Added TRIM, LTRIM, and RTRIM functions. (CVS 3698)

FossilOrigin-Name: 6fe13eeade4fc7099fbda1e6520640927c08debc

1 files changed, 82 insertions, 29 deletions

diff --git a/src/func.c b/src/func.c
index cfd377eeb..7850e22a1 100644
--- a/src/func.c
+++ b/src/func.c
@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.137 2007/03/17 13:27:55 drh Exp $
+** $Id: func.c,v 1.138 2007/03/17 17:52:42 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -697,12 +697,12 @@ static void replaceFunc(
       sqlite3_value_type(argv[2])==SQLITE_NULL ){
     return;
   }
-  nStr = sqlite3_value_bytes(argv[0]);
   zStr = sqlite3_value_text(argv[0]);
-  nPattern = sqlite3_value_bytes(argv[1]);
+  nStr = sqlite3_value_bytes(argv[0]);
   zPattern = sqlite3_value_text(argv[1]);
-  nRep = sqlite3_value_bytes(argv[2]);
+  nPattern = sqlite3_value_bytes(argv[1]);
   zRep = sqlite3_value_text(argv[2]);
+  nRep = sqlite3_value_bytes(argv[2]);
   if( nPattern>=nRep ){
     nOut = nStr;
   }else{
@@ -727,6 +727,55 @@ static void replaceFunc(
   sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
 }
 
+/*
+** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
+** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
+*/
+static void trimFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *zIn;         /* Input string */
+  const unsigned char *zCharSet;    /* Set of characters to trim */
+  int nIn;                          /* Number of bytes in input */
+  int flags;
+  int i;
+  unsigned char cFirst, cNext;
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
+    return;
+  }
+  zIn = sqlite3_value_text(argv[0]);
+  nIn = sqlite3_value_bytes(argv[0]);
+  if( argc==1 ){
+    static const unsigned char zSpace[] = " ";
+    zCharSet = zSpace;
+  }else if( sqlite3_value_type(argv[1])==SQLITE_NULL ){
+    return;
+  }else{
+    zCharSet = sqlite3_value_text(argv[1]);
+  }
+  cFirst = zCharSet[0];
+  if( cFirst ){
+    flags = (int)sqlite3_user_data(context);
+    if( flags & 1 ){
+      for(; nIn>0; nIn--, zIn++){
+        if( cFirst==zIn[0] ) continue;
+        for(i=1; zCharSet[i] && zCharSet[i]!=zIn[0]; i++){}
+        if( zCharSet[i]==0 ) break;
+      }
+    }
+    if( flags & 2 ){
+      for(; nIn>0; nIn--){
+        cNext = zIn[nIn-1];
+        if( cFirst==cNext ) continue;
+        for(i=1; zCharSet[i] && zCharSet[i]!=cNext; i++){}
+        if( zCharSet[i]==0 ) break;
+      }
+    }
+  }
+  sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
+}
 
