Created xcode project
Regex helper class for using NSRegularExpression. Swift doesn't support native regex...
added gitignore file
added some test files
Created Lexer class:  it allows to convert a sequence of characters in a swift file into a sequence of tokens.
Main swift file, it reads a file and user lexer and parse class to to all the work.
created AST nodes squeleton
created a bridging header to allow calling C++ from Swift (Bison parser is C/C++ code)
Implemented a scraper for the Swift Grammar rules. It parses oficial Swift Apple Documentation "Summary of the Grammar" which contains all the language rules. Then it translates the rules to bison C++ format. This scraper has been used to create the initial squeleton for the rules in the grammar.y file (with empty implementations and AST)
Initial version of the grammar rules (used the scraper to generate the rules)
Generated and added tokens to the bison grammar
Fixed grammar rules. Some auto generated optional rules where located on a invalid position
added program rule
make bison errors verbose
added debug declaration: this way bison prints the parser state when a conflict error is thrown
generated printfs to debug parser
Swift is a complex language that requires more than one symbol of lookahead, so we need to enable the generic LR parser on bison
improved scraper
Improved lexer: Created combined operators. The whitespace around an operator is used to determine whether an operator is used as a prefix operator, a postfix operator, or a binary operator.
Manually Improved rules for binary, prefix and postfix operators. Many shift/reduce and reduce/reduce conflicts avoided :)