+ # Parses and returns a Nit string from a JSON String
+ fun parse_json_string: Serializable do
+ var src = src
+ var ln = src.length
+ var p = pos
+ p += 1
+ if p > ln then return make_parse_error("Malformed JSON String")
+ var c = src[p]
+ var ret = parse_str_buf
+ var chunk_st = p
+ while c != '"' do
+ if c != '\\' then
+ p += 1
+ if p >= ln then return make_parse_error("Malformed JSON string")
+ c = src[p]
+ continue
+ end
+ ret.append_substring_impl(src, chunk_st, p - chunk_st)
+ p += 1
+ if p >= ln then return make_parse_error("Malformed Escape sequence in JSON string")
+ c = src[p]
+ if c == 'r' then
+ ret.add '\r'
+ p += 1
+ else if c == 'n' then
+ ret.add '\n'
+ p += 1
+ else if c == 't' then
+ ret.add '\t'
+ p += 1
+ else if c == 'u' then
+ var cp = 0
+ p += 1
+ for i in [0 .. 4[ do
+ cp <<= 4
+ if p >= ln then make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ c = src[p]
+ if c >= '0' and c <= '9' then
+ cp += c.code_point - '0'.code_point
+ else if c >= 'a' and c <= 'f' then
+ cp += c.code_point - 'a'.code_point + 10
+ else if c >= 'A' and c <= 'F' then
+ cp += c.code_point - 'A'.code_point + 10
+ else
+ make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ end
+ p += 1
+ end
+ c = cp.code_point
+ if cp >= 0xD800 and cp <= 0xDBFF then
+ if p >= ln then make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ c = src[p]
+ if c != '\\' then make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ p += 1
+ c = src[p]
+ if c != 'u' then make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ var locp = 0
+ p += 1
+ for i in [0 .. 4[ do
+ locp <<= 4
+ if p > ln then make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ c = src[p]
+ if c >= '0' and c <= '9' then
+ locp += c.code_point - '0'.code_point
+ else if c >= 'a' and c <= 'f' then
+ locp += c.code_point - 'a'.code_point + 10
+ else if c >= 'A' and c <= 'F' then
+ locp += c.code_point - 'A'.code_point + 10
+ else
+ make_parse_error("Malformed \uXXXX Escape sequence in JSON string")
+ end
+ p += 1
+ end
+ c = (((locp & 0x3FF) | ((cp & 0x3FF) << 10)) + 0x10000).code_point
+ end
+ ret.add c
+ else if c == 'b' then
+ ret.add 8.code_point
+ p += 1
+ else if c == 'f' then
+ ret.add '\f'
+ p += 1
+ else
+ p += 1
+ ret.add c
+ end
+ chunk_st = p
+ c = src[p]
+ end
+ pos = p + 1
+ if ret.is_empty then return src.substring(chunk_st, p - chunk_st)
+ ret.append_substring_impl(src, chunk_st, p - chunk_st)
+ var rets = ret.to_s
+ ret.clear
+ return rets
+ end