diff options
Diffstat (limited to 'script-beta/json.lua')
| -rw-r--r-- | script-beta/json.lua | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/script-beta/json.lua b/script-beta/json.lua new file mode 100644 index 00000000..46261d7d --- /dev/null +++ b/script-beta/json.lua @@ -0,0 +1,450 @@ +local type = type +local next = next +local error = error +local tonumber = tonumber +local tostring = tostring +local utf8_char = utf8.char +local table_concat = table.concat +local table_sort = table.sort +local string_char = string.char +local string_byte = string.byte +local string_find = string.find +local string_match = string.match +local string_gsub = string.gsub +local string_sub = string.sub +local string_format = string.format +local math_type = math.type +local setmetatable = setmetatable +local getmetatable = getmetatable +local Inf = math.huge + +local json = {} +json.object = {} + +-- json.encode -- +local statusMark +local statusQue + +local encode_map = {} + +local encode_escape_map = { + [ "\"" ] = "\\\"", + [ "\\" ] = "\\\\", + [ "/" ] = "\\/", + [ "\b" ] = "\\b", + [ "\f" ] = "\\f", + [ "\n" ] = "\\n", + [ "\r" ] = "\\r", + [ "\t" ] = "\\t", +} + +local decode_escape_set = {} +local decode_escape_map = {} +for k, v in next, encode_escape_map do + decode_escape_map[v] = k + decode_escape_set[string_byte(v, 2)] = true +end + +for i = 0, 31 do + local c = string_char(i) + if not encode_escape_map[c] then + encode_escape_map[c] = string_format("\\u%04x", i) + end +end + +local function encode(v) + local res = encode_map[type(v)](v) + statusQue[#statusQue+1] = res +end + +encode_map["nil"] = function () + return "null" +end + +function encode_map.string(v) + return '"' .. string_gsub(v, '[\0-\31\\"]', encode_escape_map) .. '"' +end +local encode_string = encode_map.string + +local function convertreal(v) + local g = string_format('%.16g', v) + if tonumber(g) == v then + return g + end + return string_format('%.17g', v) +end + +function encode_map.number(v) + if v ~= v or v <= -Inf or v >= Inf then + error("unexpected number value '" .. tostring(v) .. "'") + end + return string_gsub(convertreal(v), ',', '.') +end + +function encode_map.boolean(v) + if v then + return "true" + else + return "false" + end +end + +function encode_map.table(t) + local first_val = next(t) + if first_val == nil then + if getmetatable(t) == json.object then + return "{}" + else + return "[]" + end + end + if statusMark[t] then + error("circular reference") + end + statusMark[t] = true + if type(first_val) == 'string' then + local key = {} + for k in next, t do + if type(k) ~= "string" then + error("invalid table: mixed or invalid key types") + end + key[#key+1] = k + end + table_sort(key) + statusQue[#statusQue+1] = "{" + local k = key[1] + statusQue[#statusQue+1] = encode_string(k) + statusQue[#statusQue+1] = ":" + encode(t[k]) + for i = 2, #key do + local k = key[i] + statusQue[#statusQue+1] = "," + statusQue[#statusQue+1] = encode_string(k) + statusQue[#statusQue+1] = ":" + encode(t[k]) + end + statusMark[t] = nil + return "}" + else + local max = 0 + for k in next, t do + if math_type(k) ~= "integer" or k <= 0 then + error("invalid table: mixed or invalid key types") + end + if max < k then + max = k + end + end + statusQue[#statusQue+1] = "[" + encode(t[1]) + for i = 2, max do + statusQue[#statusQue+1] = "," + encode(t[i]) + end + statusMark[t] = nil + return "]" + end +end + +local function encode_unexpected(v) + if v == json.null then + return "null" + else + error("unexpected type '"..type(v).."'") + end +end +encode_map[ "function" ] = encode_unexpected +encode_map[ "userdata" ] = encode_unexpected +encode_map[ "thread" ] = encode_unexpected + +function