src/rpn2cql.c

   1 /* This file is part of the YAZ toolkit.
   2  * Copyright (C) 1995-2008 Index Data
   3  * See the file LICENSE for details.
   4  */
   5
   6 /**
   7  * \file
   8  * \brief Implements RPN to CQL conversion
   9  *
  10  * Evaluation order of rules:
  11  *
  12  * always
  13  * relation
  14  * structure
  15  * position
  16  * truncation
  17  * index
  18  * relationModifier
  19  */
  20
  21 #include <assert.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <yaz/rpn2cql.h>
  25 #include <yaz/xmalloc.h>
  26 #include <yaz/diagbib1.h>
  27 #include <yaz/z-core.h>
  28 #include <yaz/wrbuf.h>
  29
  30 static int rpn2cql_simple(cql_transform_t ct,
  31                           void (*pr)(const char *buf, void *client_data),
  32                           void *client_data,
  33                           Z_Operand *q)
  34 {
  35     int ret = 0;
  36     if (q->which != Z_Operand_APT)
  37     {
  38         ret = -1;
  39         cql_transform_set_error(ct, YAZ_BIB1_RESULT_SET_UNSUPP_AS_A_SEARCH_TERM, 0);
  40     }
  41     else
  42     {
  43         Z_AttributesPlusTerm *apt = q->u.attributesPlusTerm;
  44         Z_Term *term = apt->term;
  45         Z_AttributeList *attributes = apt->attributes;
  46         WRBUF w = wrbuf_alloc();
  47
  48         switch(term->which)
  49         {
  50         case Z_Term_general:
  51             wrbuf_write(w, (const char *) term->u.general->buf, term->u.general->len);
  52             break;
  53         case Z_Term_numeric:
  54             wrbuf_printf(w, "%d", *term->u.numeric);
  55             break;
  56         case Z_Term_characterString:
  57             wrbuf_puts(w, term->u.characterString);
  58             break;
  59         default:
  60             ret = -1;
  61             cql_transform_set_error(ct, YAZ_BIB1_TERM_TYPE_UNSUPP, 0);
  62         }
  63         if (ret == 0)
  64             pr(wrbuf_cstr(w), client_data);
  65         wrbuf_destroy(w);
  66     }
  67     return ret;
  68 }
  69
  70 static int rpn2cql_structure(cql_transform_t ct,
  71                              void (*pr)(const char *buf, void *client_data),
  72                              void *client_data,
  73                              Z_RPNStructure *q, int nested)
  74 {
  75     if (q->which == Z_RPNStructure_simple)
  76         return rpn2cql_simple(ct, pr, client_data, q->u.simple);
  77     else
  78     {
  79         Z_Operator *op = q->u.complex->roperator;
  80         int r;
  81
  82         if (nested)
  83             pr("(", client_data);
  84
  85         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s1, 1);
  86         if (r)
  87             return r;
  88         switch(op->which)
  89         {
  90         case  Z_Operator_and:
  91             pr(" and ", client_data);
  92             break;
  93         case  Z_Operator_or:
  94             pr(" or ", client_data);
  95             break;
  96         case  Z_Operator_and_not:
  97             pr(" not ", client_data);
  98             break;
  99         case  Z_Operator_prox:
 100             cql_transform_set_error(ct, YAZ_BIB1_UNSUPP_SEARCH, 0);
 101             return -1;
 102         }
 103         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s2, 1);
 104         if (nested)
 105             pr(")", client_data);
 106         return r;
 107     }
 108 }
 109
 110 int cql_transform_rpn2cql(cql_transform_t ct,
 111                           void (*pr)(const char *buf, void *client_data),
 112                           void *client_data,
 113                           Z_RPNQuery *q)
 114 {
 115     cql_transform_set_error(ct, 0, 0);
 116     return rpn2cql_structure(ct, pr, client_data, q->RPNStructure, 0);
 117 }
 118
 119
 120 /*
 121  * Local variables:
 122  * c-basic-offset: 4
 123  * indent-tabs-mode: nil
 124  * End:
 125  * vim: shiftwidth=4 tabstop=8 expandtab
 126  */
 127