Compiler Design-Operator precedence parsing

Operator precedence parsing

Operator Precedence Parsing is applied to a small class of operators. It is similar to the shift-reduce Parsing method. 

It is said to be Operator Precedence parsing when it has the following two properties:

• R.H.S of any production a∊
• Two non-terminals should not be adjacent to each other.

Operator Precedence is only present or can be created between two terminals and the non-terminals are ignore.

Operator Precedence Relations:

1.  a<b: Meaning, terminal b has higher precedence than terminal a.
2.  a>b: Meaning, terminal a has higher precedence than terminal b.
3. a=b: Meaning, Both terminals have equal precedence.

Precedence Table: 

Parsing Action:

1. Add $ Symbol at both ends of the given input String.
2. Until encountered with ⋗ scan the input string from left to right.
3. Scan the leftover equal precedence to the first ⋖ is encountered.
4. Everything from leftmost ⋖ to the rightmost ⋗ handle.

Reference Link

Operator precedence parsing