Pointer.java

package er.chronic.tags;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;

import er.chronic.Options;
import er.chronic.utils.Token;

public class Pointer extends Tag<Pointer.PointerType> {
  private static final Pattern IN_PATTERN = Pattern.compile("\\bin\\b");
  private static final Pattern FUTURE_PATTERN = Pattern.compile("\\bfuture\\b");
  private static final Pattern FOR_PATTERN = Pattern.compile("\\bfor\\b");
  private static final Pattern PAST_PATTERN = Pattern.compile("\\bpast\\b");

  public enum PointerType {
    PAST, FUTURE, NONE
  }
  
  public Pointer(Pointer.PointerType type) {
    super(type);
  }

  public static List<Token> scan(List<Token> tokens, Options options) {
    for (Token token : tokens) {
      Pointer t = Pointer.scanForAll(token, options);
      if (t != null) {
        token.tag(t);
      }
    }
    return tokens;
  }

  public static Pointer scanForAll(Token token, Options options) {
    Map<Pattern, Pointer.PointerType> scanner = new HashMap<>();
    scanner.put(Pointer.PAST_PATTERN, Pointer.PointerType.PAST);
    scanner.put(Pointer.FUTURE_PATTERN, Pointer.PointerType.FUTURE);
    scanner.put(Pointer.FOR_PATTERN, Pointer.PointerType.FUTURE);
    scanner.put(Pointer.IN_PATTERN, Pointer.PointerType.FUTURE);
    for (Pattern scannerItem : scanner.keySet()) {
      if (scannerItem.matcher(token.getWord()).matches()) { 
        return new Pointer(scanner.get(scannerItem));
      }
    }
    return null;
  }

  @Override
  public String toString() {
    return "pointer-" + getType();
  }
}