com.pervasive.datarush.functions

Interface FunctionContext

public interface FunctionContext

Information about the context in which a function is evaluated. This information is passed to the FunctionTyper associated with the function to provide information necessary for performing type checks.

Method Summary

Methods

Modifier and Type	Method and Description
Object	getArgument(int i) Gets the specified argument.
int	getArgumentCount() Gets the number of arguments passed to the function.
ScalarTokenType	getArgumentType(int i) Gets the datatype of the specified argument.
String	getLabel() Gets the name of the function being evaluated.

Method Detail

getLabel

String getLabel()

Gets the name of the function being evaluated.

Returns:

the name associated with the function

getArgumentCount

int getArgumentCount()

Gets the number of arguments passed to the function.

Returns:

the number of function arguments

getArgumentType

ScalarTokenType getArgumentType(int i)

Gets the datatype of the specified argument.

In the context passed to FunctionTyper.computeUpperBound(FunctionContext), the returned type is the upper bound on the argument's type.

In the context passed to FunctionTyper.computeResultType(FunctionContext), the returned type is the actual type of the argument.

Parameters:

i - the index of the argument for which to get the type

Returns:

the type of the argument. If the argument is not a subtype of ScalarValuedFunction, null is returned.

getArgument

Object getArgument(int i)

Gets the specified argument.

Parameters:

i - the index of the argument to get

Returns:

the argument