool parse_index_clause (struct dataset *, struct lexer *,
- struct loop_trns *);
-\f
-/* LOOP. */
-
-/* Parses LOOP. */
-int
-cmd_loop (struct lexer *lexer, struct dataset *ds)
-{
- struct loop_trns *loop = xmalloc (sizeof *loop);
- *loop = (struct loop_trns) { .resume_idx = SIZE_MAX };
-
- bool ok = true;
- while (lex_token (lexer) != T_ENDCMD && ok)
- {
- if (lex_match_id (lexer, "IF"))
- ok = parse_if_clause (lexer, ds, &loop->loop_condition);
- else
- ok = parse_index_clause (ds, lexer, loop);
- }
- if (ok)
- lex_end_of_command (lexer);
- lex_discard_rest_of_command (lexer);
-
- proc_push_transformations (ds);
- in_loop++;
- for (;;)
- {
- if (lex_token (lexer) == T_STOP)
- {
- lex_error_expecting (lexer, "END LOOP");
- ok = false;
- break;
- }
- else if (lex_match_phrase (lexer, "END LOOP"))
- {
- if (lex_match_id (lexer, "IF"))
- ok = parse_if_clause (lexer, ds, &loop->end_loop_condition) && ok;
- break;
- }
- else
- cmd_parse_in_state (lexer, ds,
- (in_input_program ()
- ? CMD_STATE_NESTED_INPUT_PROGRAM
- : CMD_STATE_NESTED_DATA));
- }
- in_loop--;
- proc_pop_transformations (ds, &loop->xforms);
-
- add_transformation (ds, &loop_trns_class, loop);
-
- return ok ? CMD_SUCCESS : CMD_FAILURE;
-}
-
-int
-cmd_inside_loop (struct lexer *lexer, struct dataset *ds UNUSED)
-{
- lex_ofs_error (lexer, 0, lex_ofs (lexer) - 1,
- _("This command cannot appear outside LOOP...END LOOP."));
- return CMD_FAILURE;
-}
-
-static enum trns_result
-break_trns_proc (void *aux UNUSED, struct ccase **c UNUSED,
- casenumber case_num UNUSED)
-{
- return TRNS_BREAK;
-}
-
-/* Parses BREAK. */
-int
-cmd_break (struct lexer *lexer, struct dataset *ds)
-{
- if (!in_loop)
- {
- cmd_inside_loop (lexer, ds);
- return CMD_FAILURE;
- }
-
- static const struct trns_class trns_class = {
- .name = "BREAK",
- .execute = break_trns_proc
- };
- add_transformation (ds, &trns_class, NULL);
-
- return CMD_SUCCESS;
-}
-
-/* Parses an IF clause for LOOP or END LOOP and stores the
- resulting expression to *CONDITION.
- Returns true if successful, false on failure. */
-static bool
-parse_if_clause (struct lexer *lexer, struct dataset *ds,
- struct expression **condition)
-{
- if (*condition != NULL)
- {
- lex_sbc_only_once (lexer, "IF");
- return false;
- }
-
- *condition = expr_parse_bool (lexer, ds);
- return *condition != NULL;
-}
-
-/* Parses an indexing clause into LOOP. Returns true if successful, false on
- failure. */
-static bool
-parse_index_clause (struct dataset *ds, struct lexer *lexer,
- struct loop_trns *loop)
-{
- if (loop->index_var != NULL)
- {
- lex_error (lexer, _("Only one index clause may be specified."));
- return false;
- }
-
- if (!lex_force_id (lexer))
- return false;
-
- loop->index_var = dict_lookup_var (dataset_dict (ds), lex_tokcstr (lexer));
- if (!loop->index_var)
- loop->index_var = dict_create_var_assert (dataset_dict (ds),
- lex_tokcstr (lexer), 0);
- lex_get (lexer);
-
- if (!lex_force_match (lexer, T_EQUALS))
- return false;
-
- loop->first_expr = expr_parse (lexer, ds, VAL_NUMERIC);
- if (loop->first_expr == NULL)
- return false;
-
- for (;;)
