turn string into call for procedure?

[notAllCS]

I wondering if there is any way to use a string as a call to a procedure.

Ex.

procedure myProc

end myProc


var myName : string := "myProc"
% somehow turn "myProc" into myProc
myName


Thanks in advance for your help

[gitoxa]

Why would you want to?
Just make an if statement run the procedure when myName = "myProc"

[Zampano]

I'm supposing you want the user to be allowed to call code manually by passing a string which has the value of the name of a function or procedure. It's relies on the user of the client to know what procedures it's using. I don't think it can be done anyway. Even if it could, I think it would almost definitely be a bad idea.
What is the context where you want to do this?

[notAllCS]

Oh sorry. I forgot to mention that this is for a story book type game. There will be about 100 pages and so I don't want to have a massive if statement.

I'm hoping to somehow keep track of what the current page is and then allow the user to click on buttons "back" and "next" to 'turn the page'.

Given the integer page number, I'll have to somehow use that in a procedure call or a windowID

[Zampano]

I'm not exactly sure why you want this. Is it something like this:

code:

if a =  "forward" then        forward elsif a = "back" then        back end if

I can't think of a premise wherein you might need to perform many different things depending on many different conditions.

[notAllCS]

What if I want the user to pick a particular page in my 100 page storybook? Is the best way a massive "if"?

[CodeMonkey2000]

You should probably index your pages into an array. That way you can add/subtract 1 to your index holder, or just make it equal 100 or something. And when you have to draw it, just draw the page at the current index.

[Tony]

having 100 procedures for 100 pages is probably as good of an idea as having 100 if statements to access them.

Though CodeMonkey is right, you should use an array to index your pages (either data itself, or a reference to a procedure. That is, call procedure_one() with my_array[1]. An additional lookup table will allow you to map string values to integer indexes.

[rdrake]

I'd make each page an object, stick it in an array, then keep track of which page number you're on (which would then correspond to the position of that page in the array minus 1 since arrays are indexed from 0 normally). You'll then be able to call a procedure which every one of the objects have (since they come from the same class).

Just in case you're curious, it can be done in other languages like Ruby

Ruby:

irb(main):001:0> class Foo irb(main):002:1>   def bar irb(main):003:2>     "foobar" irb(main):004:2>   end irb(main):005:1> end => nil irb(main):006:0> f = Foo.new => #<Foo:0xb7ce44e4> irb(main):007:0> f.bar => "foobar" irb(main):008:0> s = "bar" => "bar" irb(main):009:0> f.send(s) => "foobar" irb(main):010:0>

[notAllCS]

Thanks. That will work.

[Vermette]

Just want to pass along that in other languages, doing what notAllCS asked is possible. It falls under the umbrella of metaprogramming. Definitely not necessary in this example, but still an interesting topic!

Here's some information to pique your interest:
http://en.wikipedia.org/wiki/Reflection_%28computer_science%29

[notAllCS]

Thanks. I knew that it was possible in other languages.

This is what we ended up doing:
currentPic := Pic.FileNew ("pics/gallery/gallery" + intstr (currentScreen) + ".JPG"

and using a picture for each screen