• Iustin Pop's avatar
    Automatically enable version-dependent GHC flags · 39f0eea5
    Iustin Pop authored
    
    
    Some GHC flags are very useful, but only appear in more recent GHC
    versions. To support the use of such flags while still supporting
    older compilers, let's add conditional checks and enabling based on
    the results.
    
    Currently only `-fwarn-incomplete-uni-patterns` is enabled, which
    detects refutable patterns in lambda expressions and pattern bindings
    (e.g. "let (Just x) = y"); such constructs are bad as they can lead to
    runtime exceptions.
    
    Additionally, fix an existing such bad construct in a test case; we
    workaround it by using error, since that should never fail.
    Signed-off-by: default avatarIustin Pop <iustin@google.com>
    Reviewed-by: default avatarGuido Trotter <ultrotter@google.com>
    39f0eea5
Cluster.hs 18 KB