NAME

       Parse::Keyword - DEPRECATED: write syntax extensions in perl

VERSION

       version 0.08

SYNOPSIS

         use Parse::Keyword { try => \&try_parser };
         use Exporter 'import';
         our @EXPORT = 'try';

         sub try {
             my ($try, $catch) = @_;
             &Try::Tiny::try($try, ($catch ? (&Try::Tiny::catch($catch)) : ()));
         }

         sub try_parser {
             lex_read_space;
             die "syntax error" unless lex_peek eq '{';
             my $try = parse_block;
             lex_read_space;

             my $catch;
             if (lex_peek(6) =~ /^catch\b/) {
                 lex_read(5);
                 lex_read_space;
                 die "syntax error" unless lex_peek eq '{';
                 $catch = parse_block;
             }

             return (sub { ($try, $catch) }, 1);
         }

DESCRIPTION

   DO NOT USE!
       This module has fundamental errors in the way it handles closures, which are not fixable.
       Runtime keywords will never be able to work properly with the current design of this
       module. There are certain cases where this module is still safe to use (keywords that only
       have effect at compile time, or keywords that never call any of the "parse_*" functions),
       but that is limiting enough to make this module mostly worthless, and I likely won't be
       continuing to maintain it. Be warned!

       NOTE: The API of this module is still in flux. I may make backwards-incompatible changes
       as I figure out how it should look.

       This module allows you to write keyword-based syntax extensions without requiring you to
       write any C code yourself. It is similar to Devel::Declare, except that it uses the Perl
       parser API introduced in Perl 5.14 in order to allow you to parse parts of things using
       perl's own parser, rather than having to fake it with balanced brace matching or other
       fragile things.

       To use this module, you should pass a hashref to the "use" statement. The keys of this
       hashref are subroutines in the current package which should have special parsing behavior
       attached to them, and the values are coderefs which should be used to implement the custom
       parsing behavior.

       The parsing coderefs will be called when perl encounters a call to the keyword that you
       attached custom parsing to. The current parser state will be directly after parsing the
       keyword. The parser function will receive the name of the keyword as a parameter, and
       should return a coderef which, when called at runtime, will produce the arguments to the
       function. In addition, if your keyword should be parsed as a statement (for instance, if
       you don't want to require a trailing semicolon), you can return a second, true value.

       In order to actually handle the parsing itself, this module also exports various parsing
       functions, which you can call. See below for details.

FUNCTIONS

   lex_peek($n)
       Returns a string consisting of the next $n characters in the input (or next one character,
       if $n isn't given). This string may be shorter than $n characters if there are fewer than
       $n characters remaining to read. The current position in the buffer to be parsed is not
       moved. See "PL_parser->linestr" in perlapi and "lex_next_chunk" in perlapi for more
       information.

       NOTE: This function currently only returns text that is on the current line, unless the
       current line has been fully read (via "lex_read"). This is due to a bug in perl itself,
       and this restriction will hopefully be lifted in a future version of this module, so don't
       depend on it. See the "BUGS" section for more information.

   lex_read($n)
       Moves the current position in the parsing buffer forward by $n characters (or one
       character, if $n isn't given). See "lex_read_to" in perlapi for more details.

   lex_read_space
       Moves the current position in the parsing buffer forward past any whitespace or comments.
       See "lex_read_space" in perlapi for more details.

   lex_stuff($str)
       Inserts $str into the current parsing buffer at the current location, so that future calls
       to "lex_peek" and such will see it. Note that this does not move the current position in
       the parsing buffer, so multiple calls to "lex_stuff" at the same location will end up
       inserted into the buffer in reverse order. See "lex_stuff_sv" in perlapi for more
       information.

   parse_block, parse_stmtseq, parse_fullstmt, parse_barestmt, parse_fullexpr, parse_listexpr,
       parse_termexpr, parse_arithexpr
       These functions parse the specified amount of Perl code, and return a coderef which will
       evaluate that code when executed. They each take an optional boolean parameter that should
       be true if you are creating a subroutine which will be going in the symbol table, or in
       other more obscure situations involving closures (the CVf_ANON flag will be set on the
       created coderef if this is not passed - see "t/unavailable.t" in this distribution). See
       "parse_block" in perlapi, "parse_stmtseq" in perlapi, "parse_fullstmt" in perlapi,
       "parse_barestmt" in perlapi, "parse_fullexpr" in perlapi, parse_listexpr, parse_termexpr,
       and "parse_arithexpr" in perlapi for more details.

   compiling_package
       Returns the name of the package that the keyword which is currently being parsed was
       called in. This should be used instead of "caller" if you want to do something like
       install a subroutine in the calling package.

BUGS

       Peeking into the next line is currently (as of 5.19.2) broken in perl if the current line
       hasn't been fully consumed. This module works around this by just not doing that. This
       shouldn't be an issue for the most part, since it will only come up if you need to
       conditionally parse something based on a token that can span multiple lines. Just keep in
       mind that if you're reading in a large chunk of text, you'll need to alternate between
       calling "lex_peek" and "lex_read", or else you'll only be able to see text on the current
       line.

       This module also inherits the limitation from Devel::CallParser that custom parsing is
       only triggered if the keyword is called by its unqualified name ("try", not "Try::try",
       for instance).

       This module doesn't yet work with lexical subs, such as via Exporter::Lexical. This will
       hopefully be fixed in the future, but will likely require modifications to perl.

       Please report any bugs to GitHub Issues at <https://github.com/doy/parse-keyword/issues>.

SEE ALSO

       Devel::CallParser

       Keyword::API

       Devel::Declare

SUPPORT

       You can find this documentation for this module with the perldoc command.

           perldoc Parse::Keyword

       You can also look for information at:

       •   MetaCPAN

           <https://metacpan.org/release/Parse-Keyword>

       •   RT: CPAN's request tracker

           <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Parse-Keyword>

       •   Github

           <https://github.com/doy/parse-keyword>

       •   CPAN Ratings

           <http://cpanratings.perl.org/d/Parse-Keyword>

AUTHOR

       Jesse Luehrs <doy@tozt.net>

COPYRIGHT AND LICENSE

       This software is Copyright (c) 2013 by Jesse Luehrs.

       This is free software, licensed under:

         The MIT (X11) License