Add a CaseSensitive parameter to synonym dictionaries.

Simon Riggs

diff --git a/doc/src/sgml/textsearch.sgml b/doc/src/sgml/textsearch.sgml
index e484ddcbdcd3cd56600b3db403ce0c1a3814686b..1aec17efd97f0b4eea55ce5516651923d0cb9f9e 100644 (file)
--- a/doc/src/sgml/textsearch.sgml
+++ b/doc/src/sgml/textsearch.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/textsearch.sgml,v 1.41 2008/03/04 03:17:18 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/textsearch.sgml,v 1.42 2008/03/10 03:01:28 tgl Exp $ -->
 
 <chapter id="textsearch">
  <title id="textsearch-title">Full Text Search</title>
@@ -2209,7 +2209,8 @@ SELECT ts_lexize('public.simple_dict','The');
     dictionary can be used to overcome linguistic problems, for example, to
     prevent an English stemmer dictionary from reducing the word 'Paris' to
     'pari'.  It is enough to have a <literal>Paris paris</literal> line in the
-    synonym dictionary and put it before the <literal>english_stem</> dictionary:
+    synonym dictionary and put it before the <literal>english_stem</>
+    dictionary.  For example:
 
 <programlisting>
 SELECT * FROM ts_debug('english', 'Paris');
@@ -2242,10 +2243,17 @@ SELECT * FROM ts_debug('english', 'Paris');
     <productname>PostgreSQL</> installation's shared-data directory).
     The file format is just one line
     per word to be substituted, with the word followed by its synonym,
-    separated by white space.  Blank lines and trailing spaces are ignored,
-    and upper case is folded to lower case.
+    separated by white space.  Blank lines and trailing spaces are ignored.
    </para>
 
+   <para>
+    The <literal>synonym</> template also has an optional parameter
+    <literal>CaseSensitive</>, which defaults to <literal>false</>.  When
+    <literal>CaseSensitive</> is <literal>false</>, words in the synonym file
+    are folded to lower case, as are input tokens.  When it is
+    <literal>true</>, words and tokens are not folded to lower case,
+    but are compared as-is.
+   </para>
   </sect2>
 
   <sect2 id="textsearch-thesaurus">

diff --git a/src/backend/tsearch/dict_synonym.c b/src/backend/tsearch/dict_synonym.c
index 16eec98d8b2ba0847460996bfad5dfc7e7e3c7a6..6f263603d7a3900fb02acf3474ba58496fbbeaef 100644 (file)
--- a/src/backend/tsearch/dict_synonym.c
+++ b/src/backend/tsearch/dict_synonym.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/tsearch/dict_synonym.c,v 1.7 2008/01/01 19:45:52 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/tsearch/dict_synonym.c,v 1.8 2008/03/10 03:01:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,7 @@ typedef struct
 {
    int         len;            /* length of syn array */
    Syn        *syn;
+   bool        case_sensitive;
 } DictSyn;
 
 /*
@@ -77,6 +78,7 @@ dsynonym_init(PG_FUNCTION_ARGS)
    DictSyn    *d;
    ListCell   *l;
    char       *filename = NULL;
+   bool        case_sensitive = false;
    FILE       *fin;
    char       *starti,
               *starto,
@@ -90,6 +92,8 @@ dsynonym_init(PG_FUNCTION_ARGS)
 
        if (pg_strcasecmp("Synonyms", defel->defname) == 0)
            filename = defGetString(defel);
+       else if (pg_strcasecmp("CaseSensitive", defel->defname) == 0)
+           case_sensitive = defGetBoolean(defel);
        else
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -154,8 +158,16 @@ dsynonym_init(PG_FUNCTION_ARGS)
            }
        }
 
-       d->syn[cur].in = lowerstr(starti);
-       d->syn[cur].out = lowerstr(starto);
+       if (case_sensitive)
+       {
+           d->syn[cur].in = pstrdup(starti);
+           d->syn[cur].out = pstrdup(starto);
+       }
+       else
+       {
+           d->syn[cur].in = lowerstr(starti);
+           d->syn[cur].out = lowerstr(starto);
+       }
 
        cur++;
 
@@ -168,6 +180,8 @@ skipline:
    d->len = cur;
    qsort(d->syn, d->len, sizeof(Syn), compareSyn);
 
+   d->case_sensitive = case_sensitive;
+
    PG_RETURN_POINTER(d);
 }
 
@@ -185,7 +199,11 @@ dsynonym_lexize(PG_FUNCTION_ARGS)
    if (len <= 0 || d->len <= 0)
        PG_RETURN_POINTER(NULL);
 
-   key.in = lowerstr_with_len(in, len);
+   if (d->case_sensitive)
+       key.in = pnstrdup(in, len);
+   else
+       key.in = lowerstr_with_len(in, len);
+
    key.out = NULL;
 
    found = (Syn *) bsearch(&key, d->syn, d->len, sizeof(Syn), compareSyn);