/**
* Creates a key for {@link RexNode} which is the same as another key of another RexNode only if
* the two have both the same type and textual representation. For example, "10" integer and "10"
* bigint result in different keys.
*/
public static String makeKey(RexNode expr) {
String type = expr.getType().getFullTypeString();
String separator = ";";
String node = expr.toString();
StringBuilder keyBuilder =
new StringBuilder(type.length() + separator.length() + node.length());
keyBuilder.append(type).append(separator).append(node);
return keyBuilder.toString();
}
/**
* Computes a string describing this rule match. Two rule matches are equivalent if and only if
* their digests are the same.
*
* @return description of this rule match
*/
private String computeDigest() {
StringBuilder buf = new StringBuilder("rule [" + getRule() + "] rels [");
for (int i = 0; i < rels.length; i++) {
if (i > 0) {
buf.append(", ");
}
buf.append(rels[i].toString());
}
buf.append("]");
return buf.toString();
}