FUML12 — RealValue::toString puts too many digits in the mantissa

Specification: Semantics of a Foundational Subset for Executable UML Models (fUML), v1.1, RTF Beta (ptc/2012-10-18)
Subclause: 8.3.2.2.21 RealValue

The toString operation for RealValue is specified to determine the mantissa of a real number to 10 significant digits. It does this by scaling the (absolute value of) the real number and then converting it to an integer. Per the bUML representation in Annex B, the integer value is denoted as a Java int. Unfortunately, the upper bound of a Java int is 2,147,483,647, so some ten digit integers will overflow this value. While it is technically the UML semantics that apply to the specification here, via the Annex B mapping, not the Java semantics, it is still convenient (and intended) for the execution model operations to be able to run as Java methods, too. Therefore, it would be better to limit the mantissa to 9 digits rather than 10, so that the Java int representation of the mantissa never overflows.

Update RealValue::toString

Agreed.