/*
 * This file contains a simple and quite possible wrong parser for
 * JSON encoded structures.
 *
 * It does not support white space in quoted strings, those are silently
 * dropped.
 *
 * It has primarily been written to parse video parameters from the
 * DailyMotion site
 *
 * Token definitions:
 *  COLON => ':',
 *  QUOTE => '\"',
 *  SINGLEQUOTE => '\\\'',
 *  TRUE => 'true',
 *  FALSE => 'false',
 *  NULL => 'null',
 *  QUADHEX => 'u[0-9a-fA-F]{4}',
 *  INTEGER => '[0-9]+',
 *  QUOTEDNORMAL => '[nr]',
 *  SIMPLECHAR => '[-a-zA-Z\._\?\+=\&\!%<>]+',
 *  BACKSLASH => '\\\\',
 *  SLASH => '/',
 *  COMMA => ',',
 *  CURLYOPEN => '{',
 *  CURLYCLOSE => '}',
 *  SQUAREOPEN => '\[',
 *  SQUARECLOSE => '\]',
 */

%{
use Encode;
%}
%%
    
basicstream:
    basictype { return [ $_[1] ] } |
    basicstream COMMA basictype { return [ @{$_[1]}, $_[3] ] };

basictype:
    hash |
    array |
    quotestring |
    boolean;

boolean:
    TRUE { return 1 } |
    FALSE { return 0 };

array:
    SQUAREOPEN SQUARECLOSE { return [] } |
    SQUAREOPEN basicstream SQUARECLOSE { return [ @{$_[2]} ] };

hash:
    CURLYOPEN CURLYCLOSE { return { } } |
    CURLYOPEN kvstream CURLYCLOSE { return { @{$_[2]} } };

kvstream:
    kvpair |
    kvstream COMMA kvpair { return [ @{$_[1]}, @{$_[3]} ] };

kvpair:
    quotestring COLON quotestring { return [ $_[1], $_[3] ] } |
    quotestring COLON hash { return [ $_[1], $_[3] ] } |
    quotestring COLON array { return [ $_[1], $_[3] ] } |
    quotestring COLON boolean { return [ $_[1], $_[3] ] } |
    quotestring COLON NULL { return [ $_[1], undef ] } |
    quotestring COLON INTEGER { return [ $_[1], $_[3] ] };

quotestring:
    QUOTE QUOTE { return "" } | 
    QUOTE charstream QUOTE { return $_[2] };

charstream:
    char |
    charstream char { return $_[1] . $_[2] };

escapedchar:
    BACKSLASH CURLYOPEN { return $_[2] } |
    BACKSLASH CURLYCLOSE { return $_[2] } |
    BACKSLASH SQUAREOPEN { return $_[2] } |
    BACKSLASH SQUARECLOSE { return $_[2] } |
    BACKSLASH QUOTE { return $_[2] } |
    BACKSLASH SINGLEQUOTE { return $_[2] } |
    BACKSLASH SLASH { return $_[2] } |
    BACKSLASH BACKSLASH { return $_[2] } |
    BACKSLASH QUADHEX { return encode("utf8", pack("U", hex(substr($_[2],1)))) } |
    BACKSLASH QUOTEDNORMAL {
        if ($_[2] eq 'n') {
            return "\n";
        } elsif ($_[2] eq 'r') {
            return "\r";
        } else {
            return $_[2];
        }};

char:
    QUOTEDNORMAL |
    U |
    QUADHEX |
    SIMPLECHAR | 
    INTEGER |
    COLON |
    COMMA |
    SINGLEQUOTE |
    TRUE |
    FALSE |
    NULL |
    SQUAREOPEN |
    SQUARECLOSE |
    escapedchar;

%%