[AST] Infer type of the rule expression. Collapse tuple member of a sum inside the sum types. See #15.
[Refactoring] Move parsing classes in the front directory.
[Refactor] Bring rust syntax and compiler related names into the rust module.
[Refactor] Move semantics analysis into the middle directory.
[Refactor] Move compiler into the back directory.
[Refactor] Rename utility to identifier because it only contains name-related features.
[Refactor] No need to prefix with Peg, we know in which context we are. Peg -> Grammar and PegParser -> Parser.
[Lint] Add structure for lint and a grammar visitor.
[Refactor] Remove the expression-only visitor and use the new in undeclared rules checker.
[Attribute] Better print options and analysis of attributes. Creation of a specific module for attributes.