Question

1- Given the production:

S-> aSAb | Ab

A-> bbb

implement a complete pseudocode for a recursive descent parser. Assume scanner()

returns the next token.

2-

Given the production:

S-> aSAc | Acb

A-> bbb| empty

implement a complete pseudocode for a recursive descent parser. Assume scanner()

function returns the next token and error() aborting processing with an error

message. Do not forget the main program. This grammar is LL(1) so no need to check

nor modify.

Answer 1

S rightarrow aSAb/Ab A rightarrow bbb Let the ?Input string be - abbbbbbbb Recursive Decent passer would be - P seudocode Process S() { if input symbol = '0' then begin ADVACE (): if S () then if A () then if input symbol = 'b' then begin ADVANCE (): return tue: end els if begin if A () then if input symbol = 'b' then begin ADVANCE (): return True: end: end } return false: \r\n Procedure A () { if input symbol = 'b' then begin ADVANCE (): if input symbol = 'b' then begin ADVANCE (): if input symbol = 'b' then begin ADVANCE (): return true: end: else return false: end: else return false: end: else return false: \r\n (2) S rightarrow aSAc/Ach A rightarrow bbb/Empty Let Input string be - acbbbbc Pseudocode Procedure S () { if input symbol = '9' then