# Grammar.grammar is used to generate
# lib/Pugs/Grammar/Rule.pmc using util/compile_p6grammar.pl
# This file makes lib/Pugs/Grammar/Rule2.pm obsolete.
# Please regen Rule.pmc and rerun the whole test suite
# of Pugs::Compiler::Rule and v6.pm to ensure you didn't
# break things :)
#
# Usage:
#   util/compile_p6grammar.pl examples/Grammar.grammar > Grammar.pm
#   perl -MGrammar -e 'print Pugs::Grammar::Rule->rule("a b")->to, "\n"'
#

grammar Pugs::Grammar::Rule;

%{

use utf8;
no strict 'refs';
no warnings 'redefine';
no warnings 'once';

#use Pugs::Runtime::Match;

our %rule_terms;
our %variables;

%}

token pod_begin {
    |   \n =end \N*
    |   . \N* <.pod_begin>
}

token pod_other {
    |   \n =cut \N*
    |   . \N* <.pod_other>
}

token ws {
    [
    |    \# \N*
    |    \n [ = [
            |  begin <.ws> END \N* .*
            |  begin  <.pod_begin>
            |  kwid   <.pod_other>
            |  pod    <.pod_other>
            |  for    <.pod_other>
            |  head1  <.pod_other>
            ]?
            ]?
    |    \s
    ]+
}

# regex ident can start with a number
token ident {
    [ <.alnum> | _ | '::' ]+
}

token alnum {
    <[0-9a-zA-Z]>
}

token alpha {
    <[a-zA-Z]>
}

token digit {
    <[0-9]>
}

# after '\\'
token special_char {
        | ( c | C ) \[ ( [<alnum>|\s| ';' | '(' | ')' | '-' ]+) \]
          #  \c[LATIN LETTER A]
          { return { special_char => '\\' . $0 . $1, _pos => [$/->from - 1, $/->to] }; }

        | [ x | X ] <xdigit>+
          #  \x0021    \X0021
          { return { special_char => '\\' . $/, _pos => [$/->from - 1, $/->to] }; }
        | ( x | X ) \[ (<xdigit>+) \]
          #  \x[0021]  \X[0021]
          { return { special_char => '\\' . $0 . $1, _pos => [$/->from - 1, $/->to] }; }

        | [ o | O ] \d+
          #  \o0021    \O0021
          { return { special_char => '\\' . $/, _pos => [$/->from - 1, $/->to] }; }
        | ( o | O ) \[ (\d+) \]
          #  \o[0021]  \O[0021]
          { return { special_char => '\\' . $0 . $1, _pos => [$/->from - 1, $/->to] }; }

        | .
          #  \e  \E
          { return { special_char => '\\' . $/, _pos => [$/->from - 1, $/->to] }; }
}

token literal {
    [
    |  \\ <special_char>
    |  <-[ \' ]>
    ]*
}

token double_quoted {
    [
    |  \\ <special_char>
    |  <%Pugs::Grammar::Rule::variables>
    |  <-[ \" ]>
    ]*
}

token metasyntax {
    [
    |  \\ <special_char>
    |  \'  <.literal>     \'
    |  \"  <.double_quoted>   \"
    |  \{  <.string_code>        \}
    |  \<  <.metasyntax>  \>
    |  <-[ \> ]>
    ]+
}

token char_range {
    [
    |  \\ <special_char>
    |  <-[ \] ]>
    ]+
}

token char_class {
    |  <.alpha>+
    |  \[  <.char_range>  \]
}

token string_code {
    # bootstrap "code"
    [
    |  \\ <special_char>
    |  \'  <.literal>     \'
    |  \"  <.double_quoted>   \"
    |  \{  [ <.string_code> | '' ]  \}
    |  \(  [ <.string_code> | '' ]  \)
    |  \<  [ <.string_code> | '' ]  \>
    |  [ <.ws> | \> | \= | \- ] \>
    |  <.ws>
    |  <-[ \} \) \> ]>
    ]+
}

token parsed_code {
    # this subrule is overridden inside the perl6 compiler
    <.string_code>
    { return '{' . $/ . '}'; }
}

