Add an optional 5th parameter to the next_char() function that is the

collating sequence to use for comparison.

FossilOrigin-Name: 9415db6ef255d27ca8473c17e65749a197c30455

ext/misc/nextchar.c

@@ -10,12 +10,22 @@
 **
 ******************************************************************************
 **
-** This file contains code to implement the next_char(A,T,F,W) SQL function.
+** This file contains code to implement the next_char(A,T,F,W,C) SQL function.
 **
-** The next_char(A,T,F,W) function finds all valid "next" characters for
+** The next_char(A,T,F,W,C) function finds all valid "next" characters for
-** string A given the vocabulary in T.F.  The T.F field should be indexed.
+** string A given the vocabulary in T.F.  If the W value exists and is a
-** If the W value exists and is a non-empty string, then it is an SQL
+** non-empty string, then it is an SQL expression that limits the entries
-** expression that limits the entries in T.F that will be considered.
+** in T.F that will be considered.  If C exists and is a non-empty string,
+** then it is the name of the collating sequence to use for comparison.  If
+** 
+** Only the first three arguments are required.  If the C parameter is 
+** omitted or is NULL or is an empty string, then the default collating 
+** sequence of T.F is used for comparision.  If the W parameter is omitted
+** or is NULL or is an empty string, then no filtering of the output is
+** done.
+**
+** The T.F column should be indexed using collation C or else this routine
+** will be quite slow.
 **
 ** For example, suppose an application has a dictionary like this:
 **
@@ -184,6 +194,9 @@ static void nextCharFunc(
   const unsigned char *zTable = sqlite3_value_text(argv[1]);
   const unsigned char *zField = sqlite3_value_text(argv[2]);
   const unsigned char *zWhere;
+  const unsigned char *zCollName;
+  char *zWhereClause = 0;
+  char *zColl = 0;
   char *zSql;
   int rc;
 
@@ -192,25 +205,41 @@ static void nextCharFunc(
   c.zPrefix = sqlite3_value_text(argv[0]);
   c.nPrefix = sqlite3_value_bytes(argv[0]);
   if( zTable==0 || zField==0 || c.zPrefix==0 ) return;
-  if( argc<4
+  if( argc>=4
-   || (zWhere = sqlite3_value_text(argv[3]))==0
+   && (zWhere = sqlite3_value_text(argv[3]))!=0
-   || zWhere[0]==0
+   && zWhere[0]!=0
   ){
-    zSql = sqlite3_mprintf(
+    zWhereClause = sqlite3_mprintf("AND (%s)", zWhere);
-        "SELECT \"%w\" FROM \"%w\""
+    if( zWhereClause==0 ){
-        " WHERE \"%w\">=(?1 || ?2)"
+      sqlite3_result_error_nomem(context);
-        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
+      return;
-        " ORDER BY 1 ASC LIMIT 1",
+    }
-        zField, zTable, zField, zField);
   }else{
-    zSql = sqlite3_mprintf(
+    zWhereClause = "";
-        "SELECT \"%w\" FROM \"%w\""
-        " WHERE \"%w\">=(?1 || ?2)"
-        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
-        "   AND (%s)"
-        " ORDER BY 1 ASC LIMIT 1",
-        zField, zTable, zField, zField, zWhere);
   }
+  if( argc>=5
+   && (zCollName = sqlite3_value_text(argv[4]))!=0
+   && zCollName[0]!=0 
+  ){
+    zColl = sqlite3_mprintf("collate \"%w\"", zCollName);
+    if( zColl==0 ){
+      sqlite3_result_error_nomem(context);
+      if( zWhereClause[0] ) sqlite3_free(zWhereClause);
+      return;
+    }
+  }else{
+    zColl = "";
+  }
+  zSql = sqlite3_mprintf(
+    "SELECT \"%w\" FROM \"%w\""
+    " WHERE \"%w\">=(?1 || ?2) %s"
+    "   AND \"%w\"<=(?1 || char(1114111)) %s" /* 1114111 == 0x10ffff */
+    "   %s"
+    " ORDER BY 1 %s ASC LIMIT 1",
+    zField, zTable, zField, zColl, zField, zColl, zWhereClause, zColl
+  );
+  if( zWhereClause[0] ) sqlite3_free(zWhereClause);
+  if( zColl[0] ) sqlite3_free(zColl);
   if( zSql==0 ){
     sqlite3_result_error_nomem(context);
     return;
@@ -261,5 +290,9 @@ int sqlite3_nextchar_init(
     rc = sqlite3_create_function(db, "next_char", 4, SQLITE_UTF8, 0,
                                  nextCharFunc, 0, 0);
   }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "next_char", 5, SQLITE_UTF8, 0,
+                                 nextCharFunc, 0, 0);
+  }
   return rc;
 }

