/**
* Extracts the value from a literal.
*
* <p>Cases:
*
* <ul>
* <li>If the node is a character literal, a chain of string literals, or a CAST of a character
* literal, returns the value as a {@link NlsString}.
* <li>If the node is a numeric literal, or a negated numeric literal, returns the value as a
* {@link BigDecimal}.
* <li>If the node is a {@link SqlIntervalQualifier}, returns its {@link TimeUnitRange}.
* <li>If the node is INTERVAL_DAY_TIME in {@link SqlTypeFamily}, returns its sign multiplied by
* its millisecond equivalent value
* <li>If the node is INTERVAL_YEAR_MONTH in {@link SqlTypeFamily}, returns its sign multiplied
* by its months equivalent value
* <li>Otherwise the behavior is not specified.
* </ul>
*/
public static Comparable value(SqlNode node) {
if (node instanceof SqlLiteral) {
SqlLiteral literal = (SqlLiteral) node;
switch (literal.getTypeName().getFamily()) {
case CHARACTER:
return (NlsString) literal.value;
case NUMERIC:
return (BigDecimal) literal.value;
case INTERVAL_YEAR_MONTH:
final SqlIntervalLiteral.IntervalValue valMonth =
(SqlIntervalLiteral.IntervalValue) literal.value;
return valMonth.getSign() * SqlParserUtil.intervalToMonths(valMonth);
case INTERVAL_DAY_TIME:
final SqlIntervalLiteral.IntervalValue valTime =
(SqlIntervalLiteral.IntervalValue) literal.value;
return valTime.getSign() * SqlParserUtil.intervalToMillis(valTime);
}
}
if (SqlUtil.isLiteralChain(node)) {
assert node instanceof SqlCall;
final SqlLiteral literal = SqlLiteralChainOperator.concatenateOperands((SqlCall) node);
assert SqlTypeUtil.inCharFamily(literal.getTypeName());
return (NlsString) literal.value;
}
if (node instanceof SqlIntervalQualifier) {
SqlIntervalQualifier qualifier = (SqlIntervalQualifier) node;
return qualifier.timeUnitRange;
}
switch (node.getKind()) {
case CAST:
assert node instanceof SqlCall;
return value(((SqlCall) node).operand(0));
case MINUS_PREFIX:
assert node instanceof SqlCall;
Comparable o = value(((SqlCall) node).operand(0));
if (o instanceof BigDecimal) {
BigDecimal bigDecimal = (BigDecimal) o;
return bigDecimal.negate();
}
// fall through
default:
throw Util.newInternal("invalid literal: " + node);
}
}
/**
* Extracts the string value from a string literal, a chain of string literals, or a CAST of a
* string literal.
*
* @deprecated Use {@link #value(SqlNode)}
*/
@Deprecated // to be removed before 2.0
public static String stringValue(SqlNode node) {
if (node instanceof SqlLiteral) {
SqlLiteral literal = (SqlLiteral) node;
assert SqlTypeUtil.inCharFamily(literal.getTypeName());
return literal.toValue();
} else if (SqlUtil.isLiteralChain(node)) {
final SqlLiteral literal = SqlLiteralChainOperator.concatenateOperands((SqlCall) node);
assert SqlTypeUtil.inCharFamily(literal.getTypeName());
return literal.toValue();
} else if (node instanceof SqlCall
&& ((SqlCall) node).getOperator() == SqlStdOperatorTable.CAST) {
return stringValue(((SqlCall) node).operand(0));
} else {
throw Util.newInternal("invalid string literal: " + node);
}
}
public SqlNode visit(SqlLiteral literal) {
return (SqlNode) literal.clone();
}