Le mardi 26 avril 2016 à 13:22 -0400, Yichao Yu a écrit :
> On Tue, Apr 26, 2016 at 12:58 PM, Milan Bouchet-Valat wrote:
> >
> > Le mardi 26 avril 2016 à 12:52 -0400, Yichao Yu a écrit :
> > >
> > > On Tue, Apr 26, 2016 at 12:09 PM, Ali Rezaee <[email protected]> wrote:
> > > >
> > > >
> > > >
> > > > Thanks for your replies.
> > > > My objective is exactly what the code shows. I have a list of Boolean
> > > > expressions similar to the examples in the code, and I need to evaluate
> > > > them
> > > > one by one based on x values.
> > > > So writing a macro would be the only solution.
> > > Just to be clear, a macro can't help here. You need to eval in global
> > > scope if you want to evaluate arbitrary expressions.
> > Well, a macro could replace "x" with the name of the first argument,
> > create a function from that and call it.
> Well, I assume the string is runtime value so there's nothing a macro
> can do. If it is compile time value, then you might as well write the
> code directly instead of storing it in strings...
I assume these expressions come from an external file. We've seen a
similar scenario recently on this list.
Regards
> >
> > Though if possible creating anonymous functions is clearly a cleaner
> > solution.
> >
> >
> > Regards
> >
> > >
> > > >
> > > >
> > > >
> > > > Best regards
> > > >
> > > > On Tuesday, April 26, 2016 at 5:38:21 PM UTC+2, Ali Rezaee wrote:
> > > > >
> > > > >
> > > > >
> > > > > Hi everyone,
> > > > >
> > > > > I am trying to run the code below. When I try the code outside of a
> > > > > function and in REPL, it runs successfully. However when I run it
> > > > > using a
> > > > > function it throw an error.
> > > > > Why do I get the error? and how can I solve this problem?
> > > > >
> > > > > Thanks in advance for your help.
> > > > >
> > > > > rules = ["(x[1] && x[2])", "(x[3] || x[4])"]; # a list of boolean
> > > > > expressions
> > > > > boolList = [false, true, false, true]; # a boolean vector for every x
> > > > > in
> > > > > rules
> > > > >
> > > > > function evaluate(rules, boolList)
> > > > > x = boolList
> > > > > result = Array{Bool}(length(rules))
> > > > > for (i, rule) in enumerate(rules)
> > > > > result[i] = eval(parse(rule))
> > > > > end
> > > > > return result
> > > > > end
> > > > >
> > > > > evaluate(rules, boolList)
> > > > > # ERROR: UndefVarError: x not defined
> > > > >
> > > > > # but This will work:
> > > > > x = boolList
> > > > > result = Array{Bool}(length(rules))
> > > > > for (i, rule) in enumerate(rules)
> > > > > result[i] = eval(parse(rule))
> > > > > end
> > > > >
> > > > > result
> > > > > # 2-element Array{Bool,1}: false true
> > > > >
> > > > >
