package org.matheclipse.core.reflection.system;

import static org.matheclipse.core.expression.F.List;

import java.util.ArrayList;
import java.util.List;

import org.matheclipse.core.eval.EvalEngine;
import org.matheclipse.core.eval.interfaces.IFunctionEvaluator;
import org.matheclipse.core.eval.util.Iterator;
import org.matheclipse.core.eval.util.TableGenerator;
import org.matheclipse.core.generic.UnaryRangeFunction;
import org.matheclipse.core.interfaces.IAST;
import org.matheclipse.core.interfaces.IExpr;
import org.matheclipse.core.interfaces.ISymbol;

public class Range implements IFunctionEvaluator {

  public Range() {
  }

  public IExpr evaluate(final IAST ast) {
    return evaluateTable(ast, List());
  }

  public IExpr evaluateTable(final IAST ast, final IAST resultList) {
    List iterList = null;
    try {
      if ((ast.size() > 1) && (ast.size() <= 4)) {
        final EvalEngine engine = EvalEngine.get();
        iterList = new ArrayList();
        iterList.add(new Iterator(ast, null, engine));

        final TableGenerator generator = new TableGenerator(
            iterList, resultList, new UnaryRangeFunction());
        return generator.table();
      }
    } catch (final ClassCastException e) {
      // the iterators are generated only from IASTs
    } finally {
      if (iterList != null) {
        for (int i = 0; i < iterList.size(); i++) {
          iterList.get(i).tearDown();
        }
      }
    }
    return null;
  }

  public IExpr numericEval(final IAST functionList) {
    return evaluate(functionList);
  }

  public void setUp(final ISymbol symbol) {
    symbol.setAttributes(ISymbol.HOLDALL);
  }
}