change: lexer.lua has been moved to lib/lexer.lua.
add: lib/parser.lua has been added.
change: should separate helper symbol and command name.
fix: bug of the trimming patterns has been fixed.
fix: should increment index number of tags.
fix: bug of the trimming patterns.
add: lib/generator.lua has been added.
change: codebase improvement and some api interfaces has been changed.
change: rockspec has been updated.
change: example files has been updated.
change: README.md has been updated.