ACSUtils implements functions from the C programming language's ctype.h. Only ASCII characters are supported.

• bool isalnum(int c) – returns true if the character is a letter or a digit.
• bool isalpha(int c) – returns true if the character is a letter.
• bool isblank(int c) – returns true if the character is blank.
• bool iscntrl(int c) – returns true if the character is a control character.
• bool isdigit(int c) – returns true if the character is a digit.
• bool isgraph(int c) – returns true if the character has a graphical representation.
• bool islower(int c) – returns true if the character is lowercase.
• bool isprint(int c) – returns true if the character is printable. Inverse of iscntrl().
• bool isprint(int c) – returns true if the character is a punctuation character.
• bool isspace(int c) – returns true if the character whitespace.
• bool isupper(int c) – returns true if the character is uppercase.
• bool isxdigit(int c) – returns true if the character is a hexadecimal digit (0123456789abcdef).

ACSUtils additions:

• bool isascii(int c) – returns true if the character is an ASCII character.

Character classification functions return false for all non-ASCII characters.

If the character is not a letter, these functions return the original character:

• int tolower(int c) – returns the lowercase version of the character.
• int toupper(int c) – returns the uppercase version of the character.

Non-ASCII characters are always returned without conversion.

These functions return true if all characters in the string match a character classification function:

• bool StrIsAscii(str s) – isascii
• bool StrIsAlnum(str s) – isalnum
• bool StrIsAlpha(str s) – isalpha
• bool StrIsBlank(str s) – isblank
• bool StrIsCntrl(str s) – iscntrl
• bool StrIsDigit(str s) – isdigit
• bool StrIsGraph(str s) – isgraph
• bool StrIsLower(str s) – islower
• bool StrIsPrint(str s) – isprint
• bool StrIsSpace(str s) – isspace
• bool StrIsUpper(str s) – isupper
• bool StrIsXDigit(str s) – isxdigit

These functions make all characters in the string lowercase or uppercase:

• str StrToLower(str s) – returns the string with all characters converted to lowercase.
• str StrToUpper(str s) – returns the string with all characters converted to uppercase.