Shareable

$ rakupp install Shareable

use Shareable;

class Note is Shareable { has Str $.title; has Int $.n }

my $f = $*TMPDIR.add("shareable-{$*PID}.store");
LEAVE $f.unlink;

my $a = Note.new(title => 'hello', n => 3);
$a.to-file($f.Str);
say 'file contents : ', $f.slurp.trim;
say '';
my $b = $a.from-file($f.Str);
say 'round-tripped : ', $b.raku;
say '  same class  : ', $b.^name;
say '  equal       : ', $b.title eq $a.title && $b.n == $a.n;
say '  identical   : ', $b === $a;
say '';
say 'from-file returns a NEW object and leaves self untouched — it is not';
say 'an in-place load.';

use Shareable;

class Note is Shareable { has Str $.title }

say 'the module keeps ONE module-level store path, shared by every';
say 'instance and subclass, defaulting to $HOME/.Shareable-store-file.';
say '';
say '  .show-store  reads it';
say '  .save        writes self to it';
say '  .store       is the same method under another name';
say '  .from-store  reads it back';
say '';
say 'and .new(:store-file(...)) does NOTHING. The `multi new(:$store-file)`';
say 'in the class body has no `method` keyword, so it is a lexical SUB,';
say 'not a constructor candidate — .new falls through to Mu.new and the';
say 'named argument is dropped:';
say '  ', Note.new(store-file => '/tmp/mine').show-store.IO.basename;

use Shareable;

class Note is Shareable { has Str $.title }

my $dir = $*TMPDIR.add("shareable2-{$*PID}");
LEAVE { $dir.add('a.store').unlink; $dir.add('b.store').unlink; $dir.rmdir }
$dir.mkdir;
my $a = $dir.add('a.store');
my $b = $dir.add('b.store');

my $n = Note.new(title => 'kept');
$n.to-file($a.Str);
say 'file A written : ', $a.e;
$n.set-store-file($b.Str);
say 'after set-store-file(B):';
say '  store is now : ', $n.show-store.IO.basename;
say '  file A       : ', $a.e ?? 'still there' !! 'GONE';
say '';
say 'the source is  method set-store-file($path) { unlink $storefile;';
say '$storefile = $path }. Nothing in the name suggests a deletion.';
say '';
say 'and the FIRST call in a fresh program unlinks whatever is at';
say '$HOME/.Shareable-store-file, because that is the default. "Point this';
say 'object at my own file" is spelled "delete the shared default store,';
say 'then point at my own file".';

use Shareable;

class Note is Shareable { has Str $.title }

my $f = $*TMPDIR.add("shareable3-{$*PID}.store");
LEAVE $f.unlink;
$f.spurt('do { say "  >>> code in the store file just ran <<<"; 42 }');

say 'loading a store file that contains an expression:';
my $r = Note.from-file($f.Str);
say '  result = ', $r.raku;
say '';
say 'Storable::Lite deserialises with EVAL under MONKEY-SEE-NO-EVAL.';
say 'Never point from-file or from-store at a file you did not write.';
say '';
say 'a missing file returns Bool::False after a warning — not Nil, not a';
say 'Failure — so `my $obj = $s.from-store;` silently yields False and';
say 'blows up somewhere else later:';
say '  from-file(missing) : ', Note.from-file('/no/such/store').raku;

use Shareable;

say 'the other divergence is scoping: `use Shareable` re-exports its';
say 'dependency`s exports under Raku++ and not under Rakudo.';
say '';
say '  after `use Shareable` alone:';
say '    FileStore, to-file and from-file as SUBS are visible on Raku++';
say '    and "Undeclared name" on Rakudo';
say '';
say 'so code written against Raku++ that calls to-file($path, $obj) as a';
say 'sub does not compile on Rakudo. Use the METHODS the class gives you,';
say 'which are the same on both:';
class Note is Shareable { has Str $.title }
my $f = $*TMPDIR.add("shareable4-{$*PID}.store");
LEAVE $f.unlink;
my $n = Note.new(title => 'portable');
$n.to-file($f.Str);
say '  .to-file / .from-file : ', Note.from-file($f.Str).title;