Lex concurrently starts lexing the given input and returns the associated Lexer instance.

*.

:.

,.

=.

sendData.

123.

{.

[.

(.

`rawstring`.

}.

].

).

Pos describes a position in a text file.

Token is an item returned from the scanner.

The Lexer interface represents a lexer that lexes its input into Tokens.

TokenType identifies the type of lex tokens.