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Diffstat (limited to '')
| -rw-r--r-- | json.lua | 388 | ||||
| -rwxr-xr-x | lclipd.lua | 1 |
2 files changed, 389 insertions, 0 deletions
diff --git a/json.lua b/json.lua new file mode 100644 index 0000000..711ef78 --- /dev/null +++ b/json.lua @@ -0,0 +1,388 @@ +-- +-- json.lua +-- +-- Copyright (c) 2020 rxi +-- +-- Permission is hereby granted, free of charge, to any person obtaining a copy of +-- this software and associated documentation files (the "Software"), to deal in +-- the Software without restriction, including without limitation the rights to +-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies +-- of the Software, and to permit persons to whom the Software is furnished to do +-- so, subject to the following conditions: +-- +-- The above copyright notice and this permission notice shall be included in all +-- copies or substantial portions of the Software. +-- +-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +-- SOFTWARE. +-- + +local json = { _version = "0.1.2" } + +------------------------------------------------------------------------------- +-- Encode +------------------------------------------------------------------------------- + +local encode + +local escape_char_map = { + [ "\\" ] = "\\", + [ "\"" ] = "\"", + [ "\b" ] = "b", + [ "\f" ] = "f", + [ "\n" ] = "n", + [ "\r" ] = "r", + [ "\t" ] = "t", +} + +local escape_char_map_inv = { [ "/" ] = "/" } +for k, v in pairs(escape_char_map) do + escape_char_map_inv[v] = k +end + + +local function escape_char(c) + return "\\" .. (escape_char_map[c] or string.format("u%04x", c:byte())) +end + + +local function encode_nil(val) + return "null" +end + + +local function encode_table(val, stack) + local res = {} + stack = stack or {} + + -- Circular reference? + if stack[val] then error("circular reference") end + + stack[val] = true + + if rawget(val, 1) ~= nil or next(val) == nil then + -- Treat as array -- check keys are valid and it is not sparse + local n = 0 + for k in pairs(val) do + if type(k) ~= "number" then + error("invalid table: mixed or invalid key types") + end + n = n + 1 + end + if n ~= #val then + error("invalid table: sparse array") + end + -- Encode + for i, v in ipairs(val) do + table.insert(res, encode(v, stack)) + end + stack[val] = nil + return "[" .. table.concat(res, ",") .. "]" + + else + -- Treat as an object + for k, v in pairs(val) do + if type(k) ~= "string" then + error("invalid table: mixed or invalid key types") + end + table.insert(res, encode(k, stack) .. ":" .. encode(v, stack)) + end + stack[val] = nil + return "{" .. table.concat(res, ",") .. "}" + end +end + + +local function encode_string(val) + return '"' .. val:gsub('[%z\1-\31\\"]', escape_char) .. '"' +end + + +local function encode_number(val) + -- Check for NaN, -inf and inf + if val ~= val or val <= -math.huge or val >= math.huge then + error("unexpected number value '" .. tostring(val) .. "'") + end + return string.format("%.14g", val) +end + + +local type_func_map = { + [ "nil" ] = encode_nil, + [ "table" ] = encode_table, + [ "string" ] = encode_string, + [ "number" ] = encode_number, + [ "boolean" ] = tostring, +} + + +encode = function(val, stack) + local t = type(val) + local f = type_func_map[t] + if f then + return f(val, stack) + end + error("unexpected type '" .. t .. "'") +end + + +function json.encode(val) + return ( encode(val) ) +end + + +------------------------------------------------------------------------------- +-- Decode +------------------------------------------------------------------------------- + +local parse + +local function create_set(...) + local res = {} + for i = 1, select("#", ...) do + res[ select(i, ...) ] = true + end + return res +end + +local space_chars = create_set(" ", "\t", "\r", "\n") +local delim_chars = create_set(" ", "\t", "\r", "\n", "]", "}", ",") +local escape_chars = create_set("\\", "/", '"', "b", "f", "n", "r", "t", "u") +local literals = create_set("true", "false", "null") + +local literal_map = { + [ "true" ] = true, + [ "false" ] = false, + [ "null" ] = nil, +} + + +local function next_char(str, idx, set, negate) + for i = idx, #str do + if set[str:sub(i, i)] ~= negate then + return i + end + end + return #str + 1 +end + + +local function decode_error(str, idx, msg) + local line_count = 1 + local col_count = 1 + for i = 1, idx - 1 do + col_count = col_count + 1 + if str:sub(i, i) == "\n" then + line_count = line_count + 1 + col_count = 1 + end + end + error( string.format("%s at line %d col %d", msg, line_count, col_count) ) +end + + +local function codepoint_to_utf8(n) + -- http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=iws-appendixa + local f = math.floor + if n <= 0x7f then + return string.char(n) + elseif