--- /dev/null
+-------------
+Version 5.000
+-------------
+
+New things
+----------
+ The -w switch is much more informative.
+
+ References. See t/op/ref.t for examples. All entities in Perl 5 are
+ reference counted so that it knows when each item should be destroyed.
+
+ Objects. See t/op/ref.t for examples.
+
+ => is now a synonym for comma. This is useful as documentation for
+ arguments that come in pairs, such as initializers for associative arrays,
+ or named arguments to a subroutine.
+
+ All functions have been turned into list operators or unary operators,
+ meaning the parens are optional. Even subroutines may be called as
+ list operators if they've already been declared.
+
+ More embeddible. See main.c and embed_h.sh. Multiple interpreters
+ in the same process are supported (though not with interleaved
+ execution yet).
+
+ The interpreter is now flattened out. Compare Perl 4's eval.c with
+ the perl 5's pp.c. Compare Perl 4's 900 line interpreter loop in cmd.c
+ with Perl 5's 1 line interpreter loop in run.c. Eventually we'll make
+ everything non-blocking so we can interface nicely with a scheduler.
+
+ eval is now treated more like a subroutine call. Among other things,
+ this means you can return from it.
+
+ Format value lists may be spread over multiple lines by enclosing in
+ a do {} block.
+
+ You may now define BEGIN and END subroutines for each package. The BEGIN
+ subroutine executes the moment it's parsed. The END subroutine executes
+ just before exiting.
+
+ Flags on the #! line are interpreted even if the script wasn't
+ executed directly. (And even if the script was located by "perl -x"!)
+
+ The ?: operator is now legal as an lvalue.
+
+ List context now propagates to the right side of && and ||, as well
+ as the 2nd and 3rd arguments to ?:.
+
+ The "defined" function can now take a general expression.
+
+ Lexical scoping available via "my". eval can see the current lexical
+ variables.
+
+ The preferred package delimiter is now :: rather than '.
+
+ tie/untie are now preferred to dbmopen/dbmclose. Multiple DBM
+ implementations are allowed in the same executable, so you can
+ write scripts to interchange data among different formats.
+
+ New "and" and "or" operators work just like && and || but with
+ a precedence lower than comma, so they work better with list operators.
+
+ New functions include: abs(), chr(), uc(), ucfirst(), lc(), lcfirst(),
+ chomp(), glob()
+
+ require with a number checks to see that the version of Perl that is
+ currently running is at least that number.
+
+ Dynamic loading of external modules is now supported.
+
+ There is a new quote form qw//, which is equivalent to split(' ', q//).
+
+ Assignment of a reference to a glob value now just replaces the
+ single element of the glob corresponding to the reference type:
+ *foo = \$bar, *foo = \&bletch;
+
+ Filehandle methods are now supported:
+ output_autoflush STDOUT 1;
+
+ There is now an "English" module that provides human readable translations
+ for cryptic variable names.
+
+ Autoload stubs can now call the replacement subroutine with goto &realsub.
+
+ Subroutines can be defined lazily in any package by declaring an AUTOLOAD
+ routine, which will be called if a non-existent subroutine is called in
+ that package.
+
+ Several previously added features have been subsumed under the new
+ keywords "use" and "no". Saying "use Module LIST" is short for
+ BEGIN { require Module; import Module LIST; }
+ The "no" keyword is identical except that it calls "unimport" instead.
+ The earlier pragma mechanism now uses this mechanism, and two new
+ modules have been added to the library to implement "use integer"
+ and variations of "use strict vars, refs, subs".
+
+ Variables may now be interpolated literally into a pattern by prefixing
+ them with \Q, which works just like \U, but backwhacks non-alphanumerics
+ instead. There is also a corresponding quotemeta function.
+
+ Any quantifier in a regular expression may now be followed by a ? to
+ indicate that the pattern is supposed to match as little as possible.
+
+ Pattern matches may now be followed by an m or s modifier to explicitly
+ request multiline or singleline semantics. An s modifier makes . match
+ newline.
+
+ Patterns may now contain \A to match only at the beginning of the string,
+ and \Z to match only at the end. These differ from ^ and $ in that
+ they ignore multiline semantics. In addition, \G matches where the
+ last interation of m//g or s///g left off.
+
+ Non-backreference-producing parens of various sorts may now be
+ indicated by placing a ? directly after the opening parenthesis,
+ followed by a character that indicates the purpose of the parens.
+ An :, for instance, indicates simple grouping. (?:a|b|c) will
+ match any of a, b or c without producing a backreference. It does
+ "eat" the input. There are also assertions which do not eat the
+ input but do lookahead for you. (?=stuff) indicates that the next
+ thing must be "stuff". (?!nonsense) indicates that the next thing
+ must not be "nonsense".
+
+ The negation operator now treats non-numeric strings specially.
+ A -"text" is turned into "-text", so that -bareword is the same
+ as "-bareword". If the string already begins with a + or -, it
+ is flipped to the other sign.
+
+Incompatibilities
+-----------------
+ @ now always interpolates an array in double-quotish strings. Some programs
+ may now need to use backslash to protect any @ that shouldn't interpolate.
+
+ Ordinary variables starting with underscore are no longer forced into
+ package main.
+
+ s'$lhs'$rhs' now does no interpolation on either side. It used to
+ interplolate $lhs but not $rhs.
+
+ The second and third arguments of splice are now evaluated in scalar
+ context (like the book says) rather than list context.
+
+ Saying "shift @foo + 20" is now a semantic error because of precedence.
+
+ "open FOO || die" is now incorrect. You need parens around the filehandle.
+
+ The elements of argument lists for formats are now evaluated in list
+ context. This means you can interpolate list values now.
+
+ You can't do a goto into a block that is optimized away. Darn.
+
+ It is no longer syntactically legal to use whitespace as the name
+ of a variable, or as a delimiter for any kind of quote construct.
+
+ Some error messages will be different.
+
+ The caller function now returns a false value in a scalar context if there
+ is no caller. This lets library files determine if they're being required.
+
+ m//g now attaches its state to the searched string rather than the
+ regular expression.
+
+ "reverse" is no longer allowed as the name of a sort subroutine.
+
+ taintperl is no longer a separate executable. There is now a -T
+ switch to turn on tainting when it isn't turned on automatically.
+
+ Symbols starting with _ are no longer forced into package main, except
+ for $_ itself (and @_, etc.).
+
+ Double-quoted strings may no longer end with an unescaped $ or @.
+
+ Negative array subscripts now count from the end of the array.
+
+ The comma operator in a scalar context is now guaranteed to give a
+ scalar context to its arguments.
+
+ The ** operator now binds more tightly than unary minus.
+
+ Setting $#array lower now discards array elements so that destructors
+ work reasonably.
+
+ delete is not guaranteed to return the old value for tied arrays,
+ since this capability may be onerous for some modules to implement.
+
+ Attempts to set $1 through $9 now result in a run-time error.
projects / p5sagit/p5-mst-13.2.git / commitdiff