Overview - Chapter 0:Intr, 1:Hist, 2:Design, 3:Var, 4:Op, 5:IO, 6:{}, 7:Sub, 8:OOP, 9:Rx - Appendices: A:Index, B:Tables, C:Best of, D:Delta, E:Links

This summary lists things people should be aware of, that change from Perl 5 to 6.

Changes

• use strict and warnings are on by default

• consistent sigils: so @array[1] replaces $array[1] and %hash{'key'} replaces $hash{'key'} or @hash{'key', 'key2'}
• arrays, hashes, formats, directories and filehandles are internal objects with procedural Interfaces and can be saved in scalar variables.
• special variables have their own namespace ($VARNAME and $?VARNAME), also token (__LINE__) will now be found there
• Methods: . (dot) replaces -> (arrow) : object.method;
• concatenate strings: ~ (tilde) instead of . (dot): $string = 'Shinmen Musahashi: ' ~ 'Sho Rin No Sho';
• smartmatch (regex and more): ~~ instead of =~
• < ... > replaces qw( ... )(exists still): interpolating << ... >>
• ternary operator: ?? ... !! ... instead of ? ... : ...
• no more 'foreach'. 'for' now iterates only on arrays
• c-style loops: loop ( ; ; ) instead of for ( ; ; )
• after loop flow control: repeat { ... } while ... ; replaces do { ... } while (...);
• define classes with 'class' and modules with 'module'
• no more source filters, but macros
• no more references, bind variables on the symbol table

News

• new contexts: hashlist, lazy list, bool, int, num, string
• optional typing, traits (properties of variables), binding
• loop and say commands
• zip, err, yadda and pipe operators
• hyper / reduction operators
• chained comparison operators
• case construct with given and when
• junctions : if $a = 1|2|3
• currying
• smartmatch / rules (regex++, own sublanguage within the language like in Rebol)
• named parameters for subroutines, multimethods, coroutines
• more explicit OOP:
• autogenerated getters/setters
• roles (similar to Ruby's Mixins, or Java's Interfaces)
• delegation, design by contract (Eiffel)
• exceptions, continuations
• macros

Native Perl 6

• no parentheses required for control expressions after if, unless, while ... (but still allowed)
• $hash<key> instead of $hash{'key'}, or $hash<<key>> instead of $hash{"key"}

Overview - Chapter 0:Intr, 1:Hist, 2:Design, 3:Var, 4:Op, 5:IO, 6:{}, 7:Sub, 8:OOP, 9:Rx - Appendices: A:Index, B:Tables, C:Best of, D:Delta, E:Links