grammar JSON {
    token TOP { ^ <object> $ }
    rule object { '{' <pairlist>? '}' }
    rule pairlist { <pair> [',' <pair>]* }
    rule pair { <string> ':' <value> }
    rule array { '[' <valuelist>? ']' }
    rule valuelist { <value> [',' <value>]* }
    rule value { <string> | <number> | <object> | <array> | 'true' | 'false' | 'null' }
    token string { '"' <strcontent>* '"' }
    token strcontent { \\ <strchar> | <uniesc> | <!before '"')> . }
    token strchar { <-[\\"\n]> }
    token uniesc { '\\u' <.xdigit> ** 4> }
    token number { '-'? \d+ [ '.' \d+ ]? [ <[eE]> [ <[+\-]>? \d+ ] ]? }
}