You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
121 lines
2.9 KiB
JavaScript
121 lines
2.9 KiB
JavaScript
/* JSON parser based on the grammar described at http://json.org/. */
|
|
|
|
/* ===== Syntactical Elements ===== */
|
|
|
|
start
|
|
= _ object:object { return object; }
|
|
|
|
object
|
|
= "{" _ "}" _ { return {}; }
|
|
/ "{" _ members:members "}" _ { return members; }
|
|
|
|
members
|
|
= head:pair tail:("," _ pair)* {
|
|
var result = {};
|
|
result[head[0]] = head[1];
|
|
for (var i = 0; i < tail.length; i++) {
|
|
result[tail[i][2][0]] = tail[i][2][1];
|
|
}
|
|
return result;
|
|
}
|
|
|
|
pair
|
|
= name:string ":" _ value:value { return [name, value]; }
|
|
|
|
array
|
|
= "[" _ "]" _ { return []; }
|
|
/ "[" _ elements:elements "]" _ { return elements; }
|
|
|
|
elements
|
|
= head:value tail:("," _ value)* {
|
|
var result = [head];
|
|
for (var i = 0; i < tail.length; i++) {
|
|
result.push(tail[i][2]);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
value
|
|
= string
|
|
/ number
|
|
/ object
|
|
/ array
|
|
/ "true" _ { return true; }
|
|
/ "false" _ { return false; }
|
|
// FIXME: We can't return null here because that would mean parse failure.
|
|
/ "null" _ { return "null"; }
|
|
|
|
/* ===== Lexical Elements ===== */
|
|
|
|
string "string"
|
|
= '"' '"' _ { return ""; }
|
|
/ '"' chars:chars '"' _ { return chars; }
|
|
|
|
chars
|
|
= chars:char+ { return chars.join(""); }
|
|
|
|
char
|
|
// In the original JSON grammar: "any-Unicode-character-except-"-or-\-or-control-character"
|
|
= [^"\\\0-\x1F\x7f]
|
|
/ '\\"' { return '"'; }
|
|
/ "\\\\" { return "\\"; }
|
|
/ "\\/" { return "/"; }
|
|
/ "\\b" { return "\b"; }
|
|
/ "\\f" { return "\f"; }
|
|
/ "\\n" { return "\n"; }
|
|
/ "\\r" { return "\r"; }
|
|
/ "\\t" { return "\t"; }
|
|
/ "\\u" h1:hexDigit h2:hexDigit h3:hexDigit h4:hexDigit {
|
|
return String.fromCharCode(parseInt("0x" + h1 + h2 + h3 + h4));
|
|
}
|
|
|
|
number "number"
|
|
= int_:int frac:frac exp:exp _ { return parseFloat(int_ + frac + exp); }
|
|
/ int_:int frac:frac _ { return parseFloat(int_ + frac); }
|
|
/ int_:int exp:exp _ { return parseFloat(int_ + exp); }
|
|
/ int_:int _ { return parseFloat(int_); }
|
|
|
|
int
|
|
= digit19:digit19 digits:digits { return digit19 + digits; }
|
|
/ digit:digit
|
|
/ "-" digit19:digit19 digits:digits { return "-" + digit19 + digits; }
|
|
/ "-" digit:digit { return "-" + digit; }
|
|
|
|
frac
|
|
= "." digits:digits { return "." + digits; }
|
|
|
|
exp
|
|
= e:e digits:digits { return e + digits; }
|
|
|
|
digits
|
|
= digits:digit+ { return digits.join(""); }
|
|
|
|
e
|
|
= e:[eE] sign:[+-]? { return e + sign; }
|
|
|
|
/*
|
|
* The following rules are not present in the original JSON gramar, but they are
|
|
* assumed to exist implicitly.
|
|
*
|
|
* FIXME: Define them according to ECMA-262, 5th ed.
|
|
*/
|
|
|
|
digit
|
|
= [0-9]
|
|
|
|
digit19
|
|
= [1-9]
|
|
|
|
hexDigit
|
|
= [0-9a-fA-F]
|
|
|
|
/* ===== Whitespace ===== */
|
|
|
|
_ "whitespace"
|
|
= whitespace*
|
|
|
|
// Whitespace is undefined in the original JSON grammar, so I assume a simple
|
|
// conventional definition consistent with ECMA-262, 5th ed.
|
|
whitespace
|
|
= [ \t\n\r]
|