 #ifdef SQLITE_SOUNDEX
 /*
@@ -1079,7 +1128,7 @@ static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv)
     ** Therefore the next statement sets variable 'max' to 1 for the max()
     ** aggregate, or 0 for min().
     */
-    max = ((sqlite3_user_data(context)==(void *)-1)?1:0);
+    max = sqlite3_user_data(context)!=0;
     cmp = sqlite3MemCompare(pBest, pArg, pColl);
     if( (max && cmp<0) || (!max && cmp>0) ){
       sqlite3VdbeMemCopy(pBest, pArg);
@@ -1109,15 +1158,15 @@ void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
   static const struct {
      char *zName;
      signed char nArg;
-     u8 argType;           /* 0: none.  1: db  2: (-1) */
+     u8 argType;           /* ff: db   1: 0, 2: 1, 3: 2,...  N:  N-1. */
      u8 eTextRep;          /* 1: UTF-16.  0: UTF-8 */
      u8 needCollSeq;
      void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
   } aFuncs[] = {
     { "min",               -1, 0, SQLITE_UTF8,    1, minmaxFunc },
     { "min",                0, 0, SQLITE_UTF8,    1, 0          },
-    { "max",               -1, 2, SQLITE_UTF8,    1, minmaxFunc },
-    { "max",                0, 2, SQLITE_UTF8,    1, 0          },
+    { "max",               -1, 1, SQLITE_UTF8,    1, minmaxFunc },
+    { "max",                0, 1, SQLITE_UTF8,    1, 0          },
     { "typeof",             1, 0, SQLITE_UTF8,    0, typeofFunc },
     { "length",             1, 0, SQLITE_UTF8,    0, lengthFunc },
     { "substr",             3, 0, SQLITE_UTF8,    0, substrFunc },
@@ -1139,23 +1188,29 @@ void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
     { "nullif",             2, 0, SQLITE_UTF8,    1, nullifFunc },
     { "sqlite_version",     0, 0, SQLITE_UTF8,    0, versionFunc},
     { "quote",              1, 0, SQLITE_UTF8,    0, quoteFunc  },
-    { "last_insert_rowid",  0, 1, SQLITE_UTF8,    0, last_insert_rowid },
-    { "changes",            0, 1, SQLITE_UTF8,    0, changes           },
-    { "total_changes",      0, 1, SQLITE_UTF8,    0, total_changes     },
+    { "last_insert_rowid",  0, 0xff, SQLITE_UTF8, 0, last_insert_rowid },
+    { "changes",            0, 0xff, SQLITE_UTF8, 0, changes           },
+    { "total_changes",      0, 0xff, SQLITE_UTF8, 0, total_changes     },
     { "replace",            3, 0, SQLITE_UTF8,    0, replaceFunc       },
+    { "ltrim",              1, 1, SQLITE_UTF8,    0, trimFunc          },
+    { "ltrim",              2, 1, SQLITE_UTF8,    0, trimFunc          },
+    { "rtrim",              1, 2, SQLITE_UTF8,    0, trimFunc          },
+    { "rtrim",              2, 2, SQLITE_UTF8,    0, trimFunc          },
+    { "trim",               1, 3, SQLITE_UTF8,    0, trimFunc          },
+    { "trim",               2, 3, SQLITE_UTF8,    0, trimFunc          },
 #ifdef SQLITE_SOUNDEX
-    { "soundex",            1, 0, SQLITE_UTF8, 0, soundexFunc},
+    { "soundex",            1, 0, SQLITE_UTF8,    0, soundexFunc},
 #endif
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
-    { "load_extension",     1, 1, SQLITE_UTF8,    0, loadExt },
-    { "load_extension",     2, 1, SQLITE_UTF8,    0, loadExt },
+    { "load_extension",     1, 0xff, SQLITE_UTF8, 0, loadExt },
+    { "load_extension",     2, 0xff, SQLITE_UTF8, 0, loadExt },
 #endif
 #ifdef SQLITE_TEST
-    { "randstr",               2, 0, SQLITE_UTF8, 0, randStr    },
-    { "test_destructor",       1, 1, SQLITE_UTF8, 0, test_destructor},
-    { "test_destructor_count", 0, 0, SQLITE_UTF8, 0, test_destructor_count},
-    { "test_auxdata",         -1, 0, SQLITE_UTF8, 0, test_auxdata},
-    { "test_error",            1, 0, SQLITE_UTF8, 0, test_error},
+    { "randstr",               2, 0,    SQLITE_UTF8, 0, randStr    },
+    { "test_destructor",       1, 0xff, SQLITE_UTF8, 0, test_destructor},
+    { "test_destructor_count", 0, 0,    SQLITE_UTF8, 0, test_destructor_count},
+    { "test_auxdata",         -1, 0,    SQLITE_UTF8, 0, test_auxdata},
+    { "test_error",            1, 0,    SQLITE_UTF8, 0, test_error},
 #endif
   };
   static const struct {
@@ -1167,7 +1222,7 @@ void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
     void (*xFinalize)(sqlite3_context*);
   } aAggs[] = {
     { "min",    1, 0, 1, minmaxStep,   minMaxFinalize },
-    { "max",    1, 2, 1, minmaxStep,   minMaxFinalize },
+    { "max",    1, 1, 1, minmaxStep,   minMaxFinalize },
     { "sum",    1, 0, 0, sumStep,      sumFinalize    },
     { "total",  1, 0, 0, sumStep,      totalFinalize    },
     { "avg",    1, 0, 0, sumStep,      avgFinalize    },
@@ -1177,10 +1232,12 @@ void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
   int i;
 
   for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
-    void *pArg = 0;
-    switch( aFuncs[i].argType ){
-      case 1: pArg = db; break;
-      case 2: pArg = (void *)(-1); break;
+    void *pArg;
+    u8 argType = aFuncs[i].argType;
+    if( argType==0xff ){
+      pArg = db;
+    }else{
+      pArg = (void*)(int)argType;
     }
     sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
         aFuncs[i].eTextRep, pArg, aFuncs[i].xFunc, 0, 0);
@@ -1199,11 +1256,7 @@ void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
   sqlite3AttachFunctions(db);
 #endif
   for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
-    void *pArg = 0;
-    switch( aAggs[i].argType ){
-      case 1: pArg = db; break;
-      case 2: pArg = (void *)(-1); break;
-    }
+    void *pArg = (void*)(int)aAggs[i].argType;
     sqlite3CreateFunc(db, aAggs[i].zName, aAggs[i].nArg, SQLITE_UTF8, 
         pArg, 0, aAggs[i].xStep, aAggs[i].xFinalize);
     if( aAggs[i].needCollSeq ){