On Tue, Apr 26, 2016 at 12:58 PM, Milan Bouchet-Valat <nalimi...@club.fr> 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 <arv.ka...@gmail.com> 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...
>
> 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
>> > >
>> > >
