/**
* Finds an aggregate.
*
* @param node Parse tree to search
* @return First aggregate function in parse tree, or null if not found
*/
public SqlNode findAgg(SqlNode node) {
try {
node.accept(this);
return null;
} catch (Util.FoundOne e) {
Util.swallow(e, null);
return (SqlNode) e.getNode();
}
}
/** Clones a SqlNode with a different position. */
public SqlNode clone(SqlParserPos pos) {
// REVIEW jvs 26-July-2006: shouldn't pos be used here? Or are
// subclasses always supposed to override, in which case this
// method should probably be abstract?
try {
return (SqlNode) super.clone();
} catch (CloneNotSupportedException e) {
throw Util.newInternal(e, "error while cloning " + this);
}
}
/**
* Validates this node in an expression context.
*
* <p>Usually, this method does much the same as {@link #validate}, but a {@link SqlIdentifier}
* can occur in expression and non-expression contexts.
*/
public void validateExpr(SqlValidator validator, SqlValidatorScope scope) {
validate(validator, scope);
Util.discard(validator.deriveType(scope, this));
}
/**
* Creates a node.
*
* @param pos Parser position, must not be null.
*/
SqlNode(SqlParserPos pos) {
Util.pre(pos != null, "pos != null");
this.pos = pos;
}
public String getSignatureTemplate(final int operandsCount) {
Util.discard(operandsCount);
return "{1} {0} {2} AND {3}";
}