public class SUBSTRING extends EvalFunc<String>
A = load 'mydata' as (name);
B = foreach A generate SUBSTRING(name, 10, 12);
First argument is the string to take a substring of.EvalFunc.SchemaType
log, pigLogger, reporter, returnType
Constructor and Description |
---|
SUBSTRING() |
Modifier and Type | Method and Description |
---|---|
boolean |
allowCompileTimeCalculation()
Whether the UDF should be evaluated at compile time if all inputs are constant.
|
String |
exec(Tuple input)
Method invoked on every tuple during foreach evaluation
|
List<FuncSpec> |
getArgToFuncMapping()
Allow a UDF to specify type specific implementations of itself.
|
Schema |
outputSchema(Schema input)
Report the schema of the output of this UDF.
|
finish, getCacheFiles, getInputSchema, getLoadCaster, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, needEndOfAllInputProcessing, progress, setEndOfAllInput, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warn
public String exec(Tuple input) throws IOException
exec
in class EvalFunc<String>
input
- tuple; first column is assumed to have the column to convertIOException
public Schema outputSchema(Schema input)
EvalFunc
The default implementation interprets the OutputSchema
annotation,
if one is present. Otherwise, it returns null
(no known output schema).
outputSchema
in class EvalFunc<String>
input
- Schema of the inputpublic List<FuncSpec> getArgToFuncMapping() throws FrontendException
EvalFunc
getArgToFuncMapping
in class EvalFunc<String>
FrontendException
public boolean allowCompileTimeCalculation()
EvalFunc
allowCompileTimeCalculation
in class EvalFunc<String>
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