Changes for 6.2.13 (r14402) - October 17, 2006

Build System

• Perl 5 embedding is now enabled by default
  • For Windows users, Perl 5.8.x is required
  • Set the PUGS_EMBED environment variable to noperl5 to disable this

• Prompting for Parrot embedding is now disabled by default
  • Set the PUGS_EMBED environment variable to parrot to enable this

• Support for compiling using GHC 6.6
  • GHC 6.4.1+ is still supported, but 6.6 will be required in the next release

Feature Changes

Interactive Shell and Command-Line Flags

• New pugs -d flag to display a trace for debugging
• The :r command now resets the environment once, not twice
• The return value of blocks, such as gather {...}, is displayed correctly
• $_ is no longer clobbered with the result of each expression's evaluation

Perl 5 Interoperability

• Arrays and Hashes now round-trip from Pugs to Perl 5 land and back
• Importing functions from Perl 5: use perl5:CGI <header param>
• Passing unboxed values across runtimes no longer leaks memory
• When embedding Perl 5.8+, Unicode flag is now on for Pugs-to-Perl5 strings
• eval($str, :lang<perl5>) now accepts non-ASCII characters in $str

Lexical Syntax

• Capture literals: \($bar: 1, 2, 3, named => 4)
• Here-docs now work as specced; also warns against inconsistent indentation
• Interpolation of chained calls: "$foo.meth.meth.meth.meth()"
• List comprehension: for 0 < list(@x) < 10 {...}
• Named character escapes: "\c[LATIN CAPITAL LETTER Y]"
• New grammatical category term:, separated from the prefix: category
• New magical variables: $?COMPILER and $?VERSION
• Parse for LABEL: STMT, although it's currently treated the same as STMT
• Pod directives: =begin/=end and =for now terminate without =cut
• Pod variables: $=FOO and @=FOO give you access to the Pod section FOO
• Quote adverbs no longer take non-parens brackets: rx:P5{...} is valid again
• Shell-like quoting rules implemented for << $x "qq" 'q' >>
• Signature literals: :($foo is copy = 42, $, @)
• Support for UTF-8, UTF-16 and UTF-32 encoded source files
• Support for backquotes and qx/.../ for capturing external command output
• User-defined infix associativity: sub infix:<foo> is assoc('right') {...}
• "\123" and "\03" are now errors; write "\d123" and "\o03" instead
• $::x now means exactly the same a $x, instead of $*x
• %h<> now means %h{} -- the entire hash, not the empty string as key
• ($::('x')) with two adjacent closing parens now parses correctly
• 0_123_456 now parses as 0d123456, not an error
• 1<2> is now a fatal error: Odd number of elements in Hash
• q() and qw() with parentheses are parsed as functions, not quotes

Declarators and Operators

• Argument interpolation via prefix | and |<<
• Binding to qualified uninitialised symbols: &fully::qualify := sub {...}
• Contextual variables are now declared with my $x is context, not env $x
• Hyperised reduce operators: [>>+<<] and [\>>+<<]
• Implicit invocation assignment: .= uc is parsed as $_ = $_.uc
• Mid-block redeclaration no longer allowed: my $x; { $x = 1; my $x = 2 }
• Negated comparison operators: !eqv, !=:= etc; !~~ replaces !~
• New infix comparison operators: === and eqv
• New infix non-short-circuiting boolean AND operator: ?&
• Nullary reduction of builtin operators gives identity values: [*]() === 1
• Postfix operators can be called with a dot: .++, $x.++, $x.\ ++
• Prefix = now iterates on arrays as well: =@array
• Short-circuiting chained comparison: 1 > 2 > die('foo') no longer fails
• Smart matching against code objects: $obj ~~ { 1 > $_ > 5 }
• Smart matching against implicit invocation: $obj ~~ .meth, $obj ~~ .[0]
• Typed constraints on autovivification: my Hash $x; $x[0] = 1 now fails
• Typed declarations: my Dog $fido, my T ($x, $y)
• * is now always a term, never a prefix operator

