Linter rules and what they need from AST/CST to be implemented

[mangudai]

Linter rules and what they need from AST/CST to be implemented

[deltaidea]

Let's take a look at some rules and what they need.

eol-last — require or disallow newline at the end of files

• Access to the CST, because AST doesn't contain line breaks.
• A way to get the last token of the whole script and check whether it's a LineBreak.

no-redeclare — disallow constant and flag redeclaration

• Efficient way to visit all ConstDefinition and FlagDefinition nodes.
• Access to the CST representation of an AST node to report the offending text span.

no-trailing-spaces — disallow trailing whitespace at the end of lines

• Efficient way to visit all LineBreak CST nodes.

no-use-before-define — disallow the use of constants and flags before they are defined

• Efficient way to visit all places where identifiers can be used: command/attribute arguments and conditions.