/**
* Returns a schema that matches all the number types that results by promoting the number types
* in the specified input schemata to a common type. If any input can be null, adds nullability.
* Returns null if inputs neither match null or any number.
*/
public static Schema promote(Schema s1, Schema s2) {
// check for nulls
boolean isNullable = s1.is(NULL).maybe() || s2.is(NULL).maybe();
s1 = SchemaTransformation.removeNullability(s1);
s2 = SchemaTransformation.removeNullability(s2);
if (s1 == null || s2 == null) {
return SchemaFactory.nullSchema();
}
// check for numeric types
boolean s1l = s1.is(JsonType.LONG).maybe();
boolean s1d = s1.is(JsonType.DOUBLE).maybe();
boolean s1m = s1.is(JsonType.DECFLOAT).maybe();
boolean s2l = s2.is(JsonType.LONG).maybe();
boolean s2d = s2.is(JsonType.DOUBLE).maybe();
boolean s2m = s2.is(JsonType.DECFLOAT).maybe();
if (!(s1l || s1d || s1m) || !(s2l || s2d || s2m)) return null; // non-number inputs
List<Schema> result = new ArrayList<Schema>(4);
if (s1l && s2l) {
result.add(SchemaFactory.longSchema());
}
if (((s1l || s1d) && s2d) || (s1d && (s2l || s2d))) {
result.add(SchemaFactory.doubleSchema());
}
if (s1m || s2m) {
result.add(SchemaFactory.decfloatSchema());
}
assert result.size() > 0;
if (isNullable) {
result.add(SchemaFactory.nullSchema());
}
return OrSchema.make(result);
}
@Override
public PathStepSchema getSchema(Schema inputSchema) {
Schema result = null;
if (indexExpr() instanceof ConstExpr) {
ConstExpr c = (ConstExpr) indexExpr();
JsonLong i = new JsonLong(((JsonNumber) c.value).longValueExact());
result = inputSchema.element(i);
if (result != null && inputSchema.hasElement(i).maybeNot()) {
result = SchemaTransformation.addNullability(result);
}
}
if (result == null) {
result = SchemaFactory.anySchema();
}
return nextStep().getSchema(result);
}