-/* PSPP - a program for statistical analysis.
- Copyright (C) 1997-9, 2000, 2006, 2007, 2009, 2010 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 "data/procedure.h"
-
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-#include "data/case.h"
-#include "data/case-map.h"
-#include "data/caseinit.h"
-#include "data/casereader.h"
-#include "data/casereader-provider.h"
-#include "data/casereader-shim.h"
-#include "data/casewriter.h"
-#include "data/dictionary.h"
-#include "data/file-handle-def.h"
-#include "data/transformations.h"
-#include "data/variable.h"
-#include "libpspp/deque.h"
-#include "libpspp/misc.h"
-#include "libpspp/str.h"
-#include "libpspp/taint.h"
-#include "libpspp/i18n.h"
-
-#include "gl/minmax.h"
-#include "gl/xalloc.h"
-
-struct dataset {
- /* Cases are read from source,
- their transformation variables are initialized,
- pass through permanent_trns_chain (which transforms them into
- the format described by permanent_dict),
- are written to sink,
- pass through temporary_trns_chain (which transforms them into
- the format described by dict),
- and are finally passed to the procedure. */
- struct casereader *source;
- struct caseinit *caseinit;
- struct trns_chain *permanent_trns_chain;
- struct dictionary *permanent_dict;
- struct casewriter *sink;
- struct trns_chain *temporary_trns_chain;
- struct dictionary *dict;
-
- /* Callback which occurs whenever the transformation chain(s) have
- been modified */
- transformation_change_callback_func *xform_callback;
- void *xform_callback_aux;
-
- /* If true, cases are discarded instead of being written to
- sink. */
- bool discard_output;
-
- /* The transformation chain that the next transformation will be
- added to. */
- struct trns_chain *cur_trns_chain;
-
- /* The case map used to compact a case, if necessary;
- otherwise a null pointer. */
- struct case_map *compactor;
-
- /* Time at which proc was last invoked. */
- time_t last_proc_invocation;
-
- /* Cases just before ("lagging") the current one. */
- int n_lag; /* Number of cases to lag. */
- struct deque lag; /* Deque of lagged cases. */
- struct ccase **lag_cases; /* Lagged cases managed by deque. */
-
- /* Procedure data. */
- enum
- {
- PROC_COMMITTED, /* No procedure in progress. */
- PROC_OPEN, /* proc_open called, casereader still open. */
- PROC_CLOSED /* casereader from proc_open destroyed,
- but proc_commit not yet called. */
- }
- proc_state;
- casenumber cases_written; /* Cases output so far. */
- bool ok; /* Error status. */
- struct casereader_shim *shim; /* Shim on proc_open() casereader. */
-
- void (*callback) (void *); /* Callback for when the dataset changes */
- void *cb_data;
-
- /* Default encoding for reading syntax files. */
- char *syntax_encoding;
-}; /* struct dataset */
-
-
-static void add_case_limit_trns (struct dataset *ds);
-static void add_filter_trns (struct dataset *ds);
-
-static void update_last_proc_invocation (struct dataset *ds);
-
-static void
-dataset_set_unsaved (const struct dataset *ds)
-{
- if (ds->callback) ds->callback (ds->cb_data);
-}
-
-\f
-/* Public functions. */
-
-void
-dataset_set_callback (struct dataset *ds, void (*cb) (void *), void *cb_data)
-{
- ds->callback = cb;
- ds->cb_data = cb_data;
-}
-
-void
-dataset_set_default_syntax_encoding (struct dataset *ds, const char *encoding)
-{
- free (ds->syntax_encoding);
- ds->syntax_encoding = xstrdup (encoding);
-}
-
-const char *
-dataset_get_default_syntax_encoding (const struct dataset *ds)
-{
- return ds->syntax_encoding;
-}
-
-/* Returns the last time the data was read. */
-time_t
-time_of_last_procedure (struct dataset *ds)
-{
- if (ds->last_proc_invocation == 0)
- update_last_proc_invocation (ds);
- return ds->last_proc_invocation;
-}
-\f
-/* Regular procedure. */
-
-/* Executes any pending transformations, if necessary.
