From 30f2f46474bf4eda5f10d4c64a07cde01d469f66 Mon Sep 17 00:00:00 2001 From: chai Date: Mon, 15 Nov 2021 11:54:17 +0800 Subject: *rename DefaultContent -> BuiltIn --- Data/BuiltIn/Libraries/json4lua/json/json.lua | 427 ++++++++++++++++++++++++++ 1 file changed, 427 insertions(+) create mode 100644 Data/BuiltIn/Libraries/json4lua/json/json.lua (limited to 'Data/BuiltIn/Libraries/json4lua/json/json.lua') diff --git a/Data/BuiltIn/Libraries/json4lua/json/json.lua b/Data/BuiltIn/Libraries/json4lua/json/json.lua new file mode 100644 index 0000000..79761b6 --- /dev/null +++ b/Data/BuiltIn/Libraries/json4lua/json/json.lua @@ -0,0 +1,427 @@ +----------------------------------------------------------------------------- +-- JSON4Lua: JSON encoding / decoding support for the Lua language. +-- json Module. +-- Author: Craig Mason-Jones +-- Homepage: http://github.com/craigmj/json4lua/ +-- Version: 1.0.0 +-- This module is released under the MIT License (MIT). +-- Please see LICENCE.txt for details. +-- +-- USAGE: +-- This module exposes two functions: +-- json.encode(o) +-- Returns the table / string / boolean / number / nil / json.null value as a JSON-encoded string. +-- json.decode(json_string) +-- Returns a Lua object populated with the data encoded in the JSON string json_string. +-- +-- REQUIREMENTS: +-- compat-5.1 if using Lua 5.0 +-- +-- CHANGELOG +-- 0.9.20 Introduction of local Lua functions for private functions (removed _ function prefix). +-- Fixed Lua 5.1 compatibility issues. +-- Introduced json.null to have null values in associative arrays. +-- json.encode() performance improvement (more than 50%) through table.concat rather than .. +-- Introduced decode ability to ignore /**/ comments in the JSON string. +-- 0.9.10 Fix to array encoding / decoding to correctly manage nil/null values in arrays. +----------------------------------------------------------------------------- + +----------------------------------------------------------------------------- +-- Imports and dependencies +----------------------------------------------------------------------------- +local math = require('math') +local string = require("string") +local table = require("table") + +----------------------------------------------------------------------------- +-- Module declaration +----------------------------------------------------------------------------- +local json = {} -- Public namespace +local json_private = {} -- Private namespace + +-- Public constants +json.EMPTY_ARRAY={} +json.EMPTY_OBJECT={} + +-- Public functions + +-- Private functions +local decode_scanArray +local decode_scanComment +local decode_scanConstant +local decode_scanNumber +local decode_scanObject +local decode_scanString +local decode_scanWhitespace +local encodeString +local isArray +local isEncodable + +----------------------------------------------------------------------------- +-- PUBLIC FUNCTIONS +----------------------------------------------------------------------------- +--- Encodes an arbitrary Lua object / variable. +-- @param v The Lua object / variable to be JSON encoded. +-- @return String containing the JSON encoding in internal Lua string format (i.e. not unicode) +function json.encode (v) + -- Handle nil values + if v==nil then + return "null" + end + + local vtype = type(v) + + -- Handle strings + if vtype=='string' then + return '"' .. json_private.encodeString(v) .. '"' -- Need to handle encoding in string + end + + -- Handle booleans + if vtype=='number' or vtype=='boolean' then + return tostring(v) + end + + -- Handle tables + if vtype=='table' then + local rval = {} + -- Consider arrays separately + local bArray, maxCount = isArray(v) + if bArray then + for i = 1,maxCount do + table.insert(rval, json.encode(v[i])) + end + else -- An object, not an array + for i,j in pairs(v) do + if isEncodable(i) and isEncodable(j) then + table.insert(rval, '"' .. json_private.encodeString(i) .. '":' .. json.encode(j)) + end + end + end + if bArray then + return '[' .. table.concat(rval,',') ..']' + else + return '{' .. table.concat(rval,',') .. '}' + end + end + + -- Handle null values + if vtype=='function' and v==json.null then + return 'null' + end + + assert(false,'encode attempt to encode unsupported type ' .. vtype .. ':' .. tostring(v)) +end + + +--- Decodes a JSON string and returns the decoded value as a Lua data structure / value. +-- @param s The string to scan. +-- @param [startPos] Optional starting position where the JSON string is located. Defaults to 1. +-- @param Lua object, number The object that was scanned, as a Lua table / string / number / boolean or nil, +-- and the position of the first character after +-- the scanned JSON object. +function json.decode(s, startPos) + startPos = startPos and startPos or 1 + startPos = decode_scanWhitespace(s,startPos) + assert(startPos<=string.len(s), 'Unterminated JSON encoded object found at position in [' .. s .. ']') + local curChar = string.sub(s,startPos,startPos) + -- Object + if curChar=='{' then + return decode_scanObject(s,startPos) + end + -- Array + if curChar=='[' then + return decode_scanArray(s,startPos) + end + -- Number + if string.find("+-0123456789.e", curChar, 1, true) then + return decode_scanNumber(s,startPos) + end + -- String + if curChar==[["]] or curChar==[[']] then + return decode_scanString(s,startPos) + end + if string.sub(s,startPos,startPos+1)=='/*' then + return json.decode(s, decode_scanComment(s,startPos)) + end + -- Otherwise, it must be a constant + return decode_scanConstant(s,startPos) +end + +--- The null function allows one to specify a null value in an associative array (which is otherwise +-- discarded if you set the value with 'nil' in Lua. Simply set t = { first=json.null } +function json.null() + return json.null -- so json.null() will also return null ;-) +end +----------------------------------------------------------------------------- +-- Internal, PRIVATE functions. +-- Following a Python-like convention, I have prefixed all these 'PRIVATE' +-- functions with an underscore. +----------------------------------------------------------------------------- + +--- Scans an array from JSON into a Lua object +-- startPos begins at the start of the array. +-- Returns the array and the next starting position +-- @param s The string being scanned. +-- @param startPos The starting position for the scan. +-- @return table, int The scanned array as a table, and the position of the next character to scan. +function decode_scanArray(s,startPos) + local array = {} -- The return value + local stringLen = string.len(s) + assert(string.sub(s,startPos,startPos)=='[','decode_scanArray called but array does not start at position ' .. startPos .. ' in string:\n'..s ) + startPos = startPos + 1 + -- Infinite loop for array elements + local index = 1 + repeat + startPos = decode_scanWhitespace(s,startPos) + assert(startPos<=stringLen,'JSON String ended unexpectedly scanning array.') + local curChar = string.sub(s,startPos,startPos) + if (curChar==']') then + return array, startPos+1 + end + if (curChar==',') then + startPos = decode_scanWhitespace(s,startPos+1) + end + assert(startPos<=stringLen, 'JSON String ended unexpectedly scanning array.') + object, startPos = json.decode(s,startPos) + array[index] = object + index = index + 1 + until false +end + +--- Scans a comment and discards the comment. +-- Returns the position of the next character following the comment. +-- @param string s The JSON string to scan. +-- @param int startPos The starting position of the comment +function decode_scanComment(s, startPos) + assert( string.sub(s,startPos,startPos+1)=='/*', "decode_scanComment called but comment does not start at position " .. startPos) + local endPos = string.find(s,'*/',startPos+2) + assert(endPos~=nil, "Unterminated comment in string at " .. startPos) + return endPos+2 +end + +--- Scans for given constants: true, false or null +-- Returns the appropriate Lua type, and the position of the next character to read. +-- @param s The string being scanned. +-- @param startPos The position in the string at which to start scanning. +-- @return object, int The object (true, false or nil) and the position at which the next character should be +-- scanned. +function decode_scanConstant(s, startPos) + local consts = { ["true"] = true, ["false"] = false, ["null"] = nil } + local constNames = {"true","false","null"} + + for i,k in pairs(constNames) do + if string.sub(s,startPos, startPos + string.len(k) -1 )==k then + return consts[k], startPos + string.len(k) + end + end + assert(nil, 'Failed to scan constant from string ' .. s .. ' at starting position ' .. startPos) +end + +--- Scans a number from the JSON encoded string. +-- (in fact, also is able to scan numeric +- eqns, which is not +-- in the JSON spec.) +-- Returns the number, and the position of the next character +-- after the number. +-- @param s The string being scanned. +-- @param startPos The position at which to start scanning. +-- @return number, int The extracted number and the position of the next character to scan. +function decode_scanNumber(s,startPos) + local endPos = startPos+1 + local stringLen = string.len(s) + local acceptableChars = "+-0123456789.e" + while (string.find(acceptableChars, string.sub(s,endPos,endPos), 1, true) + and endPos<=stringLen + ) do + endPos = endPos + 1 + end + local stringValue = 'return ' .. string.sub(s,startPos, endPos-1) + local stringEval = load(stringValue) + assert(stringEval, 'Failed to scan number [ ' .. stringValue .. '] in JSON string at position ' .. startPos .. ' : ' .. endPos) + return stringEval(), endPos +end + +--- Scans a JSON object into a Lua object. +-- startPos begins at the start of the object. +-- Returns the object and the next starting position. +-- @param s The string being scanned. +-- @param startPos The starting position of the scan. +-- @return table, int The scanned object as a table and the position of the next character to scan. +function decode_scanObject(s,startPos) + local object = {} + local stringLen = string.len(s) + local key, value + assert(string.sub(s,startPos,startPos)=='{','decode_scanObject called but object does not start at position ' .. startPos .. ' in string:\n' .. s) + startPos = startPos + 1 + repeat + startPos = decode_scanWhitespace(s,startPos) + assert(startPos<=stringLen, 'JSON string ended unexpectedly while scanning object.') + local curChar = string.sub(s,startPos,startPos) + if (curChar=='}') then + return object,startPos+1 + end + if (curChar==',') then + startPos = decode_scanWhitespace(s,startPos+1) + end + assert(startPos<=stringLen, 'JSON string ended unexpectedly scanning object.') + -- Scan the key + key, startPos = json.decode(s,startPos) + assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key) + startPos = decode_scanWhitespace(s,startPos) + assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key) + assert(string.sub(s,startPos,startPos)==':','JSON object key-value assignment mal-formed at ' .. startPos) + startPos = decode_scanWhitespace(s,startPos+1) + assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key) + value, startPos = json.decode(s,startPos) + object[key]=value + until false -- infinite loop while key-value pairs are found +end + +-- START SoniEx2 +-- Initialize some things used by decode_scanString +-- You know, for efficiency +local escapeSequences = { + ["\\t"] = "\t", + ["\\f"] = "\f", + ["\\r"] = "\r", + ["\\n"] = "\n", + ["\\b"] = "\b" +} +setmetatable(escapeSequences, {__index = function(t,k) + -- skip "\" aka strip escape + return string.sub(k,2) +end}) +-- END SoniEx2 + +--- Scans a JSON string from the opening inverted comma or single quote to the +-- end of the string. +-- Returns the string extracted as a Lua string, +-- and the position of the next non-string character +-- (after the closing inverted comma or single quote). +-- @param s The string being scanned. +-- @param startPos The starting position of the scan. +-- @return string, int The extracted string as a Lua string, and the next character to parse. +function decode_scanString(s,startPos) + assert(startPos, 'decode_scanString(..) called without start position') + local startChar = string.sub(s,startPos,startPos) + -- START SoniEx2 + -- PS: I don't think single quotes are valid JSON + assert(startChar == [["]] or startChar == [[']],'decode_scanString called for a non-string') + --assert(startPos, "String decoding failed: missing closing " .. startChar .. " for string at position " .. oldStart) + local t = {} + local i,j = startPos,startPos + while string.find(s, startChar, j+1) ~= j+1 do + local oldj = j + i,j = string.find(s, "\\.", j+1) + local x,y = string.find(s, startChar, oldj+1) + if not i or x < i then + i,j = x,y-1 + end + table.insert(t, string.sub(s, oldj+1, i-1)) + if