6.7.1. Pattern guards¶
-
PatternGuards
¶ Since: 6.8.1 Status: Disabled in Haskell98
, enabled inHaskell2010
and later.Haskell 2010 allows pattern match guards to contain pattern guards:
case animal of Fish { name=nm } | "bob" <- nm -> "it's Bob!" -- ^^^^^^^^^^^ a pattern guard
This extension controls whether pattern guard syntax is allowed, independent of language edition.