Common things that are known to have problems or not work in Rakudo

(As of 2009-01-10.)
Where appropriate, provide a reference to the corresponding RT ticket. Note that we aren't trying to make a list of all known bugs -- that's what RT is for. This should just be for the common issues that people will want to be aware of or work around when playing with Rakudo.

• reading array/hash elements causes them to autovivify (RT #61882)
• incorrect parsing of blocks followed by 'if', 'unless', 'while', 'until', 'given', etc. (RT #57876)
• accessing outer lexicals from eval
• lazy lists
• lazy ranges
• prefix and postfix hyperoperators
• //= (RT #61880)
• operator overloading, defining new operators
• nested package/grammar/class declarations
• autothreading of methods over Junctions
• slices/indexing of Ranges (RT #61848)
• filling positional parameters by named argument (RT #54808)
• assigning values to %*ENV (RT #57400)
• methods on Match cannot be used as rule names (RT #57864)
• some things that should be readonly aren't
• autovivification of undefs to arrays/hashes
• my $x; ++$x; (RT #61924)
• my Int @a; (RT #61926)
• Perl 6 closures in regexes (although it is possible to execute some PIR, on the form {{ PIR HERE }})
• code assertions in regexes -- i.e., <?{...}> and <!{...}> (but PIR forms are available, as <? {{ PIR HERE }}>)
• interpolations of arrays, hashes, and method calls in strings (although the {...} code form works)

Things that do (mostly?) work in Rakudo

See also the twitter feed at http://twitter.com/rakudoperl.

• scalar, array, hash variables
• classes, methods, roles
• for, loop, repeat, while
• if, elsif, else, unless
• junctions
• selected infix hyperoperators, reduction operators, cross (X) and zip (Z) operators
• slicing syntax
• chained comparison operators ( if 1 < $a < 100 { ... } )
• whatever star in slices
• closures
• currying (i.e., .assuming)
• simple next/last/redo
• given/when
• take/gather
• pointy blocks ( -> $foo { ... } )
• open (:w or :r) and slurpy files (and that is all, IO not implemented yet)
• eval some code