xqerl

Definitions.

BOM       = (\x{FFFE}|\x{FEFF}|\x{0000})
S         = (\r|\n|\v|\t|\s)*
QM        = [\x{0022}]
%AP        = [\x{0027}]

ESCAPE    = [\x{005C}]
HEXDIG4   = ([0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f][0-9A-Fa-f])
UNESCAPED = [\x{0020}-\x{0021}\x{0023}-\x{005B}\x{005D}-\x{10FFFF}]
ESCAPED   = ({ESCAPE}\x{0022}|{ESCAPE}\x{005C}|{ESCAPE}\x{002F}|{ESCAPE}\x{0062}|{ESCAPE}\x{0066}|{ESCAPE}\x{006E}|{ESCAPE}\x{0072}|{ESCAPE}\x{0074}|{ESCAPE}\x{0075}{HEXDIG4})

UCHAR  = ({UNESCAPED})*
CHAR   = ({UNESCAPED}|{ESCAPED})*
USTRING = {QM}{UCHAR}{QM}
STRING  = {QM}{CHAR}{QM}

Rules.
% string

{USTRING} : {token,{string ,TokenLine,TokenChars }}. 
{STRING} :  {token,{esc_string ,TokenLine,TokenChars }}. 

% values

false : {token,{false,TokenLine,false}}.
true  : {token,{true,TokenLine,true}}.
null  : {token,{null,TokenLine,null}}.
% number

[\-]?(0|([1-9][0-9]*))(\.[0-9]+)?([eE](\+|\-)?[0-9]+)? : {token,{number,TokenLine,TokenChars}}.
% structure

{S}\[{S} : {token,{array_begin ,TokenLine,array_begin }}.
{S}\]{S} : {token,{array_end   ,TokenLine,array_end   }}.
{S}\{{S} : {token,{object_begin,TokenLine,object_begin}}.
{S}\}{S} : {token,{object_end  ,TokenLine,object_end  }}.
{S}\:{S} : {token,{name_sep    ,TokenLine,name_sep    }}.
{S}\,{S} : {token,{value_sep   ,TokenLine,value_sep   }}.
{BOM}    : skip_token.

Erlang code.