token named_capture_body {
    | \(  <rule>        \)  { return { capturing_group => $$<rule>,
                              _pos => [ $/->from, $/->to ], }; }
    | \[  <rule>        \]  { return $$<rule> }
    | \<  <parse_metasyntax>  { return $$<parse_metasyntax> }
    | \'  <.literal>    \'
        { return { metasyntax => {
                        metasyntax => "${$/}",
                        },
                   _pos => [ $/->from, $/->to ],
                };
        }
    | { die "invalid alias syntax"; }
}

token parse_metasyntax {
        $<modifier> := [ '!' | '?' | '.' | '' ]
    [
        '{'  <parsed_code>  '}>'
        { return { closure => {
            closure  => $$<parsed_code>,
            modifier => $$<modifier>,
        },
            _pos => [ $/->from - 1, $/->to ],
        } }
    |
        <char_class>
        ( <[+-]> <char_class> )+
        \>
        {
            if ( $$<modifier> eq '!' ) {
              return {
                negate => {
                  char_class => [
                    '+' . $<char_class>,
                    @{$/[0]},   # TODO - stringify
              ] } }
            }
            return {
              char_class => [
                '+' . $<char_class>,
                @{$/[0]},   # TODO - stringify
            ] }
        }
    |
        <ident>
        [
          <.ws> <rule> \>
          {
            if  ( $$<ident> eq 'before'
               || $$<ident> eq 'after'
                ) {
                return { $$<ident> => {
                    rule => $$<rule>, modifier => $$<modifier>,
                     }, _pos => [ $/->from - 1, $/->to ], }
            }
            return { metasyntax => {
                        metasyntax => $$<ident>,
                        rule       => $$<rule>,
                        modifier   => $$<modifier>,
                    },
                    _pos => [ $/->from - 1, $/->to ],
                }
          }
        |
          ':' <.ws>?
          $<str> := [
            [
            |  \\ <special_char>
            |  <%Pugs::Grammar::Rule::variables>
            |  <-[ \> ]>
            ]*
          ]
          \>
          {
            if  ( $$<ident> eq 'before'
               || $$<ident> eq 'after'
                ) {
                return { $$<ident> => {
                    rule     => { metasyntax => {
                                metasyntax => '\'' . $$<str> . '\'',
                            },
                        _pos => [ $<str>->from, $<str>->to ],                   },
                    modifier => $$<modifier>,
                    _pos => [ $/->from - 1, $/->to ],
                } }
            }
            return { metasyntax => {
                metasyntax => $$<ident>,
                string   => $$<str>,
                modifier => $$<modifier>,
            },
                _pos => [ $/->from - 1, $/->to ],
            }
          }
        |
          \(  <parsed_code>  \) \>
          { return { call => {
              method   => $$<ident>,
              params   => $$<parsed_code>,
              modifier => $$<modifier>,
          },
              _pos => [$/->from - 1, $/->to], } }
        ]
    |
        <metasyntax>  \>
        { return { metasyntax => {
              metasyntax => "$$<metasyntax>",
              modifier   => $$<modifier>,
        },
              _pos => [ $/->from - 1, $/->to ],
        } }
    ]
}

#################################
# set %variables
#################################

token var1 {
        <ident> \>
        { return { match_variable => '$' . $/{ident}, _pos => [$/->from - 2, $/->to], }; }
}

%{ $variables{'$<'} = sub { var1($_[1], $_[0], $_[2], $_[3]) }; %}

token var2 {
        <.digit>+
        { return { match_variable => '$' . $/, _pos => [$/->from - 1, $/->to], }; }
    |
        \^?
        [ <.alnum> | _ | \: \: ]+
        { return { variable => '$' . $/, _pos => [$/->from - 1, $/->to], }; }
}

%{ $variables{'$'} = sub { var2($_[1], $_[0], $_[2], $_[3]) }; %}

token var3 {
        <.digit>+
        { return { match_variable => '@' . $/, _pos => [$/->from - 1, $/->to], } }
    |
        \^?
        [ <.alnum> | _ | \: \: ]+
        { return { variable => '@' . $/, _pos => [$/->from - 1, $/->to], } }
}

%{ $variables{'@'} = sub { var3($_[1], $_[0], $_[2], $_[3]) }; %}

token var4 {
        <.digit>+
        { return { match_variable => '%' . $/, _pos => [$/->from - 1, $/->to] } }
    |
        \^?
        [ <.alnum> | _ | \: \: ]+
        { return { variable => '%' . $/, _pos => [$/->from - 1, $/->to] } }
}

