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FP::Abstract::Pure - functional purity protocol


    use FP::List;
    use Safe::Isa;
    my $v = list(1); # or any other data structure that implements
                    # FP::Abstract::Pure
    is $v->$_isa("FP::Abstract::Pure"), 1;

    # but usually:
    use FP::Predicates;
    is_pure($v) # true if $v does (officially) not support mutation


Base class for all data structures that don't allow mutation (by ordinary programs), i.e. are persistent.

More precisely, those objects that don't have methods that when called make other methods non-functions.


This is alpha software! Read the status section in the package README or on the website.