11 Mar
2016
11 Mar
'16
1:26 p.m.
On Fri, Mar 11, 2016 at 04:56:57PM +0100, Han Joosten wrote:
In a rather large program I made some changes, and now I get the runtime error:
ampersand.exe: Prelude.head: empty list
Of course I know that head is partial, and should be used with care. It is used many times (we have 100+ modules in the program). Is there an elegant way to get some information about where the specific call to head is being made?
Thanks!
I scanned previous replies and didn't see it mentioned, maybe you can abuse C preprocessor to shadow `head` and insert a __LINE__ on pattern matching []?