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Character
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The members of the domain Character are values representing letters,
numerals and other text elements.

Characters can be obtained using String notation. ::

  chars := [char "a", char "A", char "X", char "8", char "+"]
   [a,A,X,8,+]
                      Type: List Character

Certain characters are available by name. This is the blank character. ::

  space()

                      Type: Character

This is the quote that is used in strings. ::

  quote()
   "
                      Type: Character

This is the escape character that allows quotes and other characters
within strings. ::

  escape()
   _
                      Type: Character

Characters are represented as integers in a machine-dependent way.
The integer value can be obtained using the ord operation.  It is
always true that char(ord c) = c and ord(char i) = i, provided that i
is in the range ``0..size()$Character-1``. ::

  [ord c for c in chars]
   [97,65,88,56,43]
                      Type: List Integer
 
The lowerCase operation converts an upper case letter to the
corresponding lower case letter.  If the argument is not an upper case
letter, then it is returned unchanged. ::

  [upperCase c for c in chars]
    [A,A,X,8,+]
                      Type: List Character

The upperCase operation converts lower case letters to upper case. ::

  [lowerCase c for c in chars]
   [a,a,x,8,+]
                      Type: List Character

A number of tests are available to determine whether characters
belong to certain families. ::

  [alphabetic? c for c in chars]
   [true,true,true,false,false]
                      Type: List Boolean

  [upperCase? c for c in chars]
   [false,true,true,false,false]
                      Type: List Boolean

  [lowerCase? c for c in chars]
    [true,false,false,false,false]
                      Type: List Boolean

  [digit? c for c in chars]
   [false,false,false,true,false]
                      Type: List Boolean

  [hexDigit? c for c in chars]
   [true,true,false,true,false]
                      Type: List Boolean

  [alphanumeric? c for c in chars]
   [true,true,true,true,false]
                      Type: List Boolean

See Also:

* ``)help CharacterClass``
* ``)help String``
* ``)show Character``