- This is not identical to the EXECUTE command in that it won't
- always read the source data. This can be important when the
- source data is given inline within BEGIN DATA...END FILE. */
-bool
-proc_execute (struct dataset *ds)
-{
- bool ok;
-
- if ((ds->temporary_trns_chain == NULL
- || trns_chain_is_empty (ds->temporary_trns_chain))
- && trns_chain_is_empty (ds->permanent_trns_chain))
- {
- ds->n_lag = 0;
- ds->discard_output = false;
- dict_set_case_limit (ds->dict, 0);
- dict_clear_vectors (ds->dict);
- return true;
- }
-
- ok = casereader_destroy (proc_open (ds));
- return proc_commit (ds) && ok;
-}
-
-static const struct casereader_class proc_casereader_class;
-
-/* Opens dataset DS for reading cases with proc_read. If FILTER is true, then
- cases filtered out with FILTER BY will not be included in the casereader
- (which is usually desirable). If FILTER is false, all cases will be
- included regardless of FILTER BY settings.
-
- proc_commit must be called when done. */
-struct casereader *
-proc_open_filtering (struct dataset *ds, bool filter)
-{
- struct casereader *reader;
-
- assert (ds->source != NULL);
- assert (ds->proc_state == PROC_COMMITTED);
-
- update_last_proc_invocation (ds);
-
- caseinit_mark_for_init (ds->caseinit, ds->dict);
-
- /* Finish up the collection of transformations. */
- add_case_limit_trns (ds);
- if (filter)
- add_filter_trns (ds);
- trns_chain_finalize (ds->cur_trns_chain);
-
- /* Make permanent_dict refer to the dictionary right before
- data reaches the sink. */
- if (ds->permanent_dict == NULL)
- ds->permanent_dict = ds->dict;
-
- /* Prepare sink. */
- if (!ds->discard_output)
- {
- struct dictionary *pd = ds->permanent_dict;
- size_t compacted_value_cnt = dict_count_values (pd, 1u << DC_SCRATCH);
- if (compacted_value_cnt < dict_get_next_value_idx (pd))
- {
- struct caseproto *compacted_proto;
- compacted_proto = dict_get_compacted_proto (pd, 1u << DC_SCRATCH);
- ds->compactor = case_map_to_compact_dict (pd, 1u << DC_SCRATCH);
- ds->sink = autopaging_writer_create (compacted_proto);
- caseproto_unref (compacted_proto);
- }
- else
- {
- ds->compactor = NULL;
- ds->sink = autopaging_writer_create (dict_get_proto (pd));
- }
- }
- else
- {
- ds->compactor = NULL;
- ds->sink = NULL;
- }
-
- /* Allocate memory for lagged cases. */
- ds->lag_cases = deque_init (&ds->lag, ds->n_lag, sizeof *ds->lag_cases);
-
- ds->proc_state = PROC_OPEN;
- ds->cases_written = 0;
- ds->ok = true;
-
- /* FIXME: use taint in dataset in place of `ok'? */
- /* FIXME: for trivial cases we can just return a clone of
- ds->source? */
-
- /* Create casereader and insert a shim on top. The shim allows us to
- arbitrarily extend the casereader's lifetime, by slurping the cases into
- the shim's buffer in proc_commit(). That is especially useful when output
- table_items are generated directly from the procedure casereader (e.g. by
- the LIST procedure) when we are using an output driver that keeps a
- reference to the output items passed to it (e.g. the GUI output driver in
- PSPPIRE). */
- reader = casereader_create_sequential (NULL, dict_get_proto (ds->dict),
- CASENUMBER_MAX,
- &proc_casereader_class, ds);
- ds->shim = casereader_shim_insert (reader);
- return reader;
-}
-
-/* Opens dataset DS for reading cases with proc_read.
