Application: gvSIG desktop

package org.gvsig.expressionevaluator.impl.function.programming;

import java.util.HashMap;

import java.util.Map;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Code;

import org.gvsig.expressionevaluator.Codes;

import org.gvsig.expressionevaluator.Function;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

import static org.gvsig.expressionevaluator.ExpressionBuilder.FUNCTION_DICT;

import org.gvsig.expressionevaluator.Formatter;

public class DictFunction extends AbstractFunction {

    public DictFunction() {

        super(Function.GROUP_PROGRAMMING, 

                FUNCTION_DICT, 

                Range.between(0, Integer.MAX_VALUE),

                null,

                FUNCTION_DICT+"( {{identifier1}} = value1, identifier2 = value2, ...)",

                null,

                "Map",

                false

        );

    }

    @Override

    public boolean allowConstantFolding() {

        return false;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

      if( args.length==1 && args[0] instanceof Map) {

          return args[0];

      }

      Map<Object,Object> map = new HashMap<>();

      for (int i = 0; i < args.length; i+=2) {

        Object key = args[i];

        Object value = args[i+1];

        map.put(key, value);

      }

      return map;

    }

    @Override

    public String toString(Codes args, Formatter<Code> formatter) {

        StringBuilder builder = new StringBuilder();

        builder.append("{ ");

        boolean needcomma = false;

        for (int i = 0; i < args.size(); i+=2) {

          Code key = args.get(i);

          Code value = args.get(i+1);

          if( needcomma ) {

              builder.append(", ");

          } else {

              needcomma = true;

          }

          builder.append(key.toString(formatter));

          builder.append(":");

          builder.append(value.toString(formatter));

        }

        builder.append(" }");

        return builder.toString();

    }

}