Input style

It is difficult to provide rules with substantial actions and still have a readable specification file. Here are a few style hints:

• Use all uppercase letters for token names and all lowercase letters for non-terminal names. This helps in debugging.

• Preface token names with an unusual sequence of characters, such as t_, to ensure that there are no conflicts with C reserved words.

• Put grammar rules and actions on separate lines to make the specification easier to read and edit.

• Put all rules with the same left side together. The left side should appear only once and each rule after the first one should begin with a vertical bar. Put the semicolon on a separate line after the last rule. This allows new rules to be added easily.

• Indent the body of a rule by one tab stop and the body of an action by two tab stops.

• Put complicated actions into subroutines.