- {
- struct expression **e;
- if (lex_match (lexer, T_TO))
- e = &loop->last_expr;
- else if (lex_match (lexer, T_BY))
- e = &loop->by_expr;
- else
- break;
-
- if (*e != NULL)
- {
- lex_sbc_only_once (lexer, e == &loop->last_expr ? "TO" : "BY");
- return false;
- }
- *e = expr_parse (lexer, ds, VAL_NUMERIC);
- if (*e == NULL)
- return false;
- }
- if (loop->last_expr == NULL)
- {
- lex_sbc_missing (lexer, "TO");
- return false;
- }
-
- return true;
-}
-
-/* Sets up LOOP for the first pass. */
-static enum trns_result
-loop_trns_proc (void *loop_, struct ccase **c, casenumber case_num)
-{
- struct loop_trns *loop = loop_;
-
- size_t start_idx = loop->resume_idx;
- loop->resume_idx = SIZE_MAX;
- if (start_idx != SIZE_MAX)
- goto resume;
-
- if (loop->index_var)
- {
- /* Evaluate loop index expressions. */
- loop->cur = expr_evaluate_num (loop->first_expr, *c, case_num);
- loop->by = (loop->by_expr
- ? expr_evaluate_num (loop->by_expr, *c, case_num)
- : 1.0);
- loop->last = expr_evaluate_num (loop->last_expr, *c, case_num);
-
- /* Even if the loop is never entered, set the index
- variable to the initial value. */
- *c = case_unshare (*c);
- *case_num_rw (*c, loop->index_var) = loop->cur;
-
- /* Throw out pathological cases. */
- if (!isfinite (loop->cur)
- || !isfinite (loop->by)
- || !isfinite (loop->last)
- || loop->by == 0.0
- || (loop->by > 0.0 && loop->cur > loop->last)
- || (loop->by < 0.0 && loop->cur < loop->last))
- return TRNS_CONTINUE;
- }
-
- for (loop->iteration = 0;
- loop->index_var || loop->iteration < settings_get_mxloops ();
- loop->iteration++)
- {
- if (loop->loop_condition
- && expr_evaluate_num (loop->loop_condition, *c, case_num) != 1.0)
- break;
-
- start_idx = 0;
- resume:
- for (size_t i = start_idx; i < loop->xforms.n; i++)
- {
- const struct transformation *trns = &loop->xforms.xforms[i];
- enum trns_result r = trns->class->execute (trns->aux, c, case_num);
- switch (r)
- {
- case TRNS_CONTINUE:
- break;
-
- case TRNS_BREAK:
- return TRNS_CONTINUE;
-
- case TRNS_END_CASE:
- loop->resume_idx = i;
- return TRNS_END_CASE;
-
- case TRNS_ERROR:
- case TRNS_END_FILE:
- return r;
-
- case TRNS_DROP_CASE:
- NOT_REACHED ();
- }
- }
-
- if (loop->end_loop_condition != NULL
- && expr_evaluate_num (loop->end_loop_condition, *c, case_num) != 0.0)
- break;
-
- if (loop->index_var)
- {
- loop->cur += loop->by;
- if (loop->by > 0.0 ? loop->cur > loop->last : loop->cur < loop->last)
- break;
-
- *c = case_unshare (*c);
- *case_num_rw (*c, loop->index_var) = loop->cur;
- }
- }
- return TRNS_CONTINUE;
-}
-
-/* Frees LOOP. */
-static bool
-loop_trns_free (void *loop_)
-{
- struct loop_trns *loop = loop_;
-
- expr_free (loop->first_expr);
- expr_free (loop->by_expr);
- expr_free (loop->last_expr);
-
- expr_free (loop->loop_condition);
- expr_free (loop->end_loop_condition);
-
- trns_chain_uninit (&loop->xforms);
-
- free (loop);
- return true;
-}
-
-static struct trns_class loop_trns_class = {
- .name = "LOOP",
- .execute = loop_trns_proc,
- .destroy = loop_trns_free,
-};
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