%{ $variables{'%'} = sub { var4($_[1], $_[0], $_[2], $_[3]) }; %}

#################################
# set %rule_terms
#################################

token term1 {
        # placeholder
        { return { metasyntax => {
                        metasyntax => 'null',
        },
                        _pos => [ $/->from, $/->to ],
        } }
}

%{ $rule_terms{'{*}'} = sub { term1($_[1], $_[0], $_[2], $_[3]) }; %}

token term2 {
        <.literal>     \'
        { return {
                metasyntax => {
                    metasyntax => '\'' . ${$/},
                },
                    _pos => [ $/->from - 1, $/->to ],
            };
        }
}

%{ $rule_terms{'\''} = sub { term2($_[1], $_[0], $_[2], $_[3]) }; %}

token term3 {
        <rule> \)
        { return { capturing_group => $$<rule>,
                   _pos => [ $/->from - 1, $/->to ], }; }
}

%{ $rule_terms{'('} = sub { term3($_[1], $_[0], $_[2], $_[3]) }; %}

token term4 {
        <rule>  ')>'
        { return { capture_as_result => $$<rule>,
                   _pos => [ $/->from - 2, $/->to ], }; }
}

%{ $rule_terms{'<('} = sub { term4($_[1], $_[0], $_[2], $_[3]) }; %}

token term5 {
        <char_class>
        ( <[+-]> <char_class> )*
        \>
        { return {
            _pos => [ $/->from - 2, $/->to ],
            char_class => [
                '+' . $<char_class>,
                @{$/[0]},   # TODO - stringify
            ] }
        }
}

%{ $rule_terms{'<+'} = sub { term5($_[1], $_[0], $_[2], $_[3]) }; %}

token term6 {
        <char_class>
        ( <[+-]> <char_class> )*
        \>
        { return {
            _pos => [ $/->from - 2, $/->to ],
            char_class => [
                '-' . $<char_class>,
                @{$/[0]},   # TODO - stringify
            ] }
        }
}

%{ $rule_terms{'<-'} = sub { term6($_[1], $_[0], $_[2], $_[3]) }; %}

token term7 {
        <char_range>  \]
        ( <[+-]> <char_class> )*
        \>
        { return {
            _pos => [ $/->from - 2, $/->to ],
            char_class => [
                '+[' . $<char_range> . ']',
                @{$/[0]},   # TODO - stringify
            ] }
        }
}

%{ $rule_terms{'<['} = sub { term7($_[1], $_[0], $_[2], $_[3]) }; %}

token term8 {
        <parse_metasyntax>
        { return $$<parse_metasyntax> }
}

%{ $rule_terms{'<'} = sub { term8($_[1], $_[0], $_[2], $_[3]) }; %}

token term9 {
        <parsed_code>  \}
        { return { closure => {
            closure => $$<parsed_code>,
            modifier => 'plain',
        },
            _pos => [$/->from - 1, $/->to],
        } }
}

%{ $rule_terms{'{'} = sub { term9($_[1], $_[0], $_[2], $_[3]) }; %}

token term10 {
        <special_char>
        { return $$<special_char> }
}

%{ $rule_terms{'\\'} = sub { term10($_[1], $_[0], $_[2], $_[3]) }; %}

token term11 {
        { return { 'dot' => 1, _pos => [$/->from - 1, $/->to], } }
}

%{ $rule_terms{'.'} = sub { term11($_[1], $_[0], $_[2], $_[3]) }; %}

token term12 {
        <rule> \]
        { return $$<rule> }
}

%{ $rule_terms{'['} = sub { term12($_[1], $_[0], $_[2], $_[3]) }; %}

token term13 { { return { colon => ':::', _pos => [$/->from - 3, $/->to], } } }

%{ $rule_terms{':::'} = sub { term13($_[1], $_[0], $_[2], $_[3]) }; %}

token term14 { { return { colon => ':?', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{':?'} = sub { term14($_[1], $_[0], $_[2], $_[3]) }; %}

token term15 { { return { colon => ':+', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{':+'} = sub { term15($_[1], $_[0], $_[2], $_[3]) }; %}

token term16 { { return { colon => '::', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'::'} = sub { term16($_[1], $_[0], $_[2], $_[3]) }; %}

