6.19.6. Whitespace

As in the Haskell Language Report, Haskell comments are valid whitespace. In addition, lines (which must end with a line feed character) that begin as follows are valid whitespace in source code, except immediately after a where, let, do or of keyword:

• #!. This accommodates ‘shebang’ interpreter directives in scripts on Unix-like operating systems.
• <space>#!, where <space> is an initial space character before the ‘shebang’.
• #pragma. This accommodates the use of a directive that passes additional information to a compiler.
• #line <line> "<file>", where <line> is a positive integer and <file> can comprise zero or more characters. This accommodates a compiler directive that resets the numbering of lines of source code, and the identification of the source code file name, in compiler messages.
• #<line> "<file>", where <line> is a positive integer and <file> can comprise zero or more characters.