Changes between Version 193 and Version 194 of WikiStart

Timestamp:

06/26/19 08:19:19 (5 years ago)

Author:

wouter

Comment:

--

WikiStart

@@ -355 +355 @@
 }}}
 
-=== Value workaround
-This example also illustrates a problem with the json parser. In our jobs example domain, fte is a  discrete value, so "0.8" is just a string, not a number. However if fte would be a numeric issue, we naively would write the 0.8 without quotes: {{{fte:0.8}}}. However due to the way the json parser works, we would get 0.8 parsed as s double. This introduces rounding errors. And these cause all kinds of problems.
-
-To avoid these rounding errors, the solution is to store the decimal value also in a string. We can then later convert it properly. 
-
-However if we store it in a string, we would be unable to distinguish it from a discrete value. To work around this, we put it in a string and prepend it with a "=". 
-
-* "0.8": the DiscreteValue
-* "=0.8": the NumberValue.
-
-This workaround is only needed for issue values like in bids. In other places where we can *only* have double values, we can work around the issue without needing the string trick.
+Notice that in this example, issues like fte are discrete (possible values are enumerated). Therefore the issue value is double quoted. If the issue were numeric, we would write the issue value without quotes.