token term17 { { return { colon => ':', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{':'} = sub { term17($_[1], $_[0], $_[2], $_[3]) }; %}

token term18 { { return { colon => '$$', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'$$'} = sub { term18($_[1], $_[0], $_[2], $_[3]) }; %}

token term19 { { return { colon => '$', _pos => [$/->from - 1, $/->to],  } } }

%{ $rule_terms{'$'} = sub { term19($_[1], $_[0], $_[2], $_[3]) }; %}

token term20 { { return { colon => '^^', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'^^'} = sub { term20($_[1], $_[0], $_[2], $_[3]) }; %}

token term21 { { return { colon => '^', _pos => [$/->from - 1, $/->to], } } }

%{ $rule_terms{'^'} = sub { term21($_[1], $_[0], $_[2], $_[3]) }; %}

token term22 { { return { colon => '>>', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'>>'} = sub { term22($_[1], $_[0], $_[2], $_[3]) }; %}

# token term23 { { return { colon => '>>', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'»'} = sub { term22($_[1], $_[0], $_[2], $_[3]) }; %}

token term24 { { return { colon => '<<', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'<<'} = sub { term24($_[1], $_[0], $_[2], $_[3]) }; %}

# token term25 { { return { colon => '<<', _pos => [$/->from - 2, $/->to], } } }

%{ $rule_terms{'«'} = sub { term24($_[1], $_[0], $_[2], $_[3]) }; %}

token term26 {
        <.ws> <rule>
        { return {
            modifier => {
                modifier => 'ignorecase',
                rule => $$<rule>,
                }
            },
        }
}

%{ $rule_terms{':i'} = sub { term26($_[1], $_[0], $_[2], $_[3]) }; %}

#        <.ws> <rule>
#        { return { modifier => { modifier => 'ignorecase', :$$<rule> } } }
# }

%{ $rule_terms{':ignorecase'} = sub { term26($_[1], $_[0], $_[2], $_[3]) }; %}

token term28 {
        <.ws> <rule>
        { return { modifier => 'sigspace', rule => $$<rule> } }
}

%{ $rule_terms{':s'} = sub { term28($_[1], $_[0], $_[2], $_[3]) }; %}

# token term29 {
#        <.ws> <rule>
#        { return { modifier => 'sigspace',   :$$<rule> } }
# }

%{ $rule_terms{':sigspace'} = sub { term28($_[1], $_[0], $_[2], $_[3]) }; %}

token term30 {
        <.ws> <rule>
        { return { modifier => 'Perl5', rule => $$<rule> } }
}

%{ $rule_terms{':P5'} = sub { term30($_[1], $_[0], $_[2], $_[3]) }; %}

# token term31 {
#        <.ws> <rule>
#        { return { modifier => 'Perl5',  :$$<rule> } }
# }

%{ $rule_terms{':Perl5'} = sub { term30($_[1], $_[0], $_[2], $_[3]) }; %}

token term32 {
        <.ws> <rule>
        { return { modifier => 'bytes', rule => $$<rule> } }
}

%{ $rule_terms{':bytes'} = sub { term32($_[1], $_[0], $_[2], $_[3]) }; %}

token term33 {
        <.ws> <rule>
        { return { modifier => 'codes', rule => $$<rule> } }
}

%{ $rule_terms{':codes'} = sub { term33($_[1], $_[0], $_[2], $_[3]) }; %}

token term34 {
        <.ws> <rule>
        { return { modifier => 'graphs', rule => $$<rule> } }
}

%{ $rule_terms{':graphs'} = sub { term34($_[1], $_[0], $_[2], $_[3]) }; %}

token term35 {
        <.ws> <rule>
        { return { modifier => 'langs',  rule => $$<rule> } }
}

