Modula-3: Text and character literals

# Text and character literals

A character literal is a pair of single quotes enclosing either a single ISO-Latin-1 printing character (excluding single quote) or an escape sequence. The type of a character literal is `CHAR`.

A text literal is a pair of double quotes enclosing a sequence of ISO-Latin-1 printing characters (excluding double quote) and escape sequences. The type of a text literal is `TEXT`.

Here are are the legal escape sequences and the characters they denote:

        \n   newline (linefeed)     \f    form feed
        \t   tab                    \\    backslash
        \r   carriage return        \"    double quote
        \'   single quote           \nnn  char with code 8_nnn

A `\` followed by exactly three octal digits specifies the character whose code is that octal value. A `\` that is not a part of one of these escape sequences is a static error.

For example, `'a'` and `'\''` are valid character literals, `'''` is not; `""` and `"Don't\n"` are valid text literals, `"""` is not.

    Last modified on Wed Apr  3 09:38:54 PST 1996 by heydon
         modified on Mon Apr 18 13:39:16 PDT 1994 by kalsow