Word Symbols

WordLiteral =
     Identifier |
     '"' { CharacterLiteral } '"'.

Each word symbol corresponds to a character string and is written as a sequence of character literals enclosed in double quotes. The character literals appearing in word symbols are the same as those appearing in character symbols. For example:

    "ABC"
    "123"
    "\"I don\'t like swimming!\" - said a little girl."

It should be noted that "ABC" represents a single word symbol, whereas 'ABC' represents the sequence of three character symbols. Besides, a word symbol consisting of a single character is regarded as different from the character symbol consisting of the same character. For example, the character symbol 'A' is different from the word symbol "A".

The double quotes enclosing a word symbol may be omitted, provided that the symbol satisfies the two following restrictions.

The word symbol may contain only the following characters: capital letters, small letters, digits, and underscores.
The first character of the word symbol must be either a capital letter or an underscore.

For example, here are two representations of the same word symbol:

    I_do_not_like_swimming
    "I_do_not_like_swimming"