How to generate an array with random values, without using a loop?

Question

How can I generate an array in Perl with 100 random values, without using a loop?

I have to avoid all kind of loops, like \"for\", foreach\", while. This is my exerc

Answer 1

map is used here as a topicalizer over a single value, exempting it from loop status:

my @rand = map&$_($_),sub{@_<=100&&goto&{push@_,rand;$_[0]};shift;@_};

or with two subs:

my @rand = sub{&{$_[0]}}->(sub{@_<=100&&goto&{(@_=(rand,@_))[-1]};pop;@_});

both of these are Y-combinator style self-passed subs that build up the list via iteration but one is clearly faster than the other.

you can fix the inefficiency with s'g[^}]+'goto&{unshift@_,rand;$_[-1]' but then its getting a bit long.

or to sidestep the call stack:

my @rand = do{local*_=sub{(push@_,rand)<100?goto&_:@_};&_};

or with eval, no variable assignment, no external state, one anon sub:

my @rand = eval'sub{@_<100?eval((caller 1)[6]):@_}->(@_,rand)';

but most concise of all is:

my @rand = map&$_,sub{(100^push@_,rand)?goto&$_:@_};