%{ $rule_terms{':langs'} = sub { term35($_[1], $_[0], $_[2], $_[3]) }; %}

token term {
    |  <%Pugs::Grammar::Rule::variables>
       [  <.ws>? ':=' <.ws>? <named_capture_body>
          {
            return { named_capture => {
                        rule =>  $$<named_capture_body>,
                        ident => $$<Pugs::Grammar::Rule::variables>,
                     },
                        _pos => [ $/->from, $/->to ],
                     };
          }
       |
          {
            return $$<Pugs::Grammar::Rule::variables>
          }
       ]
    |  <%Pugs::Grammar::Rule::rule_terms>
        {
            #print "term: ", Dumper( $_[0]->data );
            return $$<Pugs::Grammar::Rule::rule_terms>
        }
    |  <-[ \] \} \) \> \: \? \+ \* \| \& ]>
        {
            return { 'constant' => ${$/},
                     _pos => [ $/->from, $/->to ] }
        }
}

token quant {
    |   '**' <.ws>? \{  <parsed_code>  \}
        { return { closure => $$<parsed_code> } }
    |   <[  \? \* \+  ]>?
}

token quantifier {
    $<ws1>   := (<.ws>?)
    <!before  <[   \} \] \)   ]> >
    <term>
    $<ws2>   := (<.ws>?)
    <quant>
    $<greedy> := (<[  \? \+  ]>?)
    $<ws3>   := (<.ws>?)
    {
      if (
               ${$/{'quant'}}  eq ''
            && ${$/{'greedy'}} eq ''
            && ${$/{'ws1'}}    eq ''
            && ${$/{'ws2'}}    eq ''
            && ${$/{'ws3'}}    eq ''
      ) {
          return ${$/{'term'}};
      }
      return {
        quant => {
                term    => ${$/{'term'}},
                quant   => ${$/{'quant'}},
                greedy  => ${$/{'greedy'}},
                ws1     => ${$/{'ws1'}},
                ws2     => ${$/{'ws2'}},
                ws3     => ${$/{'ws3'}},
            },
        _pos => [$/->from, $/->to],
      }
    }
}

token concat {
    <quantifier>+
    {
        my @a = map {  $_->()  }  @{ $::_V6_MATCH_->{'quantifier'} };
        return { concat => \@a, _pos => [$/->from, $/->to] }
            if scalar @a > 1;
        return $a[0];
    }
}

token conjunctive1 {
    [ <.ws>? \& <!before \& > ]?

    <concat>**{1}
    [
        \& <!before \& >  <concat>
    ]*

    {
        my @a = map {  $$_  }  @{ $::_V6_MATCH_->{'concat'} };
        return { conjunctive1 => \@a, _pos => [$/->from, $/->to] }  if scalar @a > 1;
        return $a[0];
    }
}

token disjunctive1 {
    [ <.ws>? \| <!before \| > ]?

    <conjunctive1>**{1}
    [
        \| <!before \| > <conjunctive1>
    ]*

    {
        my @a = map {  $$_  }  @{ $::_V6_MATCH_->{'conjunctive1'} };
        return { alt1 => \@a, _pos => [$/->from, $/->to] }  if scalar @a > 1;
        return $a[0];
    }
}

token conjunctive {
    [ <.ws>? \& \& ]?

    <disjunctive1>**{1}
    [
        \& \& <disjunctive1>
    ]*

    {
        my @a = map {  $$_  }  @{ $::_V6_MATCH_->{'disjunctive1'} };
        return { conjunctive => \@a, _pos => [$/->from, $/->to] }  if scalar @a > 1;
        return $a[0];
    }
}

token rule {
    [ <.ws>? \| \| ]?

    <conjunctive>**{1}
    [
        \| \| <conjunctive>
    ]*

    {
        my @a = map {  $$_  }  @{ $::_V6_MATCH_->{'conjunctive'} };
        return { alt => \@a, _pos => [$/->from, $/->to], }  if scalar @a > 1;
        return $a[0];
    }
}

token named_regex {
    ( 'token' | 'regex' | 'rule' )
    <.ws> <ident> <.ws>? '{'
        <.ws>?
        <rule>
    '}' ';'?

    { return {
            type => $$0,
            name => $$<ident>,
            ast => $$<rule>
        };
    }
}

# This is hacky, will do better later
token verbatim {
    '%{' ( [ <!before '%}'> . ]* ) '%}'
    { return {
            type => 'block',
            value => $$0
        };
    }
}

token item {
    | <verbatim>       { return $$<verbatim>; }
    | <named_regex> { return $$<named_regex>; }
}

token grammar {
    <.ws>? 'grammar' <.ws> <ident> <.ws>? ';'
    <.ws>?
    [ <item> <.ws>? ]*
    { return { $$<ident> => $<item> } }
}

token spec {
    <verbatim>?
    <grammar>*
    { return {
            block => $<verbatim>,
            'grammar' => $<grammar> }
    }
}