scope jsonDecode sO jsonDecode(S text) { ret new Y(text).parse(); } // the miraculous class Y sclass Y { S text; LS tok; bool useOrderedMaps; int i = 1; *(S *text) { tok = jsonTok(text); } swappable void fail(S msg) { main fail(msg); } O parse() { if (l(tok) == 1) null; ret parseExpr(); } O parseExpr() { String t = tok.get(i); if (t.startsWith("\"") || t.startsWith("'")) { String s = unquote(tok.get(i)); i += 2; return s; } if (t.equals("{")) return parseMap(); if (t.equals("[")) return this.parseList(); // avoid loading standard function "parseList" if (t.equals("null")) { i += 2; return null; } if (t.equals("false")) { i += 2; return false; } if (t.equals("true")) { i += 2; return true; } bool minus = false; if (t.equals("-")) { minus = true; i += 2; t = get(tok, i); } if (isInteger(t)) { int j = i; i += 2; if (eqOneOf(get(tok, i), ".", "e", "E")) { // rough parsing for doubles while (isInteger(get(tok, i)) || eqOneOf(get(tok, i), ".", "e", "E", "-")) i += 2; double d = parseDouble(joinSubList(tok, j, i-1)); if (minus) d = -d; ret d; } else { long l = parseLong(t); if (minus) l = -l; ret l != (int) l ? (O) new Long(l) : new Integer((int) l); } } fail("Unknown token " + (i+1) + ": " + t + ": " + text); } Object parseList() { consume("["); List list = new ArrayList; while (!tok.get(i).equals("]")) { list.add(parseExpr()); if (tok.get(i).equals(",")) i += 2; } consume("]"); return list; } Object parseMap() { consume("{"); Map map = useOrderedMaps ? new LinkedHashMap : new TreeMap; while (!tok.get(i).equals("}")) { String key = unquote(tok.get(i)); i += 2; consume(":"); Object value = parseExpr(); map.put(key, value); if (tok.get(i).equals(",")) i += 2; } consume("}"); return map; } void consume(String s) { if (!tok.get(i).equals(s)) { S prevToken = i-2 >= 0 ? tok.get(i-2) : ""; S nextTokens = join(tok.subList(i, Math.min(i+4, tok.size()))); fail(quote(s) + " expected: " + prevToken + " " + nextTokens + " (" + i + "/" + tok.size() + ")"); } i += 2; } }