Next: Reserved Words
Up: Lexical Considerations
Case does not matter in Theta.
For example, "THEN", "then",
and "Then" are all the same reserved word.
A module is written as a sequence of tokens and separators.
A token is a sequence of ``printing'' ASCII characters representing a
reserved word, an identifier, a literal, an operator, or a punctuation
symbol. A separator is a ``blank'' character (a space,
vertical tab, horizontal tab, carriage return, newline, or form feed)
or a comment. Zero or more separators may appear between any two
tokens, where at least one separator is required between any two
adjacent non-self-terminating tokens: reserved words, identifiers,
integer literals, and real literals. Tokens are described in more
detail in the following sections.
A comment begins with a percent sign ("with the first ``line-ending'' character (a vertical tab, carriage
return, newline, or form feed). The enclosed characters serve as a
single separator and are otherwise ignored by the compiler.