Assigning value to a lazy parameter in a function call

[Chris Cain]

On Friday, 11 May 2012 at 20:45:53 UTC, Vidar Wahlberg wrote:
> I often call functions where one of the parameters may be an 
> integer which i post/pre increment/decrement. However, that can 
> be quite risky if the parameter is defined as "lazy" as shown 
> above.
> The value of "a" above after calling "log" depends on whether 
> you've compiled with "-debug" or not, this may not be very 
> obvious and may take some by surprise.
>
> Perhaps the compiler should print out a warning when you're 
> assigning a value to a lazy parameter in a function call?

The entire point of a lazy parameter is to not be
calculated/processed until it's actually necessary. This is
normal behavior for lazy. Most actual use cases for lazy would be 
made impractical if the compiler bombarded the programmer with 
warnings.