- proc_commit must be called when done. */
-struct casereader *
-proc_open (struct dataset *ds)
-{
- return proc_open_filtering (ds, true);
-}
-
-/* Returns true if a procedure is in progress, that is, if
- proc_open has been called but proc_commit has not. */
-bool
-proc_is_open (const struct dataset *ds)
-{
- return ds->proc_state != PROC_COMMITTED;
-}
-
-/* "read" function for procedure casereader. */
-static struct ccase *
-proc_casereader_read (struct casereader *reader UNUSED, void *ds_)
-{
- struct dataset *ds = ds_;
- enum trns_result retval = TRNS_DROP_CASE;
- struct ccase *c;
-
- assert (ds->proc_state == PROC_OPEN);
- for (; ; case_unref (c))
- {
- casenumber case_nr;
-
- assert (retval == TRNS_DROP_CASE || retval == TRNS_ERROR);
- if (retval == TRNS_ERROR)
- ds->ok = false;
- if (!ds->ok)
- return NULL;
-
- /* Read a case from source. */
- c = casereader_read (ds->source);
- if (c == NULL)
- return NULL;
- c = case_unshare_and_resize (c, dict_get_proto (ds->dict));
- caseinit_init_vars (ds->caseinit, c);
-
- /* Execute permanent transformations. */
- case_nr = ds->cases_written + 1;
- retval = trns_chain_execute (ds->permanent_trns_chain, TRNS_CONTINUE,
- &c, case_nr);
- caseinit_update_left_vars (ds->caseinit, c);
- if (retval != TRNS_CONTINUE)
- continue;
-
- /* Write case to collection of lagged cases. */
- if (ds->n_lag > 0)
- {
- while (deque_count (&ds->lag) >= ds->n_lag)
- case_unref (ds->lag_cases[deque_pop_back (&ds->lag)]);
- ds->lag_cases[deque_push_front (&ds->lag)] = case_ref (c);
- }
-
- /* Write case to replacement active file. */
- ds->cases_written++;
- if (ds->sink != NULL)
- casewriter_write (ds->sink,
- case_map_execute (ds->compactor, case_ref (c)));
-
- /* Execute temporary transformations. */
- if (ds->temporary_trns_chain != NULL)
- {
- retval = trns_chain_execute (ds->temporary_trns_chain, TRNS_CONTINUE,
- &c, ds->cases_written);
- if (retval != TRNS_CONTINUE)
- continue;
- }
-
- return c;
- }
-}
-
-/* "destroy" function for procedure casereader. */
-static void
-proc_casereader_destroy (struct casereader *reader, void *ds_)
-{
- struct dataset *ds = ds_;
- struct ccase *c;
-
- /* We are always the subreader for a casereader_buffer, so if we're being
- destroyed then it's because the casereader_buffer has read all the cases
- that it ever will. */
- ds->shim = NULL;
-
- /* Make sure transformations happen for every input case, in
- case they have side effects, and ensure that the replacement
- active file gets all the cases it should. */
- while ((c = casereader_read (reader)) != NULL)
- case_unref (c);
-
- ds->proc_state = PROC_CLOSED;
- ds->ok = casereader_destroy (ds->source) && ds->ok;
- ds->source = NULL;
- proc_set_active_file_data (ds, NULL);
-}
-
-/* Must return false if the source casereader, a transformation,
- or the sink casewriter signaled an error. (If a temporary
- transformation signals an error, then the return value is
- false, but the replacement active file may still be
- untainted.) */
-bool
-proc_commit (struct dataset *ds)
-{
- if (ds->shim != NULL)
- casereader_shim_slurp (ds->shim);
-
- assert (ds->proc_state == PROC_CLOSED);
- ds->proc_state = PROC_COMMITTED;
-
- dataset_set_unsaved (ds);
-
- /* Free memory for lagged cases. */
- while (!deque_is_empty (&ds->lag))
- case_unref (ds->lag_cases[deque_pop_back (&ds->lag)]);
- free (ds->lag_cases);
-
- /* Dictionary from before TEMPORARY becomes permanent. */
- proc_cancel_temporary_transformations (ds);
-
- if (!ds->discard_output)
- {
- /* Finish compacting. */
- if (ds->compactor != NULL)
- {
- case_map_destroy (ds->compactor);
- ds->compactor = NULL;
-
- dict_delete_scratch_vars (ds->dict);
- dict_compact_values (ds->dict);
- }
-
- /* Old data sink becomes new data source. */
- if (ds->sink != NULL)
- ds->source = casewriter_make_reader (ds->sink);
- }
- else
- {
- ds->source = NULL;
- ds->discard_output = false;
- }
- ds->sink = NULL;
-
- caseinit_clear (ds->caseinit);
- caseinit_mark_as_preinited (ds->caseinit, ds->dict);
-
- dict_clear_vectors (ds->dict);
- ds->permanent_dict = NULL;
- return proc_cancel_all_transformations (ds) && ds->ok;
-}
-
-/* Casereader class for procedure execution. */
-static const struct casereader_class proc_casereader_class =
- {
- proc_casereader_read,
- proc_casereader_destroy,
- NULL,
- NULL,
- };
-
-/* Updates last_proc_invocation. */
-static void
-update_last_proc_invocation (struct dataset *ds)
-{
- ds->last_proc_invocation = time (NULL);
-}
-\f
-/* Returns a pointer to the lagged case from N_BEFORE cases before the
- current one, or NULL if there haven't been that many cases yet. */
-const struct ccase *
-lagged_case (const struct dataset *ds, int n_before)
-{
- assert (n_before >= 1);
- assert (n_before <= ds->n_lag);
-
- if (n_before <= deque_count (&ds->lag))
- return ds->lag_cases[deque_front (&ds->lag, n_before - 1)];
- else
- return NULL;
-}
-\f
-/* Returns the current set of permanent transformations,
- and clears the permanent transformations.
