Sl and lr praser

1. NADAR SARASWATHI COLLEGE
OF ARTS AND SCIENCE THENI
SLR AND LR PARSER
M.shakthi
Msc( cs)

2. SLR PARSER:
•The SLR parser is simple to LR.
•It’s the smaller class of grammer
having few number of states.
•SLR is very easy to construct and is
similar to LR parser .

3. •The only difference between SLR parser
and LR parser is that in LR parsering table .
•There is a change of 'SHIFT REDUCED’
conflict because we are entering ‘reduced’
corresponding to all terminal states.
TYPES OF LR PARSERING METHODS:
1.SLR
2.CLR
3.LALR

4. STEPS FOR CONSTRUCTING SLR PARSERING
TABLE:
1.writing arguments grammer.
2.LR(O) collection of items to be found.
3.Find FOLLOW of LHS of production.
4.Defining 2 function:
GOTO( list of terminal)
ACTION(list of non terminal)

5. EXAMPLE
STEP1:
S—>AA
A-aA/b
S’-S(0th production)
S-.AA(1st production)
A-.aA(2nd production)
A-.b(3rd production )

6. STEP2:

7. STEP3:
Find follow of LHS of production
FOLLOW (s)=Ş
To find FOLLOW of non terminal.

8. STEP4:
Definiting 2 function
Goto, action.

9. LR PARSER:
It’s an efficient bottom up syntax analysis
techniques that can be used to parser language
classes of context free grammar is called LR(O)
parsing.
L stands for left to right scanning R stands for
rightmost derivation in reverse.
O stands for no of input symbols of looahead.

10. THANK YOU