1 files changed, 94 insertions, 0 deletions
diff --git a/src/func.c b/src/func.c
index 07c5069fc..36b0e5f37 100644
--- a/src/func.c
+++ b/src/func.c
@@ -966,6 +966,98 @@ static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
 }
 
 /*
+** tointeger(X):  If X is any value (integer, double, or string) that can
+** be losslessly converted into an integer, then make the conversion and
+** return the result.  Otherwise, return NULL.
+*/
+static void tointegerFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( argc==1 );
+  UNUSED_PARAMETER(argc);
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_FLOAT: {
+      double rVal = sqlite3_value_double(argv[0]);
+      i64 iVal = (i64)rVal;
+      if( rVal==(double)iVal ){
+        sqlite3_result_int64(context, iVal);
+      }
+      break;
+    }
+    case SQLITE_INTEGER: {
+      sqlite3_result_int64(context, sqlite3_value_int64(argv[0]));
+      break;
+    }
+    case SQLITE_BLOB:
+    case SQLITE_TEXT: {
+      const unsigned char *zStr = sqlite3_value_text(argv[0]);
+      if( zStr ){
+        int nStr = sqlite3_value_bytes(argv[0]);
+        if( nStr && !sqlite3Isspace(zStr[0]) ){
+          i64 iVal;
+          if( !sqlite3Atoi64((const char*)zStr, &iVal, nStr, SQLITE_UTF8) ){
+            sqlite3_result_int64(context, iVal);
+          }
+        }
+      }
+      break;
+    }
+    default: {
+      assert( sqlite3_value_type(argv[0])==SQLITE_NULL );
+      break;
+    }
+  }
+}
+
+/*
+** toreal(X):  If X can be losslessly converted into a real number, then
+** do so and return that real number.  Otherwise return NULL.
+*/
+static void torealFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( argc==1 );
+  UNUSED_PARAMETER(argc);
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_FLOAT: {
+      sqlite3_result_double(context, sqlite3_value_double(argv[0]));
+      break;
+    }
+    case SQLITE_INTEGER: {
+      i64 iVal = sqlite3_value_int64(argv[0]);
+      double rVal = (double)iVal;
+      if( iVal==(i64)rVal ){
+        sqlite3_result_double(context, rVal);
+      }
+      break;
+    }
+    case SQLITE_BLOB:
+    case SQLITE_TEXT: {
+      const unsigned char *zStr = sqlite3_value_text(argv[0]);
+      if( zStr ){
+        int nStr = sqlite3_value_bytes(argv[0]);
+        if( nStr && !sqlite3Isspace(zStr[0]) && !sqlite3Isspace(zStr[nStr-1]) ){
+          double rVal;
+          if( sqlite3AtoF((const char*)zStr, &rVal, nStr, SQLITE_UTF8) ){
+            sqlite3_result_double(context, rVal);
+            return;
+          }
+        }
+      }
+      break;
+    }
+    default: {
+      assert( sqlite3_value_type(argv[0])==SQLITE_NULL );
+      break;
+    }
+  }
+}
+
+/*
 ** The unicode() function.  Return the integer unicode code-point value
 ** for the first character of the input string. 
 */
@@ -1673,6 +1765,8 @@ void sqlite3RegisterGlobalFunctions(void){
     FUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
     FUNCTION(quote,              1, 0, 0, quoteFunc        ),
+    FUNCTION(tointeger,          1, 0, 0, tointegerFunc    ),
+    FUNCTION(toreal,             1, 0, 0, torealFunc       ),
     FUNCTION(last_insert_rowid,  0, 0, 0, last_insert_rowid),
     FUNCTION(changes,            0, 0, 0, changes          ),
     FUNCTION(total_changes,      0, 0, 0, total_changes    ),