+/*
+ * Copyright (c) 1995, the EUROPAGATE consortium (see below).
+ *
+ * The EUROPAGATE consortium members are:
+ *
+ * University College Dublin
+ * Danmarks Teknologiske Videnscenter
+ * An Chomhairle Leabharlanna
+ * Consejo Superior de Investigaciones Cientificas
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation, in whole or in part, for any purpose, is hereby granted,
+ * provided that:
+ *
+ * 1. This copyright and permission notice appear in all copies of the
+ * software and its documentation. Notices of copyright or attribution
+ * which appear at the beginning of any file must remain unchanged.
+ *
+ * 2. The names of EUROPAGATE or the project partners may not be used to
+ * endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * 3. Users of this software (implementors and gateway operators) agree to
+ * inform the EUROPAGATE consortium of their use of the software. This
+ * information will be used to evaluate the EUROPAGATE project and the
+ * software, and to plan further developments. The consortium may use
+ * the information in later publications.
+ *
+ * 4. Users of this software agree to make their best efforts, when
+ * documenting their use of the software, to acknowledge the EUROPAGATE
+ * consortium, and the role played by the software in their work.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS, IMPLIED, OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ * IN NO EVENT SHALL THE EUROPAGATE CONSORTIUM OR ITS MEMBERS BE LIABLE
+ * FOR ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF
+ * ANY KIND, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
+ * OR PROFITS, WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND
+ * ON ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
+ * USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+/**
+ * \file ccl_stop_words.c
+ * \brief Removes stop words from terms in RPN tree
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <yaz/ccl.h>
+#include <yaz/nmem.h>
+
+struct ccl_stop_info {
+ char *qualname;
+ char *term;
+ struct ccl_stop_info *next;
+};
+
+struct ccl_stop_words {
+ char *blank_chars;
+ NMEM nmem; /* memory for removed items */
+ struct ccl_stop_info *removed_items;
+};
+
+static void append_removed_item(ccl_stop_words_t csw,
+ const char *qname,
+ const char *t, size_t len)
+{
+ struct ccl_stop_info *csi = nmem_malloc(csw->nmem, sizeof(*csi));
+ struct ccl_stop_info **csip = &csw->removed_items;
+ if (qname)
+ csi->qualname = nmem_strdup(csw->nmem, qname);
+ else
+ csi->qualname = 0;
+
+ csi->term = nmem_malloc(csw->nmem, len+1);
+ memcpy(csi->term, t, len);
+ csi->term[len] = '\0';
+ csi->next = 0;
+
+ while (*csip)
+ csip = &(*csip)->next;
+
+ *csip = csi;
+}
+
+ccl_stop_words_t ccl_stop_words_create(void)
+{
+ NMEM nmem = nmem_create();
+ ccl_stop_words_t csw = xmalloc(sizeof(*csw));
+ csw->nmem = nmem;
+ csw->removed_items = 0;
+ csw->blank_chars = xstrdup(" \r\n\t");
+ return csw;
+}
+
+void ccl_stop_words_destroy(ccl_stop_words_t csw)
+{
+ if (csw)
+ {
+ nmem_destroy(csw->nmem);
+ xfree(csw->blank_chars);
+ xfree(csw);
+ }
+}
+
+struct ccl_rpn_node *ccl_remove_stop_r(ccl_stop_words_t csw,
+ CCL_bibset bibset,
+ struct ccl_rpn_node *p)
+{
+ struct ccl_rpn_node *left, *right;
+ switch (p->kind)
+ {
+ case CCL_RPN_AND:
+ case CCL_RPN_OR:
+ case CCL_RPN_NOT:
+ case CCL_RPN_PROX:
+ left = ccl_remove_stop_r(csw, bibset, p->u.p[0]);
+ right = ccl_remove_stop_r(csw, bibset, p->u.p[1]);
+ if (!left || !right)
+ {
+ /* we must delete our binary node and return child (if any) */
+ p->u.p[0] = 0;
+ p->u.p[1] = 0;
+ ccl_rpn_delete(p);
+ if (left)
+ return left;
+ else
+ return right;
+ }
+ break;
+ case CCL_RPN_SET:
+ break;
+ case CCL_RPN_TERM:
+ if (p->u.t.term)
+ {
+ int found = 1;
+ while (found)
+ {
+ char *cp = p->u.t.term;
+ found = 0;
+ while (1)
+ {
+ while (*cp && strchr(csw->blank_chars, *cp))
+ cp++;
+ if (!*cp)
+ break;
+ else
+ {
+ char *cp0 = cp;
+ while (*cp && !strchr(csw->blank_chars, *cp))
+ cp++;
+ if (cp != cp0)
+ {
+ size_t len = cp - cp0;
+ if (ccl_search_stop(bibset, p->u.t.qual,
+ cp0, len))
+ {
+ append_removed_item(csw, p->u.t.qual,
+ cp0, len);
+ while (*cp && strchr(csw->blank_chars, *cp))
+ cp++;
+ memmove(cp0, cp, strlen(cp)+1);
+ found = 1;
+ break;
+ }
+ }
+ }
+ }
+ }
+ }
+ /* chop right blanks .. and see if term it gets empty */
+ if (p->u.t.term && csw->removed_items)
+ {
+ char *cp = p->u.t.term + strlen(p->u.t.term);
+ while (1)
+ {
+ if (cp == p->u.t.term)
+ {
+ /* term is empty / blank */
+ ccl_rpn_delete(p);
+ return 0;
+ }
+ if (!strchr(csw->blank_chars, cp[-1]))
+ break;
+ /* chop right */
+ cp[-1] = 0;
+ --cp;
+ }
+ }
+ break;
+ }
+ return p;
+}
+
+int ccl_stop_words_tree(ccl_stop_words_t csw,
+ CCL_bibset bibset, struct ccl_rpn_node **t)
+{
+ struct ccl_rpn_node *r;
+
+ /* remove list items */
+ nmem_reset(csw->nmem);
+ csw->removed_items = 0;
+
+ r = ccl_remove_stop_r(csw, bibset, *t);
+ *t = r;
+ if (csw->removed_items)
+ return 1;
+ return 0;
+}
+
+int ccl_stop_words_info(ccl_stop_words_t csw, int idx,
+ const char **qualname, const char **term)
+{
+ struct ccl_stop_info *csi = csw->removed_items;
+ int i = 0;
+ while (csi && i < idx)
+ {
+ csi = csi->next;
+ i++;
+ }
+ if (csi)
+ {
+ *qualname = csi->qualname;
+ *term = csi->term;
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+