The idea

The goal is to use command pattern and event sourcing. We model all state mutation methods as commands and register them in a stack. When the user hits undo button, we pop the first command and replay all the commands on the initial buffer. the popped command will be added to undo_stack. As for redo, we will pop the undo_stack and apply the command to the current buffer.

TODOs

• Refactor state->buffer into state->text_buffer and state->status_line_buffer.

• Clone text_buffer by value (cloning a 2d doubly linked list 😛 )

• undo_stack and history_stack