DivDecimal
Related Doc:
package dpath
It is such a pain that there is no scala.math.Number base class above all the numeric types.
It is such a pain that there is no scala.math.Number base class above all the numeric types.
Division with rounding for decimals
About the rounding.
Without rounding specified here, you can get an java arithmetic exception Specifically:
What's questionable here, is to what number of fraction digits it will round. That can be specified also as an argument to divide(), but we have no information here (or anywhere really) about what precision is desired. So we're omitting that and just saying "round it".
Really, there's no rounding scale/precision until we're ready to represent the number in a string. In this case we're not. We're in the middle of an expression, just happen to have two BigDecimal operands, and we're dividing them, which should produce a BigDecimal result.
DFDL expressions are supposed to be consistent with XPath, so we look there for suggestions. The XPath spec https://www.w3.org/TR/xpath-functions-3/#op.numeric says it is implementation defined.
For xs:decimal values, let N be the number of digits of precision supported by the implementation, and let M (M <= N) be the minimum limit on the number of digits required for conformance (18 digits for XSD 1.0, 16 digits for XSD 1.1). Then for addition, subtraction, and multiplication operations, the returned result should be accurate to N digits of precision, and for division and modulus operations, the returned result should be accurate to at least M digits of precision. The actual precision is ·implementation-defined·. If the number of digits in the mathematical result exceeds the number of digits that the implementation retains for that operation, the result is truncated or rounded in an ·implementation-defined· manner
In our case, the implementation does what the JVM and java libraries do when divide() is called with two arguments the second of which specifies to round half-up.