Blocks and Statements

• Implicit invocation in when: when .true {...} , when .<key> {...}
• Listops in conditions no longer consume the block: for say {...}
• Loop topics are not forced into rw: for 1..3 { $_++ } now fails correctly
• New &break and &continue primitives for use within when blocks
• New &leave primitive for exiting from the innermost block
• New postfix given statement modifier: .say given foo()
• Support for FIRST, NEXT, LAST loop control blocks
• Support for START, PRE, POST, KEEP, UNDO, ENTER, LEAVE blocks
• Support for repeat blocks: repeat {...} while 1, repeat while 1 {...}
• Support for the &each list interleaver: for each(@a; @b) -> $x, $y {...}
• The for loop no longer double-flattens lists: for %h.pairs -> $p {...}
• Topicalisers for if, else, while, given blocks: if EXPR -> $x {...}
• Topicalisers for postfix for loop: -> $x {...} for 1,2,3
• &last and &redo now work in repeat {...} and loop {...} blocks
• &take no longer flattens array literals: take [1,2,3];
• &take now works in functions called from within a gather {...} block
• BEGIN(...), END(...), etc., are now parsed as calls, not syntax errors
• END {...} in .pm files are no longer ignored when executed directly
• INIT {...} now works correctly inside eval "..."
• do {...} is now a loop block that takes standard loop controls
• do {...} with statement modifiers is explicitly disallowed

Regexes and Grammars

• Anonymous tokens and rules anchor on both ends: 123 ~~ token{2} is false
• New s[...] = EXPR and s[...] = .meth syntax; s[...][...] is deprecated
• New tr/// syntax for transliteration; y/// will not be supported
• Pugs::Compiler::Rule (PCR) replaces Parrot/PGE as the default engine
• Support for :c/:continue, <prior>, and much more: see PCR's ChangeLog
• $(), @() and %() parse correctly as $$/, @$/ and %$/
• /.../ matches $_ under Int, Num and void context in addition to Bool
• m:g/(1)|(2)/ now returns only successfully matched subcaptures

Modules and Routines

• Allow space-separated adverbial named arguments: f( :x<foo> :$y :!z )
• Multi-dispatching now handles named, slurpy and optional arguments
• Multi-dispatching now handles parenthesized expressions as arguments
• Named arguments with no matching parameters is now an error
• New &c.call($capture) method to call without a caller frame (similar to Perl 5's goto &sub, but it returns)
• New &c.signature method to get a Signature object from a Code object
• Parse for the proto routine modifier: proto method foo ($x) {...}
• Precompiled .pm.yml files with mismatching AST version will no longer load
• Support for user-defined unary and optional-unary prefix macros
• The main package is now ::Main, not ::main
• &?CALLER_CONTINUATION is now fully reentrant
• &yield in coroutines works correctly within loop blocks
• sub ($x = 0 is copy) no longer allowed; say sub ($x is copy = 0) instead
• sub f ($x is lazy) {...} no longer evaluates $x more than once
• sub f (@x?) {...}; f() now sets @x to [], not [undef]

Classes and Objects

• Attribute-like method call syntax: @.method(1), $.method: 2, 3, 4
• Class attributes: class C { my $.x is rw }
• Class name literals are now term macros, not prefix functions
• Compile-time self-mixin no longer allowed: role A does A
• Default initialiser expression for attributes: class C { has $.x = 123 }
• Dot attributes are now method calls: @.x is the same as @(self.x)
• Dynamic method calls: $obj.$meth
• Hyperised method calls: $obj.>>meth
• Quantified method calls: $obj.*meth, $obj.+meth and $obj.?meth
• Reopening classes: class C is also {...}
• Role mixins: role R {...} class C does R {...}
• $?SELF is gone; write self instead
• BUILDALL/DESTROYALL trigger once per class even with diamond inheritance
• does R and is C statements in class body now evaluate in compile time

Built-in Primitives

• New &HOW, &WHAT and &WHICH functions replace &meta, &ref and &id
• New &VAR macro to force lvalue evaluation of an expression
• New &comb function, a dual to &split but matches the wanted parts
• New &crypt function to create one-way digest strings
• New &fork function to create a new process
• New &printf function for formatted printing
• New &quotemeta function for escaping strings
• Support for %b in formatted printing
• The &system function no longer dies when the command does not exist
• The .as method is renamed to .fmt for formatted printing
• The .perl method now returns Unicode strings

