package dk.brics.string.stringoperations;
import dk.brics.automaton.Automaton;
import dk.brics.automaton.State;
import dk.brics.automaton.Transition;
import dk.brics.string.charset.CharSet;
import java.util.ArrayList;
import java.util.Set;
/**
* Automaton operation for {@link String#replace(char,char)} where only the first character is known.
*/
public class Replace2 extends UnaryOperation {
char c;
/**
* Automaton operation for {@link String#replace(char,char)} where only the first character is known.
* @param c the known value of the first argument.
*/
public Replace2(char c) {
this.c = c;
}
/**
* Automaton operation.
* Constructs new automaton as copy of <tt>a</tt> where all <tt>c</tt> transitions are changed
* to Sigma transitions.
*
* @param a input automaton
* @return resulting automaton
*/
@Override
public Automaton op(Automaton a) {
Automaton b = a.clone();
for (State s : b.getStates()) {
Set<Transition> transitions = s.getTransitions();
for (Transition t : new ArrayList<Transition>(transitions)) {
char min = t.getMin();
char max = t.getMax();
State dest = t.getDest();
if (min <= c && c <= max) {
transitions.add(new Transition(Character.MIN_VALUE, Character.MAX_VALUE, dest));
}
}
}
b.setDeterministic(false);
b.reduce();
b.minimize();
return b;
}
@Override
public String toString() {
return "replace2[" + Basic.escapeChar(c) + "]";
}
@Override
public int getPriority() {
return 5;
}
@Override
public CharSet charsetTransfer(CharSet a) {
if (a.contains(c)) {
return CharSet.makeAnychars();
} else {
return a;
}
}
@Override
public int hashCode() {
return getClass().hashCode() + c;
}
@Override
public boolean equals(Object obj) {
if (obj instanceof Replace2) {
Replace2 o = (Replace2) obj;
return c == o.c;
} else {
return false;
}
}
}