n <= 0x7ff then + return string.char(f(n / 64) + 192, n % 64 + 128) + elseif n <= 0xffff then + return string.char(f(n / 4096) + 224, f(n % 4096 / 64) + 128, n % 64 + 128) + elseif n <= 0x10ffff then + return string.char(f(n / 262144) + 240, f(n % 262144 / 4096) + 128, + f(n % 4096 / 64) + 128, n % 64 + 128) + end + error( string.format("invalid unicode codepoint '%x'", n) ) +end + + +local function parse_unicode_escape(s) + local n1 = tonumber( s:sub(1, 4), 16 ) + local n2 = tonumber( s:sub(7, 10), 16 ) + -- Surrogate pair? + if n2 then + return codepoint_to_utf8((n1 - 0xd800) * 0x400 + (n2 - 0xdc00) + 0x10000) + else + return codepoint_to_utf8(n1) + end +end + + +local function parse_string(str, i) + local res = "" + local j = i + 1 + local k = j + + while j <= #str do + local x = str:byte(j) + + if x < 32 then + decode_error(str, j, "control character in string") + + elseif x == 92 then -- `\`: Escape + res = res .. str:sub(k, j - 1) + j = j + 1 + local c = str:sub(j, j) + if c == "u" then + local hex = str:match("^[dD][89aAbB]%x%x\\u%x%x%x%x", j + 1) + or str:match("^%x%x%x%x", j + 1) + or decode_error(str, j - 1, "invalid unicode escape in string") + res = res .. parse_unicode_escape(hex) + j = j + #hex + else + if not escape_chars[c] then + decode_error(str, j - 1, "invalid escape char '" .. c .. "' in string") + end + res = res .. escape_char_map_inv[c] + end + k = j + 1 + + elseif x == 34 then -- `"`: End of string + res = res .. str:sub(k, j - 1) + return res, j + 1 + end + + j = j + 1 + end + + decode_error(str, i, "expected closing quote for string") +end + + +local function parse_number(str, i) + local x = next_char(str, i, delim_chars) + local s = str:sub(i, x - 1) + local n = tonumber(s) + if not n then + decode_error(str, i, "invalid number '" .. s .. "'") + end + return n, x +end + + +local function parse_literal(str, i) + local x = next_char(str, i, delim_chars) + local word = str:sub(i, x - 1) + if not literals[word] then + decode_error(str, i, "invalid literal '" .. word .. "'") + end + return literal_map[word], x +end + + +local function parse_array(str, i) + local res = {} + local n = 1 + i = i + 1 + while 1 do + local x + i = next_char(str, i, space_chars, true) + -- Empty / end of array? + if str:sub(i, i) == "]" then + i = i + 1 + break + end + -- Read token + x, i = parse(str, i) + res[n] = x + n = n + 1 + -- Next token + i = next_char(str, i, space_chars, true) + local chr = str:sub(i, i) + i = i + 1 + if chr == "]" then break end + if chr ~= "," then decode_error(str, i, "expected ']' or ','") end + end + return res, i +end + + +local function parse_object(str, i) + local res = {} + i = i + 1 + while 1 do + local key, val + i = next_char(str, i, space_chars, true) + -- Empty / end of object? + if str:sub(i, i) == "}" then + i = i + 1 + break + end + -- Read key + if str:sub(i, i) ~= '"' then + decode_error(str, i, "expected string for key") + end + key, i = parse(str, i) + -- Read ':' delimiter + i = next_char(str, i, space_chars, true) + if str:sub(i, i) ~= ":" then + decode_error(str, i, "expected ':' after key") + end + i = next_char(str, i + 1, space_chars, true) + -- Read value + val, i = parse(str, i) + -- Set + res[key] = val + -- Next token + i = next_char(str, i, space_chars, true) + local chr = str:sub(i, i) + i = i + 1 + if chr == "}" then break end + if chr ~= "," then decode_error(str, i, "expected '}' or ','") end + end + return res, i +end + + +local char_func_map = { + [ '"' ] = parse_string, + [ "0" ] = parse_number, + [ "1" ] = parse_number, + [ "2" ] = parse_number, + [ "3" ] = parse_number, + [ "4" ] = parse_number, + [ "5" ] = parse_number, + [ "6" ] = parse_number, + [ "7" ] = parse_number, + [ "8" ] = parse_number, + [ "9" ] = parse_number, + [ "-" ] = parse_number, + [ "t" ] = parse_literal, + [ "f" ] = parse_literal, + [ "n" ] = parse_literal, + [ "[" ] = parse_array, + [ "{" ] = parse_object, +} + + +parse = function(str, idx) + local chr = str:sub(idx, idx) + local f = char_func_map[chr] + if f then + return f(str, idx) + end + decode_error(str, idx, "unexpected character '" .. chr .. "'") +end + + +function json.decode(str) + if type(str) ~= "string" then + error("expected argument of type string, got " .. type(str)) + end + local res, idx = parse(str, next_char(str, 1, space_chars, true)) + idx = next_char(str, idx, space_chars, true) + if idx <= #str then + decode_error(str, idx, "trailing garbage") + end + return res +end + + +return json @@ -40,6 +40,7 @@ local posix_wait = require("posix.sys.wait") local libgen = require("posix.libgen") -- we have a vendored dependency +-- https://github.com/rxi/json.lua local base_path = libgen.dirname(arg[0]) package.path = package.path .. ";" .. base_path .. "/?.lua" local json = require("json") |