szintaktikus elemzés

LL(1)
-----

1. egyszerű LL(1)
2. epszilonmentes LL(1)
3. általános LL(1)


S -> aAB | bSB
A -> b   | d
B -> aS  | bb


    a       b       d       #
S   (aAB,1) (bSB,2)
A           (b,3)   (d,4)
B   (aS,5)  (bb,6)
--------------------------------
a   pop
b           pop
d                   pop
#                           accept

abbb#

(abbb#, S#, []) ->          a/S: (aAB,1)
(abbb#, aAB#, [1]) ->       a/a: pop
(bbb#,  AB#, [1]) ->        b/A: (b,3)
(bbb#,  bB#, [1,3]) ->      b/b: pop
(bb#,   B#, [1,3]) ->       b/B: bb,6
(bb#,   bb#, [1,3,6]) ->    b/b: pop
(b#,    b#, [1,3,6]) ->     b/b: pop
(#,     #, [1,3,6]) ->      #/#: accept


    S -> aA
    A -> vS | eps

    S -> Sva | a


2. epszilonmentes LL(1)

S->AfA | De
A->B
B->a
D->d

    a       d       e       f       #
S   (AfA,1) (De,2)
A   (B,3)
B   (a,4)
D           (d,5)

FIRST
-----
FIRST(S)=FIRST(A) u FIRST(D)={a,d}
FIRST(A)=FIRST(B)={a}
FIRST(B)={a}
FIRST(D)={d}

S   AD      | d | ad
A   B       | a | a
B       a   | a | a
D       d   | d | d





S->AaB | Bb
A->DD  | d
B->bD  | f
D->e

FIRST
-----
S   AB      | dbf | dbfe | dbfe 
A   D   d   | de  | de   | de   
B       bf  | bf  | bf   | bf   
D       e   | e   | e    | e    

    a       b       d       e       f       #
S           (Bb,2)  (AaB,1) (AaB,1) (Bb,2)
A                   (d,4)   (DD,3)
B           (bD,5)                  (f,6)
D                           (e,7)






S->BDaD
B->ε   | b
D->ε   | d


S->AaB | Bb
A->DD  | d
B->hD  | f | ε
D->ε