string.sub(s, i, j) == "\\u" then + local a = string.sub(s,j+1,j+4) + j = j + 4 + local n = tonumber(a, 16) + assert(n, "String decoding failed: bad Unicode escape " .. a .. " at position " .. i .. " : " .. j) + -- math.floor(x/2^y) == lazy right shift + -- a % 2^b == bitwise_and(a, (2^b)-1) + -- 64 = 2^6 + -- 4096 = 2^12 (or 2^6 * 2^6) + local x + if n < 0x80 then + x = string.char(n % 0x80) + elseif n < 0x800 then + -- [110x xxxx] [10xx xxxx] + x = string.char(0xC0 + (math.floor(n/64) % 0x20), 0x80 + (n % 0x40)) + else + -- [1110 xxxx] [10xx xxxx] [10xx xxxx] + x = string.char(0xE0 + (math.floor(n/4096) % 0x10), 0x80 + (math.floor(n/64) % 0x40), 0x80 + (n % 0x40)) + end + table.insert(t, x) + else + table.insert(t, escapeSequences[string.sub(s, i, j)]) + end + end + table.insert(t,string.sub(j, j+1)) + assert(string.find(s, startChar, j+1), "String decoding failed: missing closing " .. startChar .. " at position " .. j .. "(for string at position " .. startPos .. ")") + return table.concat(t,""), j+2 + -- END SoniEx2 +end + +--- Scans a JSON string skipping all whitespace from the current start position. +-- Returns the position of the first non-whitespace character, or nil if the whole end of string is reached. +-- @param s The string being scanned +-- @param startPos The starting position where we should begin removing whitespace. +-- @return int The first position where non-whitespace was encountered, or string.len(s)+1 if the end of string +-- was reached. +function decode_scanWhitespace(s,startPos) + local whitespace=" \n\r\t" + local stringLen = string.len(s) + while ( string.find(whitespace, string.sub(s,startPos,startPos), 1, true) and startPos <= stringLen) do + startPos = startPos + 1 + end + return startPos +end + +--- Encodes a string to be JSON-compatible. +-- This just involves back-quoting inverted commas, back-quotes and newlines, I think ;-) +-- @param s The string to return as a JSON encoded (i.e. backquoted string) +-- @return The string appropriately escaped. + +local escapeList = { + ['"'] = '\\"', + ['\\'] = '\\\\', + ['/'] = '\\/', + ['\b'] = '\\b', + ['\f'] = '\\f', + ['\n'] = '\\n', + ['\r'] = '\\r', + ['\t'] = '\\t' +} + +function json_private.encodeString(s) + local s = tostring(s) + return s:gsub(".", function(c) return escapeList[c] end) -- SoniEx2: 5.0 compat +end + +-- Determines whether the given Lua type is an array or a table / dictionary. +-- We consider any table an array if it has indexes 1..n for its n items, and no +-- other data in the table. +-- I think this method is currently a little 'flaky', but can't think of a good way around it yet... +-- @param t The table to evaluate as an array +-- @return boolean, number True if the table can be represented as an array, false otherwise. If true, +-- the second returned value is the maximum +-- number of indexed elements in the array. +function isArray(t) + -- Next we count all the elements, ensuring that any non-indexed elements are not-encodable + -- (with the possible exception of 'n') + if (t == json.EMPTY_ARRAY) then return true, 0 end + if (t == json.EMPTY_OBJECT) then return false end + + local maxIndex = 0 + for k,v in pairs(t) do + if (type(k)=='number' and math.floor(k)==k and 1<=k) then -- k,v is an indexed pair + if (not isEncodable(v)) then return false end -- All array elements must be encodable + maxIndex = math.max(maxIndex,k) + else + if (k=='n') then + if v ~= (t.n or #t) then return false end -- False if n does not hold the number of elements + else -- Else of (k=='n') + if isEncodable(v) then return false end + end -- End of (k~='n') + end -- End of k,v not an indexed pair + end -- End of loop across all pairs + return true, maxIndex +end + +--- Determines whether the given Lua object / table / variable can be JSON encoded. The only +-- types that are JSON encodable are: string, boolean, number, nil, table and json.null. +-- In this implementation, all other types are ignored. +-- @param o The object to examine. +-- @return boolean True if the object should be JSON encoded, false if it should be ignored. +function isEncodable(o) + local t = type(o) + return (t=='string' or t=='boolean' or t=='number' or t=='nil' or t=='table') or + (t=='function' and o==json.null) +end + +return json -- cgit v1.1-26-g67d0