json.encode(v) + statusMark = {} + statusQue = {} + encode(v) + return table_concat(statusQue) +end + +json.encode_map = encode_map + +-- json.decode -- + +local statusBuf +local statusPos +local statusTop +local statusAry = {} +local statusRef = {} + +local function find_line() + local line = 1 + local pos = 1 + while true do + local f, _, nl1, nl2 = string_find(statusBuf, '([\n\r])([\n\r]?)', pos) + if not f then + return line, statusPos - pos + 1 + end + local newpos = f + ((nl1 == nl2 or nl2 == '') and 1 or 2) + if newpos > statusPos then + return line, statusPos - pos + 1 + end + pos = newpos + line = line + 1 + end +end + +local function decode_error(msg) + error(string_format("ERROR: %s at line %d col %d", msg, find_line())) +end + +local function get_word() + return string_match(statusBuf, "^[^ \t\r\n%]},]*", statusPos) +end + +local function next_byte() + statusPos = string_find(statusBuf, "[^ \t\r\n]", statusPos) + if statusPos then + return string_byte(statusBuf, statusPos) + end + statusPos = #statusBuf + 1 + decode_error("unexpected character '<eol>'") +end + +local function expect_byte(c) + local _, pos = string_find(statusBuf, c, statusPos) + if not pos then + decode_error(string_format("expected '%s'", string_sub(c, #c))) + end + statusPos = pos +end + +local function decode_unicode_surrogate(s1, s2) + return utf8_char(0x10000 + (tonumber(s1, 16) - 0xd800) * 0x400 + (tonumber(s2, 16) - 0xdc00)) +end + +local function decode_unicode_escape(s) + return utf8_char(tonumber(s, 16)) +end + +local function decode_string() + local has_unicode_escape = false + local has_escape = false + local i = statusPos + 1 + while true do + i = string_find(statusBuf, '["\\\0-\31]', i) + if not i then + decode_error "expected closing quote for string" + end + local x = string_byte(statusBuf, i) + if x < 32 then + statusPos = i + decode_error "control character in string" + end + if x == 34 --[[ '"' ]] then + local s = string_sub(statusBuf, statusPos + 1, i - 1) + if has_unicode_escape then + s = string_gsub(string_gsub(s + , "\\u([dD][89aAbB]%x%x)\\u([dD][c-fC-F]%x%x)", decode_unicode_surrogate) + , "\\u(%x%x%x%x)", decode_unicode_escape) + end + if has_escape then + s = string_gsub(s, "\\.", decode_escape_map) + end + statusPos = i + 1 + return s + end + --assert(x == 92 --[[ "\\" ]]) + local nx = string_byte(statusBuf, i+1) + if nx == 117 --[[ "u" ]] then + if not string_match(statusBuf, "^%x%x%x%x", i+2) then + statusPos = i + decode_error "invalid unicode escape in string" + end + has_unicode_escape = true + i = i + 6 + else + if not decode_escape_set[nx] then + statusPos = i + decode_error("invalid escape char '" .. (nx and string_char(nx) or "<eol>") .. "' in string") + end + has_escape = true + i = i + 2 + end + end +end + +local function decode_number() + local word = get_word() + if not ( + string_match(word, '^.[0-9]*$') + or string_match(word, '^.[0-9]*%.[0-9]+$') + or string_match(word, '^.[0-9]*[Ee][+-]?[0-9]+$') + or string_match(word, '^.[0-9]*%.[0-9]+[Ee][+-]?[0-9]+$') + ) then + decode_error("invalid number '" .. word .. "'") + end + statusPos = statusPos + #word + return tonumber(word) +end + +local function decode_number_negative() + local word = get_word() + if not ( + string_match(word, '^.[1-9][0-9]*$') + or string_match(word, '^.[1-9][0-9]*%.[0-9]+$') + or string_match(word, '^.[1-9][0-9]*[Ee][+-]?[0-9]+$') + or string_match(word, '^.[1-9][0-9]*%.[0-9]+[Ee][+-]?[0-9]+$') + or word == "-0" + or string_match(word, '^.0%.[0-9]+$') + or string_match(word, '^.0[Ee][+-]?[0-9]+$') + or string_match(word, '^.0%.[0-9]+[Ee][+-]?[0-9]+$') + ) then + decode_error("invalid number '" .. word .. "'") + end + statusPos = statusPos + #word + return tonumber(word) +end + +local function decode_number_zero() + local word = get_word() + if not ( + #word == 1 + or string_match(word, '^.