format code and replace std function with Common utils.

src/Functions/soundex.cpp

@@ -2,11 +2,34 @@
 
 #include <Functions/FunctionFactory.h>
 #include <Functions/FunctionsHashing.h>
+#include <Common/StringUtils/StringUtils.h>
 
 
 namespace DB
 {
 
+/** The implementation of this algorithm is the same as most SQL language implementations.
+
+  * Soundex wiki: https://en.wikipedia.org/wiki/Soundex
+
+  * The details are as follows:
+
+  * 1. Save the first letter. Map all occurrences of a, e, i, o, u, y, h, w. to zero(0)
+  * 2. Replace all consonants (include the first letter) with digits as follows:
+  *
+  *  - b, f, p, v → 1
+  *  - c, g, j, k, q, s, x, z → 2
+  *  - d, t → 3
+  *  - l → 4
+  *  - m, n → 5
+  *  - r → 6
+  *
+  * 3. Replace all adjacent same digits with one digit, and then remove all the zero (0) digits
+  * 4. If the saved letter's digit is the same as the resulting first digit, remove the digit (keep the letter).
+  * 5. Append 3 zeros if result contains less than 3 digits. Remove all except first letter and 3 digits after it.
+  *
+  */
+
 struct SoundexImpl
 {
     static constexpr auto name = "soundex";
@@ -20,13 +43,13 @@ struct SoundexImpl
 
     static char getScode(const char *& ptr, const char * in_end)
     {
-        while (ptr < in_end && !std::isalpha(*ptr))
+        while (ptr < in_end && !isAlphaASCII(*ptr))
         {
-            (ptr)++;
+            ptr++;
         }
         if (ptr == in_end)
             return 0;
-        return soundex_map[std::toupper(*ptr) - 'A'];
+        return soundex_map[toUpperIfAlphaASCII(*ptr) - 'A'];
     }
 
     static void apply(const char * begin, const size_t size, unsigned char * out_char_data)
@@ -35,13 +58,13 @@ struct SoundexImpl
         const char * in_end = begin + size;
         unsigned char * out_end = out_char_data + length;
 
-        while (in_cur < in_end && !std::isalpha(*in_cur))
+        while (in_cur < in_end && !isAlphaASCII(*in_cur))
         {
             in_cur++;
         }
         if (in_cur < in_end)
         {
-            *out_char_data++ = std::toupper(*in_cur);
+            *out_char_data++ = toUpperIfAlphaASCII(*in_cur);
         }
         char last_ch = getScode(in_cur, in_end);