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.