Kapitel 4

Berechnung von nullable(X)
Compiler
Kapitel 4
Syntaktische Analyse
for all symbols X do
nullable(X) := false;
repeat
change := false;
true if k=0 !
for every production X → s 1 … s k
do
if nullable(X)=false and
s 1 … s k are all nullable then
{nullable(X) := true;
change := true;}
until change = false
Autor:
Aho et al.
Z → d Y→ ε X → Y
Z → XYZ Y→ c X → a