In an LR parser, what is the purpose of the 'shift' action?
Practice Questions
Q1
In an LR parser, what is the purpose of the 'shift' action?
To reduce a production.
To push a state onto the stack.
To pop a state from the stack.
To accept the input.
Questions & Step-by-Step Solutions
In an LR parser, what is the purpose of the 'shift' action?
Step 1: An LR parser reads input symbols one by one from the input stream.
Step 2: When the parser encounters a symbol that it can use to build a part of the structure (like a part of a sentence), it performs the 'shift' action.
Step 3: The 'shift' action takes the current input symbol and moves it onto the stack.
Step 4: After shifting, the parser updates its state to reflect this new symbol on the stack.
Step 5: The parser then continues to read the next input symbol and decides whether to shift again or perform another action.