%.[0-9]+$') + or string_match(word, '^.[Ee][+-]?[0-9]+$') + or string_match(word, '^.%.[0-9]+[Ee][+-]?[0-9]+$') + ) then + decode_error("invalid number '" .. word .. "'") + end + statusPos = statusPos + #word + return tonumber(word) +end + +local function decode_true() + if string_sub(statusBuf, statusPos, statusPos+3) ~= "true" then + decode_error("invalid literal '" .. get_word() .. "'") + end + statusPos = statusPos + 4 + return true +end + +local function decode_false() + if string_sub(statusBuf, statusPos, statusPos+4) ~= "false" then + decode_error("invalid literal '" .. get_word() .. "'") + end + statusPos = statusPos + 5 + return false +end + +local function decode_null() + if string_sub(statusBuf, statusPos, statusPos+3) ~= "null" then + decode_error("invalid literal '" .. get_word() .. "'") + end + statusPos = statusPos + 4 + return json.null +end + +local function decode_array() + statusPos = statusPos + 1 + local res = {} + if next_byte() == 93 --[[ "]" ]] then + statusPos = statusPos + 1 + return res + end + statusTop = statusTop + 1 + statusAry[statusTop] = true + statusRef[statusTop] = res + return res +end + +local function decode_object() + statusPos = statusPos + 1 + local res = {} + if next_byte() == 125 --[[ "}" ]] then + statusPos = statusPos + 1 + return setmetatable(res, json.object) + end + statusTop = statusTop + 1 + statusAry[statusTop] = false + statusRef[statusTop] = res + return res +end + +local decode_uncompleted_map = { + [ string_byte '"' ] = decode_string, + [ string_byte "0" ] = decode_number_zero, + [ string_byte "1" ] = decode_number, + [ string_byte "2" ] = decode_number, + [ string_byte "3" ] = decode_number, + [ string_byte "4" ] = decode_number, + [ string_byte "5" ] = decode_number, + [ string_byte "6" ] = decode_number, + [ string_byte "7" ] = decode_number, + [ string_byte "8" ] = decode_number, + [ string_byte "9" ] = decode_number, + [ string_byte "-" ] = decode_number_negative, + [ string_byte "t" ] = decode_true, + [ string_byte "f" ] = decode_false, + [ string_byte "n" ] = decode_null, + [ string_byte "[" ] = decode_array, + [ string_byte "{" ] = decode_object, +} +local function unexpected_character() + decode_error("unexpected character '" .. string_sub(statusBuf, statusPos, statusPos) .. "'") +end + +local decode_map = {} +for i = 0, 255 do + decode_map[i] = decode_uncompleted_map[i] or unexpected_character +end + +local function decode() + return decode_map[next_byte()]() +end + +local function decode_item() + local top = statusTop + local ref = statusRef[top] + if statusAry[top] then + ref[#ref+1] = decode() + else + expect_byte '^[ \t\r\n]*"' + local key = decode_string() + expect_byte '^[ \t\r\n]*:' + statusPos = statusPos + 1 + ref[key] = decode() + end + if top == statusTop then + repeat + local chr = next_byte(); statusPos = statusPos + 1 + if chr == 44 --[[ "," ]] then + return + end + if statusAry[statusTop] then + if chr ~= 93 --[[ "]" ]] then decode_error "expected ']' or ','" end + else + if chr ~= 125 --[[ "}" ]] then decode_error "expected '}' or ','" end + end + statusTop = statusTop - 1 + until statusTop == 0 + end +end + +function json.decode(str) + if type(str) ~= "string" then + error("expected argument of type string, got " .. type(str)) + end + statusBuf = str + statusPos = 1 + statusTop = 0 + local res = decode() + while statusTop > 0 do + decode_item() + end + if string_find(statusBuf, "[^ \t\r\n]", statusPos) then + decode_error "trailing garbage" + end + return res +end + +-- Generate a lightuserdata +json.null = debug.upvalueid(decode, 1) + +return json |