ghc-safe

Library of safe (exception free) functions

A library wrapping 'Prelude'/'Data.List' functions that can throw exceptions, such as 'head' and '!!'. Each unsafe function has up to four variants, e.g. with 'tail': * 'tail :: [a] -> [a]', raises an error on 'tail []'. * 'tailMay :: [a] -> /Maybe/ [a]', turns errors into 'Nothing'. * 'tailDef :: /[a]/ -> [a] -> [a]', takes a default to return on errors. * 'tailNote :: /String/ -> [a] -> [a]', takes an extra argument which supplements the error message. * 'tailSafe :: [a] -> [a]', returns some sensible default if possible, '[]' in the case of 'tail'. This package is divided into three modules: * "Safe" contains safe variants of 'Prelude' and 'Data.List' functions. * "Safe.Foldable" contains safe variants of 'Foldable' functions. * "Safe.Exact" creates crashing versions of functions like 'zip' (errors if the lists are not equal) and 'take' (errors if there are not enough elements), then wraps them to provide safe variants.