Syntax Analyzer

• Eliminate left recursion (both immediate and non-immediate {Algo on page 213 TB}) , left factoring (pg 215)
• Top down parser can't parse left recursive grammars.

Issues/Doubts

• A -> B | C me follow(A) includes follow(B) also ?
• No
• Are global variables allowed?
• No
• A declaration stmt can appear anywhere in the program. But everything according to grammar should be within a module
• cannot appear, variable declaratn in modules only
• print(arr[2]) not allowed in grammar {print only allows arr[ID] }
• is allowed , modify grammar accordingly
• get_value() does not allows to take arr[i]/arr[2] as input
• not allowed, only id allowed
• AND and OR have same precedence
• Arithmetic expressions grammar does not maintain precedence
• declare a:integer, b:real ; allowed? Grammar does not
• not allowed
• Function declarations saari ek saath upar hi ayengi?
• ha
• Function ke input parameters me array me variable indices allowed? {global variables toh hai hi, but grammar does not allows this}
• yes fun(int a, int b, arr[a..b]) syntactically valid
• array declaration ki grammar does not allow variable indices .. (whichID me ana chahiye instead of ID)
• 0 input parameters allowed in function definition? { grammar does not allows }
• not allowed
• idList,booleanExpr,inpList,outpList,artithmeticExpr,term, me left recursion
• TRUE/FALSE are boolean expressions or not?
• yes
• Left associativity hat jayegi when u remove left recursion.
• it can be implemented through right recursive grammar
• traversal ka tareeka change karna hoga
• Boolean expr rule is ambiguous
• switch(2 | arr[i] | arr[3] | {expression evaluating to a number} ) allowed or not
• not allowed, only id
• rule doesn't have any base case
• khud se daalo
• Language specification says 2 cases should be separated by a break, so last case me break rakhega kya?
• yes
• range me numop hoga kya?
• yes
• expr -> arith | bool
• left factoring hi hai

Tasks Left :

• Rule 30, 33 thik
• Sample test cases parse karne hai

Final Grammar with First and Follow Sets

Link