Issue 17872: Reword isComputable (uml25-ftf)
Source: Nomos Software (Dr. Edward Willink, ed(at)willink.me.uk)
Nature: Clarification
Severity: 
Summary: This is woolly just redirecting to 'can be computed'.

Suggest: A ValueSpecification can be computed when all the algorithms, resources and values required to perform a computation are available. So a ValueSpecification would not be computable if an operation without a body was invoked, an off-line processor is required, or a source value is required. isComputable() is intended to be a static determination of capability, so a computation failure such as divide-by-zero or an I/O
failure would not prevent isComputable() returning true, rather they would cause a query
such as realValue() to return no value. 

?? if a computation needs a currently locked resource, is it computable? Probably yes, since if the computation waits patiently the result will appear ?? 

?? Should be three-valued...

True => a computation now will run
False => a computation now will abort
Null => a computation now might abort

Resolution: 
Revised Text: 
Actions taken:
September 26, 2012: received issue
Discussion: 

End of Annotations:=====
s is issue # 17872

Problem: 8.066

Severity: ?
Type: Clarification
Location: 8.6 p 100 isComputable()
Title: Reword isComputable
Discussion: 
 
This is woolly just redirecting to 'can be computed'.
 
Suggest: A ValueSpecification can be computed when all the algorithms, resources and values required to perform a computation are available. So a ValueSpecification would not be computable if an operation without a body was invoked, an off-line processor is required, or a source value is required. isComputable() is intended to be a static determination of capability, so a computation failure such as divide-by-zero or an I/O
failure would not prevent isComputable() returning true, rather they would cause a query
such as realValue() to return no value. 
 
?? if a computation needs a currently locked resource, is it computable? Probably yes, since if the computation waits patiently the result will appear ?? 
 
?? Should be three-valued...
 
True => a computation now will run
False => a computation now will abort
Null => a computation now might abort
 
Source: Edward Willink