manifest

@@ -1,5 +1,5 @@
-C Fixes\sfor\stest\scases\srunning\sin\sthe\s"mmap"\spermutation.
+C Add\san\soptional\s5th\sparameter\sto\sthe\snext_char()\sfunction\sthat\sis\sthe\ncollating\ssequence\sto\suse\sfor\scomparison.
-D 2013-07-06T18:07:57.900
+D 2013-07-08T01:27:43.173
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -110,7 +110,7 @@ F ext/misc/amatch.c eae8454cd9dcb287b2a3ec2e65a865a4ac5f0d06
 F ext/misc/closure.c 997c20ddf35f85ab399f4a02a557a9baa822ec32
 F ext/misc/fuzzer.c 136533c53cfce0957f0b48fa11dba27e21c5c01d
 F ext/misc/ieee754.c b0362167289170627659e84173f5d2e8fee8566e
-F ext/misc/nextchar.c 51c0abfa91009f736eb55d00452770df0ea09c3b
+F ext/misc/nextchar.c 80ba262d23238efcfcb3d72d71aa4513098e26a6
 F ext/misc/percentile.c bcbee3c061b884eccb80e21651daaae8e1e43c63
 F ext/misc/regexp.c c25c65fe775f5d9801fb8573e36ebe73f2c0c2e0
 F ext/misc/rot13.c 1ac6f95f99b575907b9b09c81a349114cf9be45a
@@ -793,7 +793,7 @@ F test/speed3.test d32043614c08c53eafdc80f33191d5bd9b920523
 F test/speed4.test abc0ad3399dcf9703abed2fff8705e4f8e416715
 F test/speed4p.explain 6b5f104ebeb34a038b2f714150f51d01143e59aa
 F test/speed4p.test 0e51908951677de5a969b723e03a27a1c45db38b
-F test/spellfix.test bea537caf587df30d430c2c6a8fe9f64b8712834
+F test/spellfix.test 38246facf7d9d7eeb8a57d7497cf7ce73ce5785d
 F test/sqllimits1.test b1aae27cc98eceb845e7f7adf918561256e31298
 F test/stat.test be8d477306006ec696bc86757cfb34bec79447ce
 F test/stmt.test 25d64e3dbf9a3ce89558667d7f39d966fe2a71b9
@@ -1101,7 +1101,7 @@ F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P 0ae7e75b215b0d75920769da9146c54ce2ad3ce0
+P cdb97d41abf4a3b8e22fa8ca9f3aab4a3f968d27
-R ca6d3b61d7033e8bd8885f323788dfc0
+R cddb399d89cded656ee0c42122eb620d
-U dan
+U drh
-Z 8857197c0df65b9e0d74b83df35e71c7
+Z 856ce6a2b43d394812cb00c43d8e6345

manifest.uuid

@@ -1 +1 @@
-cdb97d41abf4a3b8e22fa8ca9f3aab4a3f968d27
+9415db6ef255d27ca8473c17e65749a197c30455

test/spellfix.test

@@ -105,6 +105,22 @@ do_test 1.14 {
   catchsql {SELECT next_char('','xyzzy','a')}
 } {1 {no such table: xyzzy}}
 
+do_execsql_test 1.20 {
+  CREATE TABLE vocab2(w TEXT);
+  CREATE INDEX vocab2w ON vocab2(w COLLATE nocase);
+  INSERT INTO vocab2 VALUES('abc'), ('ABD'), ('aBe'), ('AbF');
+  SELECT next_char('ab', 'vocab2', 'w', null, 'nocase');
+} {cDeF}
+do_execsql_test 1.21 {
+  SELECT next_char('ab','vocab2','w',null,null);
+} {c}
+do_execsql_test 1.22 {
+  SELECT next_char('AB','vocab2','w',null,'NOCASE');
+} {cDeF}
+do_execsql_test 1.23 {
+  SELECT next_char('ab','vocab2','w',null,'binary');
+} {c}
+
 do_execsql_test 2.1 {
   CREATE VIRTUAL TABLE t2 USING spellfix1;
   INSERT INTO t2 (word, soundslike) VALUES('school', 'skuul');