On 2009-04-08 10:46:19 -0400, bearophile <[email protected]> said:
I like contract programming, it helps me avoid bugs. This is an example from the docs:long squareRoot(long x) in { assert(x >= 0); } out (result) { assert((result * result) <= x && (result+1) * (result+1) >= x); } body { return cast(long)std.math.sqrt(cast(real)x); } But isn't a syntax like the following better?To me it looks more logic, because in{} and out(){} are part of the function, and there's no need of a special syntax for the body (and the 'body' keyword):long squareRoot(long x) { in { assert(x >= 0); } out (result) { assert((result * result) <= x && (result+1) * (result+1) >= x); } return cast(long)std.math.sqrt(cast(real)x); }
I believe the syntax should make the contracts part of the function signature, not part of the function body, because contracts are about expressing the function's interface. So I disagree with your proposed syntax which puts the contracts as part of the body.
I do agree however that reserving 'body' as a keyword is from time to time hindering. I'd certainly welcome a change if it allows removing 'body' as a keyword. But not this one, because it puts the contract at the wrong place.
-- Michel Fortin [email protected] http://michelf.com/
