Perl New Features
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Perl New Features

The evolution of Perl from v5.10 to now.

About the Book

I've collected to "new features" posts from The Effective Perler, updated them, and put them into a single book. Read about the new features, deprecations, and other changes to Perl since v5.8 to v5.32.

About the Author

brian d foy
brian d foy

brian d foy is one of the most profilic authors in the Perl programming community. He's the author of Mastering Perl and Learning Perl 6, and the co-author of Learning Perl, Intermediate Perl, Programming Perl, Effective Perl Programming, and others. He helps people and companies use Perl through education, training, and consulting.

Table of Contents

  • Preface
  • Introduction
  • Perl v5.10
    • Turn on new features implicitly
    • Enable features on the command line
    • Newlines for free
    • Lexically-persistent variables
    • Defined-or
    • Method resolution orders
    • Stacked file test operators
    • Architecture-dependent pack formats
    • Branch reset numbering
    • Generic line ending
    • Grammars in regex
    • Named captures
    • Relative back references
    • Ignore part of a substitution's match
  • Perl v5.12
    • Specify the package version inline
    • The each operator works on arrays
    • The length of undef is undef
    • Local hash key deletion
    • Not-a-newline character class
    • Get strict for free
    • The yada yada operator
  • Perl v5.14
    • Enforce ASCII semantics when you want only ASCII
    • Default regular expression modifiers
    • Regex stringification changes
    • Specify any character by its octal ordinal value
    • Pure ASCII semantics in regexes
    • non-destructive substitutions
    • Non-destructive transliteration
    • Package blocks
    • Get the pseudorandom seed
  • Perl v5.16
    • Proper case folding
    • Unicode loose name matching
    • Refer to the current subroutine
    • Unicode property inversion map
  • Perl v5.18
    • Computed loop labels
    • The experimental pragma
    • Experimental features warn
    • Character class set operations
    • The vertical tab is part of \s
  • Perl v5.20
    • -F implies -a and -n
    • Key/value slices
    • Fixes to taint problems with locale
    • The prototype attribute
    • Subroutine signatures
  • Perl v5.22
    • Reference aliasing
    • Safe command-line handling with the double diamond
    • Hexadecimal floating point literals
    • Turn all capture groups into cluster groups
    • Fancy unicode word boundaries
  • Perl v5.24
    • Automatic dereferencing is gone
    • Lexical topic is gone
    • Postfix dereferencing
    • Line break word boundary
  • Perl v5.26
    • An array for all capture buffers
    • Deprecation warnings include version
    • @INC Drops the Current Directory
    • keys in scalar context now returns the count
    • Indented heredocs
    • Escape the left brace in a regex
    • Mix assignment and reference aliasing
    • Named lexical subroutines
    • Don't use POSIX to create temporary files
    • Perl v5.26 now recognizes version control conflict markers
    • Comments in character classes
  • Perl v5.28
    • Strictly numeric bitwise operators
    • Delete key-value slices
    • Initialize aggregates in state
    • Safer in-place editing
    • Zero-width heredoc delimiters forbidden
  • Perl v5.30
    • Postfix false conditions forbidden in declarations
    • Fixed single-quoted pre-compiled patterns that use named characters
    • Variable-width lookbehinds
  • Perl v5.32
    • The class instance operator, isa
    • Alpha assertions for extended patterns
    • Match only the same Unicode script
    • Chained comparison operators

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