us.bpsm.edn.parser.DefaultMapFactory Maven / Gradle / Ivy
// (c) 2012 B Smith-Mannschott -- Distributed under the Eclipse Public License
package us.bpsm.edn.parser;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
final class DefaultMapFactory implements CollectionBuilder.Factory {
public CollectionBuilder builder() {
return new CollectionBuilder() {
final Object none = new Object();
final Map map = new HashMap();
Object key = none;
public void add(Object o) {
if (key == none) {
key = o;
} else {
map.put(key, o);
key = none;
}
}
public Object build() {
if (key != none) {
throw new IllegalStateException(
"Every map must have an equal number of keys and values.");
}
return Collections.unmodifiableMap(map);
}
};
}
}