- For use by INPUT PROGRAM. */
-struct trns_chain *
-proc_capture_transformations (struct dataset *ds)
-{
- struct trns_chain *chain;
-
- assert (ds->temporary_trns_chain == NULL);
- chain = ds->permanent_trns_chain;
- ds->cur_trns_chain = ds->permanent_trns_chain = trns_chain_create ();
-
- if ( ds->xform_callback)
- ds->xform_callback (false, ds->xform_callback_aux);
-
- return chain;
-}
-
-/* Adds a transformation that processes a case with PROC and
- frees itself with FREE to the current set of transformations.
- The functions are passed AUX as auxiliary data. */
-void
-add_transformation (struct dataset *ds, trns_proc_func *proc, trns_free_func *free, void *aux)
-{
- trns_chain_append (ds->cur_trns_chain, NULL, proc, free, aux);
- if ( ds->xform_callback)
- ds->xform_callback (true, ds->xform_callback_aux);
-}
-
-/* Adds a transformation that processes a case with PROC and
- frees itself with FREE to the current set of transformations.
- When parsing of the block of transformations is complete,
- FINALIZE will be called.
- The functions are passed AUX as auxiliary data. */
-void
-add_transformation_with_finalizer (struct dataset *ds,
- trns_finalize_func *finalize,
- trns_proc_func *proc,
- trns_free_func *free, void *aux)
-{
- trns_chain_append (ds->cur_trns_chain, finalize, proc, free, aux);
-
- if ( ds->xform_callback)
- ds->xform_callback (true, ds->xform_callback_aux);
-}
-
-/* Returns the index of the next transformation.
- This value can be returned by a transformation procedure
- function to indicate a "jump" to that transformation. */
-size_t
-next_transformation (const struct dataset *ds)
-{
- return trns_chain_next (ds->cur_trns_chain);
-}
-
-/* Returns true if the next call to add_transformation() will add
- a temporary transformation, false if it will add a permanent
- transformation. */
-bool
-proc_in_temporary_transformations (const struct dataset *ds)
-{
- return ds->temporary_trns_chain != NULL;
-}
-
-/* Marks the start of temporary transformations.
- Further calls to add_transformation() will add temporary
- transformations. */
-void
-proc_start_temporary_transformations (struct dataset *ds)
-{
- if (!proc_in_temporary_transformations (ds))
- {
- add_case_limit_trns (ds);
-
- ds->permanent_dict = dict_clone (ds->dict);
-
- trns_chain_finalize (ds->permanent_trns_chain);
- ds->temporary_trns_chain = ds->cur_trns_chain = trns_chain_create ();
-
- if ( ds->xform_callback)
- ds->xform_callback (true, ds->xform_callback_aux);
- }
-}
-
-/* Converts all the temporary transformations, if any, to
- permanent transformations. Further transformations will be
- permanent.
