CHECKLIST
CONDITION(boolean logic)
CONDITION(boolean logic)
CONDITION(boolean logic)
CONDITION(boolean logic)
CONDITION(boolean logic)
CONDITION(boolean logic)
ON SUCCESS
END
ON FAIL
END
END
Does this exist in any language?
Author
I just came up with this, similar to a case statement. Kind of an alternative to nested IF statements.
Has anybody seen this before? Or did I just invent something...
Basically, the statement checks through each piece of boolean logic in the order they are presented. If all logics are true, the code within ON SUCCESS block exexcutes. On the first failure, code within ON FAIL block executes.
I've seen similar enough things done in C++ and C# via functor aggregation. I'd imagine functional languages do this sort of thing more often in their own style.
There are several languages that have this. For example:
Common Lisp:
Scheme:
Haskell:
It's called a guard in some languages (such as Haskell).
EDIT: I misread the OP. What you are talking about is a simple collection of and-statements.
[Edited by - Roboguy on August 2, 2007 11:58:13 PM]
Common Lisp:
(cond (condition1 ...) (condition2 ...) (condition3 ...) ... (t ...))Scheme:
(cond (condition1 ...) (condition2 ...) (condition3 ...) ... (else ...))Haskell:
fn arg1 arg2 ... argn | condition1 = expression1 | condition2 = expression2 | condition3 = expression3 ... | otherwise = expressionnIt's called a guard in some languages (such as Haskell).
EDIT: I misread the OP. What you are talking about is a simple collection of and-statements.
[Edited by - Roboguy on August 2, 2007 11:58:13 PM]
It's all semantics.
Replace "CHECK LIST" with "if", and replace most occurrences of "CONDITION" with "&&", etc.
Replace "CHECK LIST" with "if", and replace most occurrences of "CONDITION" with "&&", etc.
#define CHECKLIST { if(true#define CONDITION &&#define ON#define SUCCESS ) {#define END }#define FAIL else {
Or if you prefer...As a matter of fact I just used such a construct today
Of course I didn't use these defines to accomplish the task.
Edit: Missed the ON FAIL bit. Okay okay, so mine now doesn't work if you use it twice in the same function. That's what you get for using END to mean two different things.
#define CHECKLIST bool b=false; do {#define CONDITION(c) if (!(c)) break;#define ON#define SUCCESS b = true;#define END } while(false);#define FAIL if (!b) do { do {Of course I didn't use these defines to accomplish the task.
Edit: Missed the ON FAIL bit. Okay okay, so mine now doesn't work if you use it twice in the same function. That's what you get for using END to mean two different things.
Quote:Edit: Missed the ON FAIL bit. Okay okay, so mine now doesn't work if you use it twice in the same function. That's what you get for using END to mean two different things.
Thats simple to fix :P
#define CHECKLIST if (bool b=false); else do {#define CONDITION(c) if (!(c)) break;#define ON#define SUCCESS b = true;#define END } while(false);#define FAIL if (!b) do { do {Edit: A quick F# version
let CONDITION c = clet ON = ()let SUCCESS = ()let END = ()let FAIL = ()let CHECKLIST conditions () () on_success () () () on_fail () () = if List.forall (fun c -> c) conditions then on_success () else on_fail ()CHECKLIST [ CONDITION(boolean logic) ; CONDITION(boolean logic) ; CONDITION(boolean logic) ; CONDITION(boolean logic) ; CONDITION(boolean logic) ; CONDITION(boolean logic) ] ON SUCCESS (fun () -> (* logic *)) END ON FAIL (fun () -> (* logic *)) ENDEND[Edited by - Julian90 on August 3, 2007 6:53:00 AM]
As you might have gathered by now, taking an if-statement and renaming it doesn't actually turn it into anything new. [wink]
I would make a Common Lisp implementation of your syntax, but it would be significantly more complicated than just doing this:
(if (and condition1 condition2 condition3 condition4 condition5 condition6) (progn "On success" code goes here) (progn "On fail" code goes here))This topic is closed to new replies.
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