/**
* Implements a cast from any Java primitive to a nullable Java primitive as a simple
* assignment. i.e.
*
* <pre>
* [NullablePrimitiveType] lhs;
* lhs.[nullIndicator] = ...;
* if (! lhs.[nullIndicator]) {
* // check overflow ...
* // round ...
* lhs.[value] = ...;
* }
* </pre>
*/
private Expression castPrimitiveToNullablePrimitive() {
ensureLhs();
boolean nullableSource = rhsType.isNullable();
Expression rhsIsNull;
if (nullableSource) {
rhsIsNull = getNullIndicator(rhsExp);
rhsExp = getValue(rhsType, rhsExp);
} else {
rhsIsNull = Literal.constantFalse();
}
addStatement(assign(getNullIndicator(lhsExp), rhsIsNull));
StatementList setValueBlock = new StatementList();
StatementList oldList = borrowStmtList(setValueBlock);
try {
checkOverflow();
roundAsNeeded();
addStatement(assign(getValue(lhsType, lhsExp), new CastExpression(getLhsClass(), rhsExp)));
} finally {
returnStmtList(oldList);
}
if (nullableSource) {
addStatement(new IfStatement(not(getNullIndicator(lhsExp)), setValueBlock));
} else {
addStatementList(setValueBlock);
}
return lhsExp;
}
/**
* Gets the right hand expression as a valid value to be assigned to the left hand side. Usually
* returns the original rhs. However, if the lhs is of a primitive type, and the rhs is an
* explicit null, returns a primitive value instead.
*/
private Expression rhsAsValue() {
if (SqlTypeUtil.isJavaPrimitive(lhsType) && (rhsType.getSqlTypeName() == SqlTypeName.NULL)) {
if (lhsType.getSqlTypeName() == SqlTypeName.BOOLEAN) {
return Literal.constantFalse();
} else {
return Literal.constantZero();
}
}
return rhsExp;
}