common string functions in BMAX?

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Gillissie

(Posted 2008) [#1]

I'm very experienced in programming, but brand new to BMax. I see that there are a bunch of string methods now, since strings are now technically objects. This is great, but I don't see a few basic methods like Left, Right, Mid. Is it correct to use these functions in the old-school format, or are they only there for backward compatibility with old BASIC code? It seems like they would be methods of the string type.

Brucey

(Posted 2008) [#2]

There's a BRL.Retro module which has those functions you are missing. They are 1 indexed.

The built-in methods (of String) use what's known as slicing. These are zero indexed.

For example :

Local s:String = "1234567890"

Print Left(s, 4)
Print s[..4]

Print Mid(s, 4, 3)
Print s[3..6]

Print Right(s, 4)
Print s[s.length - 4..]

See the (very short) guide on slicing in the IDE, if you want more information on that.
Slicing is a bit more efficient, since you are skipping a function call/return.

Gillissie

(Posted 2008) [#3]

Thanks Brucey. I actually noticed this stuff right after I posted that, but I could hardly believe the strangeness of it (especially the "Right" one). I mean, why not create string methods by these names that do the basic math for you and return the slices. Oh well.

Is there a way to add methods to an existing type? I'll do it myself if I can.

The way slices is implemented, it's not consistent.

[X..] means get the values starting with index X
[X..Y] means get values of index X-Y
[..X] means get the first X values (instead of values UP TO index X)

boomboom

(Posted 2008) [#4]

I believe if you want to add methods the best way is to extend the brl type and add new methods, eg:

Type My_TSound Extends TSound

Method NewMethod()

end method


End Type

Brucey

(Posted 2008) [#5]

String is not a "real" type, per se, and therefore you can't extend it. Think of it more as a primitive type than a... type type... :-p

TomToad

(Posted 2008) [#6]

[X..] means skip the first X elements and return the rest
[..X] means return the first X elements and skip the rest
[X..Y] means return the first Y elements after skipping the first X elements

One way to think about it that seems more consistent.