diff options
Diffstat (limited to 'Changes')
| -rw-r--r-- | Changes | 64 |
1 files changed, 54 insertions, 10 deletions
@@ -47,8 +47,6 @@ New things Lexical scoping available via "my". eval can see the current lexical variables. - Saying "package;" requires explicit package name on global symbols. - The preferred package delimiter is now :: rather than '. tie/untie are now preferred to dbmopen/dbmclose. Multiple DBM @@ -58,10 +56,8 @@ New things 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() - - require with a bare word now does an immediate require at compile time. - So "require POSIX" is equivalent to "BEGIN { require 'POSIX.pm' }". + 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. @@ -86,15 +82,53 @@ New things routine, which will be called if a non-existent subroutine is called in that package. - There is now a pragma mechanism, using the keywords "aver" and "deny". - Current pragmas are "integer" and "strict". Unrecognized pragmas - are ignored. + 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. @@ -111,7 +145,7 @@ Incompatibilities 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. + of a variable, or as a delimiter for any kind of quote construct. Some error messages will be different. @@ -135,3 +169,13 @@ Incompatibilities 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. |