org.eigenbase.sql.type
Interface SqlSingleOperandTypeChecker

All Superinterfaces:

SqlOperandTypeChecker

All Known Implementing Classes:

CompositeOperandTypeChecker, FamilyOperandTypeChecker, LiteralOperandTypeChecker

public interface SqlSingleOperandTypeChecker
extends SqlOperandTypeChecker

SqlSingleOperandTypeChecker is an extension of SqlOperandTypeChecker for implementations which are cabable of checking the type of a single operand in isolation. This isn't meaningful for all type-checking rules (e.g. SameOperandTypeChecker requires two operands to have matching types, so checking one in isolation is meaningless).

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/type/SqlSingleOperandTypeChecker.java#7 $

Author:

Wael Chatila

Method Summary

boolean

checkSingleOperandType(SqlCallBinding callBinding, SqlNode operand, int iFormalOperand, boolean throwOnFailure) Checks the type of a single operand against a particular ordinal position within a formal operator signature.

Methods inherited from interface org.eigenbase.sql.type.SqlOperandTypeChecker

checkOperandTypes, getAllowedSignatures, getOperandCountRange

Method Detail

checkSingleOperandType

boolean checkSingleOperandType(SqlCallBinding callBinding,
                               SqlNode operand,
                               int iFormalOperand,
                               boolean throwOnFailure)

Checks the type of a single operand against a particular ordinal position within a formal operator signature. Note that the actual ordinal position of the operand being checked may be different from the position of the formal operand.

For example, when validating the actual call

C(X, Y, Z)

the strategy for validating the operand Z might involve checking its type against the formal signature OP(W). In this case, iFormalOperand would be zero, even though the position of Z within call C is two.

Parameters:

callBinding - description of the call being checked; this is only provided for context when throwing an exception; the implementation should NOT examine the operands of the call as part of the check

operand - the actual operand to be checked

iFormalOperand - the 0-based formal operand ordinal

throwOnFailure - whether to throw an exception if check fails (otherwise returns false in that case)

Returns:

whether check succeeded