[Gambas-user] Custom Eval (was Re: The new Border class)

[Charlie Reinl]

Am Sonntag, den 08.02.2015, 14:46 +0100 schrieb Fabien Bodard:
> oups i missed for the first one :
> iResult = MyCol[eval("Sum_of_Value_page_" & CStr(Page_Nr), myCol)]
> 
> 2015-02-08 14:45 GMT+01:00 Fabien Bodard <gambas.fr at ...626...>:
> > ???
> > If I summarize  what i see I can answer :
> >
> > iResult = MyCol[eval(eval("Sum_of_Value_page_" & CStr(Page_Nr), myCol)]
> >
> > or simply
> >
> > iResult = MyCol["Sum_of_Value_page_" & CStr(MyCol["Page_Nr"])]
> >
> > Well if you have a point where you fill myCol so no need to store :
> >
> > iResult = MyCol["Sum_of_Value_page_" & iPage]
> >
> >
> > BUT ... I'm not sure it was the goal of your query, so please be more
> > precise or give an example. :-)
> >
> > 2015-02-07 22:41 GMT+01:00 Charlie Reinl <Karl.Reinl at ...9...>:
> >> Am Montag, den 05.01.2015, 22:16 +0100 schrieb Fabien Bodard:
> >>> 2015-01-05 22:02 GMT+01:00 Benoît Minisini <gambas at ...1...>:
> >>> > Le 05/01/2015 21:46, Fabien Bodard a écrit :
> >>> >>> What do you mean?
> >>> >>>
> >>> >>> --
> >>> >>> Benoît Minisini
> >>> >>
> >>> >> I think about a tool that will be able to interpret inline formulas
> >>> >> like in a spreedsheet.
> >>> >>
> >>> >> i have done something like that for playing myself but i'm not a
> >>> >> specialist of interpreters like you.
> >>> >>
> >>> >> for example :
> >>> >>
> >>> >> =Myvar1 + 3 *(3*myvar2)
> >>> >> =MYFUNCTION(myvar1; myvar2) + MyVar3
> >>> >>
> >>> >> the function can be initialised for example like
> >>> >>
> >>> >> Interpret.Function.Add("MYFunction", nbreArgs, typeRetVal)
> >>> >>
> >>> >> And will call Public Sub Interpret_MyFunction(Arg1 as variant, arg2 as
> >>> >> variant,...) as variant
> >>> >>
> >>> >> A Special Event will query the vars values : Public Sub
> >>> >> Interpret_GetVar(sVarName as string) as Variant
> >>> >>
> >>> >> All the stuff of the interpreter will be to manage conditionnal
> >>> >> requirement and calculate values  or concatenate strings. So this tool
> >>> >> will be usefull for user level programmation.
> >>> >> Like in spreadsheet or in reports formulas. It can be extended near to
> >>> >> unlimited. Some functions can be hardcoded like mathematical ones.
> >>> >> Others are depend of the context so must be implemented for each
> >>> >> widget or component. It's not the fastest way to make compute but the
> >>> >> most flexible.
> >>> >>
> >>> >> I hope my english is not inapprehensible
> >>> >>
> >>> >
> >>> > If I understand well, you need some sort of custom Eval().
> >>> >
> >>> > More precisely, I think what you need is a Gambas hook inside the reader
> >>> > part of Eval() (the first part of its internal compiler) where you tell
> >>> > how to translate any symbol into a Gambas function or a call to a method
> >>> > into one of your classes, everything else being forbidden.
> >>> >
> >>> > That way, you keep the Gambas syntax, except that all function names are
> >>> > redefined, and every interpreter class is forbidden except the one you
> >>> > allow explicitly.
> >>>
> >>> Yes it can be the idea. But can it be compatible with 'STANDARD'
> >>> formulas style too ? were separtors are ';'...
> >>>
> >>> But your idea will be a great step too and i think you have understand
> >>> the back of my mind.
> >>>
> >>>
> >>>
> >>> >
> >>> > Just an idea...
> >>> >
> >>> > --
> >>> > Benoît Minisini
> >>
> >> Salut Benoît,
> >>
> >> searching something for my problem, I found this mail. What I need is
> >> something you describe as "Gambas hook inside the reader part of
> >> Eval()".
> >> In my Collection passed to eval, I have "Sum_of_Value_page_1" to
> >> "Sum_of_Value_page_35"  and the "Page_Nr". Now for picking the right
> >> value I need the eval("Sum_of_Value_page_" & CStr(Page_Nr), myCol).
> >> Done like that, I get "Sum_of_Value_page_1" to "Sum_of_Value_page_35" as
> >> return. That is nice, but I want the result of that, stored in myCol.
> >>
> >> Thought I could resolve that with a public function called by eval
> >> failed also.
> >> "Public Function Sum(sFiledName as string) as Variant" isn't called.
> >>
> >> So I need that what you call "Gambas hook inside the reader part of
> >> Eval()".... Or something that works like I know from Clipper, called
> >> Code-Blocks. Search I-net for "clipper code blocks"
> >>
> >>
> >>
> >>
> >> --
> >> Amicalement
> >> Charlie

Salut Fabien,

thanks for your responding, but my problem is not, to get any results
out of a collection or I can't create the key out of a String + page.
My problem is that I can't do that with 'Eval' like it is actually.
To explain, I use eval for my 'computed fields'. Till now no problems
with. In the Collection, I use with Eval all what I need is stored.
So when I call Eval("Page_Nr", myCol) , I get a number. With
Eval("Sum_of_Value_page_2", myCol) I get the value stored behind that
key.
But with Eval("Sum_of_Value_page_" & CStr("Page_Nr"), myCol)  I get only
"Sum_of_Value_page_" & CStr("Page_Nr"). I'v tried varies things,
included evals etc, no way, for that I stepped into your feature
request.  
-- 
Amicalement
Charlie