```excitedColumnsGenerator()``` Method in Java

Snippet.java

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 * Numenta Platform for Intelligent Computing (NuPIC)
 * Copyright (C) 2016, Numenta, Inc.  Unless you have an agreement
 * with Numenta, Inc., for a separate license for this software code, the
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 * published by the Free Software Foundation.
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero Public License for more details.
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package org.numenta.nupic.util;

import java.util.List;

import org.numenta.nupic.Connections;
import org.numenta.nupic.model.Column;
import org.numenta.nupic.model.DistalDendrite;


/**
 * Just a snippet to contain the method {@link #excitedColumnsGenerator(List, List, List, Connections)}
 * @author cogmission
 */
public class Snippet {
    
    
    private Generator<NamedTuple> excitedColumnsGenerator(
        List<Column> activeColumns, List<DistalDendrite> activeSegments, List<DistalDendrite> matchingSegments,
            Connections connections) {
        
        return new AbstractGenerator<NamedTuple>() {
            int activeColumnsProcessed = 0;
            int activeSegmentsProcessed = 0;
            int matchingSegmentsProcessed = 0;

            int activeColumnsNum = activeColumns.size();
            int activeSegmentsNum = activeSegments.size();
            int matchingSegmentsNum = matchingSegments.size();
            
            boolean isActiveColumn;
            
            @Override
            public void exec() {
                while((activeColumnsProcessed < activeColumnsNum ||
                      activeSegmentsProcessed < activeSegmentsNum ||
                      matchingSegmentsProcessed < matchingSegmentsNum) && !haltRequested()) {
                    
                    int currentColumn = Integer.MAX_VALUE;
                    if(activeSegmentsProcessed < activeSegmentsNum) {
                        currentColumn = Math.min(
                            currentColumn, 
                            activeSegments.get(activeSegmentsProcessed).getPresynapticColumnIndex());
                    }
                    
                    if(matchingSegmentsProcessed < matchingSegmentsNum) {
                        currentColumn = Math.min(
                            currentColumn,
                            matchingSegments.get(matchingSegmentsProcessed).getPresynapticColumnIndex());
                    }
                    
                    if(activeColumnsProcessed < activeColumnsNum &&
                        activeColumns.get(activeColumnsProcessed).getIndex() <= currentColumn) {
                        
                        currentColumn = activeColumns.get(activeColumnsProcessed).getIndex();
                        isActiveColumn = true;
                        activeColumnsProcessed += 1;
                    } else {
                        isActiveColumn = false;
                    }
                    
                    int activeSegmentsBegin = activeSegmentsProcessed;
                    int activeSegmentsEnd = activeSegmentsProcessed;
                    for(int i = activeSegmentsProcessed;i < activeSegmentsNum;i++) {
                        if(activeSegments.get(i).getPresynapticColumnIndex() == currentColumn) {
                            activeSegmentsProcessed += 1;
                            activeSegmentsEnd += 1;
                        } else {
                            break;
                        }
                    }
                    
                    int matchingSegmentsBegin = matchingSegmentsProcessed;
                    int matchingSegmentsEnd = matchingSegmentsProcessed;
                    for(int i = matchingSegmentsProcessed;i < matchingSegmentsNum;i++) {
                        if(matchingSegments.get(i).getPresynapticColumnIndex() == currentColumn) {
                            matchingSegmentsProcessed += 1;
                            matchingSegmentsEnd += 1;
                        } else {
                            break;
                        }
                    }
                    
                    Generator<Integer> asIndexGenerator = IntGenerator.of(activeSegmentsBegin, activeSegmentsEnd);
                    Generator<Integer> msIndexGenerator = IntGenerator.of(matchingSegmentsBegin, matchingSegmentsEnd);
                    yield(
                        new NamedTuple(
                            new String[] { 
                                "column", 
                                "isActiveColumn",
                                "activeSegments", 
                                "activeSegmentsCount", 
                                "matchingSegments", 
                                "matchingSegmentsCount" 
                            },
                            currentColumn, 
                            isActiveColumn, 
                            SegmentGenerator.of(activeSegments, asIndexGenerator), 
                            activeSegmentsEnd - activeSegmentsBegin,
                            SegmentGenerator.of(matchingSegments, msIndexGenerator),
                            matchingSegmentsEnd - matchingSegmentsBegin
                        )
                    );
                }
            }

            @Override
            public boolean isConsumed() {
                return activeColumnsProcessed >= activeColumnsNum &&
                       activeSegmentsProcessed >= activeSegmentsNum &&
                       matchingSegmentsProcessed >= matchingSegmentsNum;
            }
        };
    }
}