/**
* Return type t such that values from both t1 and t2 can be assigned to t without loss of
* precision. Returns INVALID_TYPE if there is no such type or if any of t1 and t2 is
* INVALID_TYPE.
*/
public static ColumnType getAssignmentCompatibleType(ColumnType t1, ColumnType t2) {
if (!t1.isValid() || !t2.isValid()) return INVALID;
if (t1.equals(t2)) return t1;
if (t1.isDecimal() || t2.isDecimal()) {
if (t1.isNull()) return t2;
if (t2.isNull()) return t1;
// Allow casts between decimal and numeric types by converting
// numeric types to the containing decimal type.
ColumnType t1Decimal = t1.getMinResolutionDecimal();
ColumnType t2Decimal = t2.getMinResolutionDecimal();
if (t1Decimal.isInvalid() || t2Decimal.isInvalid()) return ColumnType.INVALID;
Preconditions.checkState(t1Decimal.isDecimal());
Preconditions.checkState(t2Decimal.isDecimal());
if (t1Decimal.isSupertypeOf(t2Decimal)) return t1;
if (t2Decimal.isSupertypeOf(t1Decimal)) return t2;
return TypesUtil.getDecimalAssignmentCompatibleType(t1Decimal, t2Decimal);
}
PrimitiveType smallerType = (t1.type_.ordinal() < t2.type_.ordinal() ? t1.type_ : t2.type_);
PrimitiveType largerType = (t1.type_.ordinal() > t2.type_.ordinal() ? t1.type_ : t2.type_);
PrimitiveType result = compatibilityMatrix[smallerType.ordinal()][largerType.ordinal()];
Preconditions.checkNotNull(result);
return createType(result);
}
/* Returns true if this decimal type is a supertype of the other decimal type.
* e.g. (10,3) is a super type of (3,3) but (5,4) is not a supertype of (3,0).
* To be a super type of another decimal, the number of digits before and after
* the decimal point must be greater or equal.
*/
public boolean isSupertypeOf(ColumnType o) {
Preconditions.checkState(isDecimal());
Preconditions.checkState(o.isDecimal());
if (isWildcardDecimal()) return true;
return scale_ >= o.scale_ && precision_ - scale_ >= o.precision_ - o.scale_;
}