org.antlr.runtime.misc.DoubleKeyMap Maven / Gradle / Ivy
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A framework for constructing recognizers, compilers, and translators from grammatical descriptions containing Java, C#, C++, or Python actions.
package org.antlr.runtime.misc;
import java.util.*;
/** Sometimes we need to map a key to a value but key is two pieces of data.
* This nested hash table saves creating a single key each time we access
* map; avoids mem creation.
*/
public class DoubleKeyMap {
Map> data = new LinkedHashMap>();
public Value put(Key1 k1, Key2 k2, Value v) {
Map data2 = data.get(k1);
Value prev = null;
if ( data2==null ) {
data2 = new LinkedHashMap();
data.put(k1, data2);
}
else {
prev = data2.get(k2);
}
data2.put(k2, v);
return prev;
}
public Value get(Key1 k1, Key2 k2) {
Map data2 = data.get(k1);
if ( data2==null ) return null;
return data2.get(k2);
}
public Map get(Key1 k1) { return data.get(k1); }
/** Get all values associated with primary key */
public Collection values(Key1 k1) {
Map data2 = data.get(k1);
if ( data2==null ) return null;
return data2.values();
}
/** get all primary keys */
public Set keySet() {
return data.keySet();
}
/** get all secondary keys associated with a primary key */
public Set keySet(Key1 k1) {
Map data2 = data.get(k1);
if ( data2==null ) return null;
return data2.keySet();
}
public Collection values() {
Set s = new HashSet();
for (Map k2 : data.values()) {
for (Value v : k2.values()) {
s.add(v);
}
}
return s;
}
}