Move functions to use ctype utils, cleanup

Author: michaelrj-google

libc/src/__support/ctype_utils.h

@@ -171,8 +171,67 @@ LIBC_INLINE static constexpr int tolower(int ch) {
   }
 }
 
+LIBC_INLINE static constexpr int toupper(int ch) {
+  switch (ch) {
+  case 'a':
+    return 'A';
+  case 'b':
+    return 'B';
+  case 'c':
+    return 'C';
+  case 'd':
+    return 'D';
+  case 'e':
+    return 'E';
+  case 'f':
+    return 'F';
+  case 'g':
+    return 'G';
+  case 'h':
+    return 'H';
+  case 'i':
+    return 'I';
+  case 'j':
+    return 'J';
+  case 'k':
+    return 'K';
+  case 'l':
+    return 'L';
+  case 'm':
+    return 'M';
+  case 'n':
+    return 'N';
+  case 'o':
+    return 'O';
+  case 'p':
+    return 'P';
+  case 'q':
+    return 'Q';
+  case 'r':
+    return 'R';
+  case 's':
+    return 'S';
+  case 't':
+    return 'T';
+  case 'u':
+    return 'U';
+  case 'v':
+    return 'V';
+  case 'w':
+    return 'W';
+  case 'x':
+    return 'X';
+  case 'y':
+    return 'Y';
+  case 'z':
+    return 'Z';
+  default:
+    return ch;
+  }
+}
+
 LIBC_INLINE static constexpr bool isalpha(int ch) {
-  switch (tolower(ch)) {
+  switch (ch) {
   case 'a':
   case 'b':
   case 'c':
@@ -199,18 +258,110 @@ LIBC_INLINE static constexpr bool isalpha(int ch) {
   case 'x':
   case 'y':
   case 'z':
+  case 'A':
+  case 'B':
+  case 'C':
+  case 'D':
+  case 'E':
+  case 'F':
+  case 'G':
+  case 'H':
+  case 'I':
+  case 'J':
+  case 'K':
+  case 'L':
+  case 'M':
+  case 'N':
+  case 'O':
+  case 'P':
+  case 'Q':
+  case 'R':
+  case 'S':
+  case 'T':
+  case 'U':
+  case 'V':
+  case 'W':
+  case 'X':
+  case 'Y':
+  case 'Z':
     return true;
   default:
     return false;
   }
 }
 
 LIBC_INLINE static constexpr bool isalnum(int ch) {
-  return isalpha(ch) || isdigit(ch);
+  switch (ch) {
+  case 'a':
+  case 'b':
+  case 'c':
+  case 'd':
+  case 'e':
+  case 'f':
+  case 'g':
+  case 'h':
+  case 'i':
+  case 'j':
+  case 'k':
+  case 'l':
+  case 'm':
+  case 'n':
+  case 'o':
+  case 'p':
+  case 'q':
+  case 'r':
+  case 's':
+  case 't':
+  case 'u':
+  case 'v':
+  case 'w':
+  case 'x':
+  case 'y':
+  case 'z':
+  case 'A':
+  case 'B':
+  case 'C':
+  case 'D':
+  case 'E':
+  case 'F':
+  case 'G':
+  case 'H':
+  case 'I':
+  case 'J':
+  case 'K':
+  case 'L':
+  case 'M':
+  case 'N':
+  case 'O':
+  case 'P':
+  case 'Q':
+  case 'R':
+  case 'S':
+  case 'T':
+  case 'U':
+  case 'V':
+  case 'W':
+  case 'X':
+  case 'Y':
+  case 'Z':
+  case '0':
+  case '1':
+  case '2':
+  case '3':
+  case '4':
+  case '5':
+  case '6':
+  case '7':
+  case '8':
+  case '9':
+    return true;
+  default:
+    return false;
+  }
 }
 
 LIBC_INLINE static constexpr int b36_char_to_int(int ch) {
-  switch (tolower(ch)) {
+  switch (ch) {
   case '0':
     return 0;
   case '1':
@@ -232,62 +383,171 @@ LIBC_INLINE static constexpr int b36_char_to_int(int ch) {
   case '9':
     return 9;
   case 'a':
+  case 'A':
     return 10;
   case 'b':
+  case 'B':
     return 11;
   case 'c':
+  case 'C':
     return 12;
   case 'd':
+  case 'D':
     return 13;
   case 'e':
+  case 'E':
     return 14;
   case 'f':
+  case 'F':
     return 15;
   case 'g':
+  case 'G':
     return 16;
   case 'h':
+  case 'H':
     return 17;
   case 'i':
+  case 'I':
     return 18;
   case 'j':
+  case 'J':
     return 19;
   case 'k':
+  case 'K':
     return 20;
   case 'l':
+  case 'L':
     return 21;
   case 'm':
+  case 'M':
     return 22;
   case 'n':
+  case 'N':
     return 23;
   case 'o':
+  case 'O':
     return 24;
   case 'p':
+  case 'P':
     return 25;
   case 'q':
+  case 'Q':
     return 26;
   case 'r':
+  case 'R':
     return 27;
   case 's':
+  case 'S':
     return 28;
   case 't':
+  case 'T':
     return 29;
   case 'u':
+  case 'U':
     return 30;
   case 'v':
+  case 'V':
     return 31;
   case 'w':
+  case 'W':
     return 32;
   case 'x':
+  case 'X':
     return 33;
   case 'y':
+  case 'Y':
     return 34;
   case 'z':
+  case 'Z':
     return 35;
   default:
     return 0;
   }
 }
 
+LIBC_INLINE static constexpr int int_to_b36_char(int num) {
+  // Can't actually use LIBC_ASSERT here because it depends on integer_to_string
+  // which depends on this.
+
+  // LIBC_ASSERT(num < 36);
+  switch (num) {
+  case 0:
+    return '0';
+  case 1:
+    return '1';
+  case 2:
+    return '2';
+  case 3:
+    return '3';
+  case 4:
+    return '4';
+  case 5:
+    return '5';
+  case 6:
+    return '6';
+  case 7:
+    return '7';
+  case 8:
+    return '8';
+  case 9:
+    return '9';
+  case 10:
+    return 'a';
+  case 11:
+    return 'b';
+  case 12:
+    return 'c';
+  case 13:
+    return 'd';
+  case 14:
+    return 'e';
+  case 15:
+    return 'f';
+  case 16:
+    return 'g';
+  case 17:
+    return 'h';
+  case 18:
+    return 'i';
+  case 19:
+    return 'j';
+  case 20:
+    return 'k';
+  case 21:
+    return 'l';
+  case 22:
+    return 'm';
+  case 23:
+    return 'n';
+  case 24:
+    return 'o';
+  case 25:
+    return 'p';
+  case 26:
+    return 'q';
+  case 27:
+    return 'r';
+  case 28:
+    return 's';
+  case 29:
+    return 't';
+  case 30:
+    return 'u';
+  case 31:
+    return 'v';
+  case 32:
+    return 'w';
+  case 33:
+    return 'x';
+  case 34:
+    return 'y';
+  case 35:
+    return 'z';
+  default:
+    return '!';
+  }
+}
+
 LIBC_INLINE static constexpr bool isspace(int ch) {
   switch (ch) {
   case ' ':