org.apache.pig.piggybank.evaluation
Class IsNumeric

java.lang.Object
  extended by org.apache.pig.EvalFunc<Boolean>
      extended by org.apache.pig.piggybank.evaluation.IsNumeric

public class IsNumeric
extends EvalFunc<Boolean>

This UDF is used to check if a String is numeric. Note this UDF is different from IsInt in 2 ways, 1. Does not check for Integer range 2. Runs faster as this UDF uses Regex match and not Integer.parseInt(String) This UDF is expected to perform slightly better than isInt, isLong, isFloat, isDouble. However, primary goal of this UDF is NOT performance but rather to check "numeric"-ness of a String. Use this UDF if you do not care for the type (int, long, float, double) and would just like to check if its numeric in nature. It does NOT check for Range of int, long, double, parse. This function will return true when the String is larger than the range of any numeric data type (int, long, double, float). Use specific functions (IsInt, IsFloat, IsLong, IsDouble) if range is important.


Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.pig.EvalFunc
EvalFunc.SchemaType
 
Field Summary
 
Fields inherited from class org.apache.pig.EvalFunc
log, pigLogger, reporter, returnType
 
Constructor Summary
IsNumeric()
           
 
Method Summary
 Boolean exec(Tuple input)
          This callback method must be implemented by all subclasses.
 Schema outputSchema(Schema input)
          Report the schema of the output of this UDF.
 
Methods inherited from class org.apache.pig.EvalFunc
finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, isAsynchronous, progress, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warn
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

IsNumeric

public IsNumeric()
Method Detail

exec

public Boolean exec(Tuple input)
             throws IOException
Description copied from class: EvalFunc
This callback method must be implemented by all subclasses. This is the method that will be invoked on every Tuple of a given dataset. Since the dataset may be divided up in a variety of ways the programmer should not make assumptions about state that is maintained between invocations of this method.

Specified by:
exec in class EvalFunc<Boolean>
Parameters:
input - the Tuple to be processed.
Returns:
result, of type T.
Throws:
IOException

outputSchema

public Schema outputSchema(Schema input)
Description copied from class: EvalFunc
Report the schema of the output of this UDF. Pig will make use of this in error checking, optimization, and planning. The schema of input data to this UDF is provided.

The default implementation interprets the OutputSchema annotation, if one is present. Otherwise, it returns null (no known output schema).

Overrides:
outputSchema in class EvalFunc<Boolean>
Parameters:
input - Schema of the input
Returns:
Schema of the output


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