java/pig-galago/src/com/yahoo/pig/impl/eval/ConstEvalItem.java

   1 /*
   2  * Copyright (c) 2007 Yahoo! Inc.  All rights reserved.
   3  * See accompanying LICENSE file.
   4  */
   5 package com.yahoo.pig.impl.eval;
   6
   7 import java.io.IOException;
   8 import java.util.*;
   9
  10 import com.yahoo.pig.data.*;
  11 import com.yahoo.pig.impl.PigContext;
  12 import com.yahoo.pig.impl.logicalLayer.schema.SchemaField;
  13 import com.yahoo.pig.impl.logicalLayer.schema.SchemaItem;
  14 import com.yahoo.pig.impl.logicalLayer.schema.SchemaItemList;
  15
  16 final public class ConstEvalItem extends EvalItem {
  17     public String val;
  18     public Double dval  = null;
  19
  20     public ConstEvalItem(PigContext pigContext, String val) {
  21         super(pigContext);
  22         this.val = val;
  23     }
  24
  25     public String toString() {
  26         return "'" + val + "'";
  27     }
  28
  29     public List<String> getFuncs() {
  30         return new ArrayList<String>();
  31     }
  32
  33     public boolean isSimple() {
  34         return true;
  35     }
  36
  37     @Override
  38     public String stringVal(Tuple tup) throws IOException {
  39         return val;
  40     }
  41
  42     @Override
  43     public Double doubleVal(Tuple tup) throws IOException {
  44         if(dval == null) {
  45             try{
  46                 dval = Double.parseDouble(val);
  47             } catch(NumberFormatException exp) {
  48                 exp.printStackTrace();
  49             }
  50         }
  51         return dval;
  52     }
  53
  54     @Override
  55     public SchemaItem mapInputSchema(SchemaItem input){
  56         if (schema!= null)
  57                 return schema;
  58         return new SchemaField(null);
  59     }
  60
  61
  62     @Override
  63     public void eval(Tuple input, DataCollector output) throws IOException {
  64         output.add(new Tuple(new DataAtom(val)));
  65         output.add(null);  // EOF
  66     }
  67
  68     @Override
  69     public Datum simpleEval(Tuple input) throws IOException {
  70         return new DataAtom(val);
  71     }
  72
  73 }