[rules-users] DSL Entry Question

[Wolfgang Laun]

On 27 May 2011 16:24, jstroup <jstroup at regenstrief.org> wrote:

> Hi,
>
> The 5.2 docs list the following example DSL entry
>
>  [when][][Tt]here is an? {entity:\w+}=${entity!lc}: ${entity!ucfirst} ()
>
> Oops, there is a spurious '$', the second one. It should be
      =${entity!lc}: {entity!ucfirst} ()


> and say the following about what follows the equals sign
>
> "The remaining part of the line after the delimiting equal sign is the
> replacement text for any DSLR text matching the regular expression. It may
> contain variable references, i.e., a variable name enclosed in braces."
>
> What does the colon following the first variable do?


The colon in "...=${entity!lc}: {entity!ucfirst} ()" will remain a colon,
after expansion. It's the colon after a binding variable.




> Also, I'm used to (and actually understand) the following syntax which does
> not prefix { with a $.
>
>   [when]There is some {cheese} cheese available=Cheese(type=="{cheese}")
>

> My best guess is that the $ denotes a class name that is specified
> declaratively in the matching DSLR rule as opposed to a field {cheese} that
> is simply a replaceable parameter that matches whatever you type between
> "some" and "cheese available" and looks for Cheese objects of that type.
>
So,
> given the first DSL entry, if my rule text is
>
>  when
>
>    there is a cheese
>
> the rule will fire if a Cheese object has been inserted. And, conversely
>
>  when
>
>    There is an Cheese
>
> will also fire.
>

Since both expand to

    $cheese: Cheese ()



>
> Am I on the right track here?
>
>
yes, and thanks for the Q.
-W


> Thanks,
>
> Jeff
>
>
>
>
>
>
> --
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