- Returns true if anything changed, false otherwise. */
-bool
-proc_make_temporary_transformations_permanent (struct dataset *ds)
-{
- if (proc_in_temporary_transformations (ds))
- {
- trns_chain_finalize (ds->temporary_trns_chain);
- trns_chain_splice (ds->permanent_trns_chain, ds->temporary_trns_chain);
- ds->temporary_trns_chain = NULL;
-
- dict_destroy (ds->permanent_dict);
- ds->permanent_dict = NULL;
-
- return true;
- }
- else
- return false;
-}
-
-/* Cancels all temporary transformations, if any. Further
- transformations will be permanent.
- Returns true if anything changed, false otherwise. */
-bool
-proc_cancel_temporary_transformations (struct dataset *ds)
-{
- if (proc_in_temporary_transformations (ds))
- {
- dict_destroy (ds->dict);
- ds->dict = ds->permanent_dict;
- ds->permanent_dict = NULL;
-
- trns_chain_destroy (ds->temporary_trns_chain);
- ds->temporary_trns_chain = NULL;
-
- if ( ds->xform_callback)
- ds->xform_callback (!trns_chain_is_empty (ds->permanent_trns_chain),
- ds->xform_callback_aux);
-
- return true;
- }
- else
- return false;
-}
-
-/* Cancels all transformations, if any.
- Returns true if successful, false on I/O error. */
-bool
-proc_cancel_all_transformations (struct dataset *ds)
-{
- bool ok;
- assert (ds->proc_state == PROC_COMMITTED);
- ok = trns_chain_destroy (ds->permanent_trns_chain);
- ok = trns_chain_destroy (ds->temporary_trns_chain) && ok;
- ds->permanent_trns_chain = ds->cur_trns_chain = trns_chain_create ();
- ds->temporary_trns_chain = NULL;
- if ( ds->xform_callback)
- ds->xform_callback (false, ds->xform_callback_aux);
-
- return ok;
-}
-\f
-
-static void
-dict_callback (struct dictionary *d UNUSED, void *ds_)
-{
- struct dataset *ds = ds_;
- dataset_set_unsaved (ds);
-}
-
-/* Initializes procedure handling. */
-struct dataset *
-create_dataset (void)
-{
- struct dataset *ds = xzalloc (sizeof(*ds));
- ds->dict = dict_create ();
-
- dict_set_change_callback (ds->dict, dict_callback, ds);
-
- dict_set_encoding (ds->dict, get_default_encoding ());
-
- ds->caseinit = caseinit_create ();
- proc_cancel_all_transformations (ds);
-
- ds->syntax_encoding = xstrdup ("Auto");
-
- return ds;
-}
-
-
-void
-dataset_add_transform_change_callback (struct dataset *ds,
- transformation_change_callback_func *cb,
- void *aux)
-{
- ds->xform_callback = cb;
- ds->xform_callback_aux = aux;
-}
-
-/* Finishes up procedure handling. */
-void
-destroy_dataset (struct dataset *ds)
-{
- proc_discard_active_file (ds);
- dict_destroy (ds->dict);
- caseinit_destroy (ds->caseinit);
- trns_chain_destroy (ds->permanent_trns_chain);
-
- if ( ds->xform_callback)
- ds->xform_callback (false, ds->xform_callback_aux);
-
- free (ds->syntax_encoding);
- free (ds);
-}
-
-/* Causes output from the next procedure to be discarded, instead
- of being preserved for use as input for the next procedure. */
-void
-proc_discard_output (struct dataset *ds)
-{
- ds->discard_output = true;
-}
-
-/* Discards the active file dictionary, data, and
- transformations. */
-void
-proc_discard_active_file (struct dataset *ds)
-{
- assert (ds->proc_state == PROC_COMMITTED);
-
- dict_clear (ds->dict);
- fh_set_default_handle (NULL);
-
- ds->n_lag = 0;
-
- casereader_destroy (ds->source);
- ds->source = NULL;
-
- proc_cancel_all_transformations (ds);
-}
-
-/* Sets SOURCE as the source for procedure input for the next
- procedure. */
-void
-proc_set_active_file (struct dataset *ds,
- struct casereader *source,
- struct dictionary *dict)
-{
- assert (ds->proc_state == PROC_COMMITTED);
- assert (ds->dict != dict);
-
- proc_discard_active_file (ds);
-
- dict_destroy (ds->dict);
- ds->dict = dict;
- dict_set_change_callback (ds->dict, dict_callback, ds);