Bundled Modules

New modules

• ext/Automata-Cellular/ - Build and render cellular automata in a terminal
• ext/Math-Basic/ - Basic mathematical functions and constants
• ext/Math-Random-Kiss/ - Pseudo-random number generator
• ext/re/ - Pragma to choose among grammar engine backends

ext/CGI/

• A new as_yaml method to dump CGI parameters as YAML
• Allow initializing the CGI object with a hash of parameters
• New Dump function adapted from Perl 5's CGI.pm
• New basic tests for escapeHTML and unescapeHTML, which were broken
• New tests for PATH_INFO
• Only send the Content-Type: header if we actually have a content-type
• Only send the Status: header if it's a redirect, or if it's explicitly added
• Refactored into an OO-only module. N.B.: this breaks backwards compatibility!
• Some work on charset handling, though a charset method is still missing
• The content_type method is renamed to type for compatibility
• The cookies attribute is renamed to cookie for compatibility

ext/HTTP-Server-Simple/

• The old non-standard ./method syntax has been replaced with self.method

ext/Rosetta/

• Significant updates to the lib/Rosetta/SeeAlso.pod documentation

ext/Set-Relation/

• Renamed from ext/Relation/
• Beginning of separate Set::Tuple and Set::Relation classes

ext/Test/

• Converted Test.pm documentation from Kwid to Pod syntax
• The eval_ok and eval_is functions are gone; use is eval instead, which runs its string in the current lexical scope rather than in Test's (which is usually what you want)

Test Suite

util/prove6

• Can now run only a portion of the test suite, or even a single file
• Original shell script rewritten in Perl 5 for improved portability
• Support for multiple Pugs backends and multiple Perl 6 implementations

util/smartlinks.pl

• A new visualiser of smartlinks used in the test suite
• Generates much nicer cross-referenced HTML pages
• See annotated specs in action on http://spec.pugscode.org/
• Smartlinks replace the old util/catalog_tests.pl

util/smokeserv/

• See the SYN links on http://smoke.pugscode.org/ for this in action
• Smoke client now uploads raw .yml results as well as .html
• The smokeserver now annotates the spec with test results using smartlinks

t/

• All tests now begin with use v6-alpha; instead of use v6;
• Many, many more smartlinks have been added into the spec
• Programs and modules in examples/ are tested for syntactic correctness
• Tests in t_disabled/ are merged back into the main test suite
• t/02-test-pm/ created to ensure that Test.pm works as advertised
• t/blocks/ renamed from t/subroutines/
• t/closure_traits/ created to test closure traits (FIRST, LAST, etc.)
• #!/usr/bin/pugs is gone from all test files
• eval_ok and eval_is are now ok eval and is eval, so that eval'd strings will be run in the current lexical scope

Examples and Utilities

examples/

   
• All Perl 5 programs have been renamed from *.p5 to *-p5.pl
   
• All Perl 6 programs have been renamed from *.p6 to *.pl
• All references to them, except in talks, have been likewise updated

examples/games/dispatch_quiz.pl

• A game to test your knowledge about Perl 6's multi-dispatch system

misc/runpugs/

• A web teminal for running an interactive Pugs shell on the web
• WebTerminal: a library for building web terminals for interactive shells
• See http://run.pugscode.org/ for a live demo

Documentation

docs/Perl6/Perl5/Differences.pod

• Significantly updated and linked from http://spec.pugscode.org/

docs/Perl6/Spec/

• A new S16 draft for IO/IPC/signals as docs/Perl6/Spec/IO.pod
• A new S26 draft for documentation as docs/Perl6/Spec/Documentation.pod
• Revamped S29 draft in docs/Perl6/Spec/Functions.pod

docs/Pugs/Doc/

• New directory for Pugs-specific documentation
• docs/Pugs/Doc/Hack/Style.pod - Haskell style guide for Pugs hackers

docs/talks/extraction.xul

• Slides from Nathan Gray's Practical Extraction with Perl 6 talk

Perl 6 on Perl 5

perl5/Pugs-Compiler-Perl6/

• The v6.pm implementation of Perl 6 now handles ./pugs -CPerl5 commands
• See its own ChangeLog for more information

v6/

• A new subproject to write a Perl 6 compiler in Perl 6
• Bootstrapped from the v6.pm compiler on the perl5 runtime
• See its own ChangeLog for more information

Experimental projects

misc/pX/Common/P5_to_P6_Translation/

• Converts Perl 5.9.4+'s YAML syntax tree into Perl 6
• Handles regexes, arrays, hashes and many builtin functions
• See its own documentation for more information

misc/pX/Common/convert_regexp_to_six.pl

• Converts Perl 5 regex into Perl 6
• See its own documentation for more information

misc/pX/Common/redsix/

• An Perl 6 implementation on Ruby 1.9+
• See its own documentation for more information