id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc
23,Missing support for generalised list comprehensions,nibro,nibro,"This extension allows SQL-like clauses in list comprehensions:
{{{
employees = [ (""Simon"", ""MS"", 80)
, (""Erik"", ""MS"", 100)
, (""Phil"", ""Ed"", 40)
, (""Gordon"", ""Ed"", 45)
, (""Paul"", ""Yale"", 60)]

output = [ (the dept, sum salary)
| (name, dept, salary) <- employees
, then group by dept
, then sortWith by (sum salary)
, then take 5 ]
}}}
Should be trivial to implement parser-wise, like with parallel list comprehensions the main question is how to support these in the AST. Probably keep them separate from ordinary statements. Also I need to investigate if/how parallel and generalised list comprehensions go together. My guess is they simply don't.

[http://www.haskell.org/ghc/docs/latest/html/users_guide/syntax-extns.html#generalised-list-comprehensions]",bug report,closed,minor,Full code support,parser,,fixed,,