LR parser

An lr parser is like a really clever robot that reads and understands a language that's been programmed into it. Let's pretend this robot is reading a book, but this book is written in a special language that the robot understands really well.

The robot starts by looking at the first sentence in the book. It tries to understand what it means by looking at the first few words. If it recognizes the words and knows what they mean, it moves on to the next words. If it doesn't understand a word, it looks it up in its language dictionary.

As the robot reads and understands more of the book, it starts building a tree of possible meanings for the words and sentences it's seen so far. Sometimes, a sentence can be read in more than one way, so the robot has to try to figure out which is the correct meaning by checking the rules of the language it's been programmed with.

Once the robot has finished reading the book, it will have built a complete "parse tree" that shows all the possible meanings for every sentence and word in the book. This is really useful for programmers because it helps them write computer programs that can read and understand languages just like this robot.

Overall, an lr parser is just a clever tool that helps computers read and understand languages. It's kind of like a smart robot that can read books and understand what they mean.