-
- proc_set_active_file_data (ds, source);
-}
-
-/* Replaces the active file's data by READER without replacing
- the associated dictionary. */
-bool
-proc_set_active_file_data (struct dataset *ds, struct casereader *reader)
-{
- casereader_destroy (ds->source);
- ds->source = reader;
-
- caseinit_clear (ds->caseinit);
- caseinit_mark_as_preinited (ds->caseinit, ds->dict);
-
- return reader == NULL || !casereader_error (reader);
-}
-
-/* Returns true if an active file data source is available, false
- otherwise. */
-bool
-proc_has_active_file (const struct dataset *ds)
-{
- return ds->source != NULL;
-}
-
-/* Returns the active file data source from DS, or a null pointer
- if DS has no data source, and removes it from DS. */
-struct casereader *
-proc_extract_active_file_data (struct dataset *ds)
-{
- struct casereader *reader = ds->source;
- ds->source = NULL;
-
- return reader;
-}
-
-/* Checks whether DS has a corrupted active file. If so,
- discards it and returns false. If not, returns true without
- doing anything. */
-bool
-dataset_end_of_command (struct dataset *ds)
-{
- if (ds->source != NULL)
- {
- if (casereader_error (ds->source))
- {
- proc_discard_active_file (ds);
- return false;
- }
- else
- {
- const struct taint *taint = casereader_get_taint (ds->source);
- taint_reset_successor_taint (CONST_CAST (struct taint *, taint));
- assert (!taint_has_tainted_successor (taint));
- }
- }
- return true;
-}
-\f
-static trns_proc_func case_limit_trns_proc;
-static trns_free_func case_limit_trns_free;
-
-/* Adds a transformation that limits the number of cases that may
- pass through, if DS->DICT has a case limit. */
-static void
-add_case_limit_trns (struct dataset *ds)
-{
- casenumber case_limit = dict_get_case_limit (ds->dict);
- if (case_limit != 0)
- {
- casenumber *cases_remaining = xmalloc (sizeof *cases_remaining);
- *cases_remaining = case_limit;
- add_transformation (ds, case_limit_trns_proc, case_limit_trns_free,
- cases_remaining);
- dict_set_case_limit (ds->dict, 0);
- }
-}
-
-/* Limits the maximum number of cases processed to
- *CASES_REMAINING. */
-static int
-case_limit_trns_proc (void *cases_remaining_,
- struct ccase **c UNUSED, casenumber case_nr UNUSED)
-{
- size_t *cases_remaining = cases_remaining_;
- if (*cases_remaining > 0)
- {
- (*cases_remaining)--;
- return TRNS_CONTINUE;
- }
- else
- return TRNS_DROP_CASE;
-}
-
-/* Frees the data associated with a case limit transformation. */
-static bool
-case_limit_trns_free (void *cases_remaining_)
-{
- size_t *cases_remaining = cases_remaining_;
- free (cases_remaining);
- return true;
-}
-\f
-static trns_proc_func filter_trns_proc;
-
-/* Adds a temporary transformation to filter data according to
- the variable specified on FILTER, if any. */
-static void
-add_filter_trns (struct dataset *ds)
-{
- struct variable *filter_var = dict_get_filter (ds->dict);
- if (filter_var != NULL)
- {
- proc_start_temporary_transformations (ds);
- add_transformation (ds, filter_trns_proc, NULL, filter_var);
- }
-}
-
-/* FILTER transformation. */
-static int
-filter_trns_proc (void *filter_var_,
- struct ccase **c UNUSED, casenumber case_nr UNUSED)
-
-{
- struct variable *filter_var = filter_var_;
- double f = case_num (*c, filter_var);
- return (f != 0.0 && !var_is_num_missing (filter_var, f, MV_ANY)
- ? TRNS_CONTINUE : TRNS_DROP_CASE);
-}
-
-
-struct dictionary *
-dataset_dict (const struct dataset *ds)
-{
- return ds->dict;
-}
-
-const struct casereader *
-dataset_source (const struct dataset *ds)
-{
- return ds->source;
-}
-
-void
-dataset_need_lag (struct dataset *ds, int n_before)
-{
- ds->n_lag = MAX (ds->n_lag, n_before);
-}