Tweak json.lua

json4lua/examples/example.lua

@@ -4,6 +4,9 @@ Demonstrates the simple functionality of the json module.
 ]]--
 json = require('json')
 
+-- lua 5.1+ compat
+local foreach = table.foreach or loadstring("local t,f = ... for k,v in pairs(t) do if f(k,v) ~= nil then break end end")
+
 
 -- Object to JSON encode
 test = {
@@ -18,6 +21,6 @@ print('JSON encoded test is: ' .. jsonTest)
 result = json.decode(jsonTest)
 
 print ("The decoded table result:")
-table.foreach(result,print)
+foreach(result, print)
 print ("The decoded table result.three")
-table.foreach(result.three, print)
+foreach(result.three, print)

json4lua/examples/tests.lua

@@ -121,7 +121,7 @@ function testJSON4Lua()
 
   s = [["Test\u00A7\\"]]
   r,e = json._decode_scanString(s,1)
-  assert(r=="Test\xC2\xA7\\" and e==9)
+  assert(r=="Test\194\167\\\"" and e==9)
   print(s,r)
 
   -- Test decode_scanNumber
@@ -162,10 +162,52 @@ function testJSON4Lua()
 
   end
 
+  -- Test string decoding
   s = [["Test\u00A7\\\""]]
+  r,e = json.decode(s)
+  assert(r=="Test\194\167\\\"")
+  print(s,r)
+
+  s = [["\\u"]]
+  r,e = json.decode(s)
+  assert(r=="\\u")
+  print(s,r)
+
+  s = [["\\"]]
   r,e = json.decode(s)
-  assert(r=="Test\xC2\xA7\\\"", r)
+  assert(r=="\\")
   print(s,r)
+
+  s = [["\v\///"]]
+  r,e = json.decode(s)
+  assert(r=="v///")
+  print(s,r)
+
+  -- Test invalid unicode escapes
+  s = [["\u000"]]
+  r,e = pcall(json.decode,s)
+  assert(not r and e)
+  print(s,r,e)
+
+  s = [["\u00"]]
+  r,e = pcall(json.decode,s)
+  assert(not r and e)
+  print(s,r,e)
+
+  s = [["\u0"]]
+  r,e = pcall(json.decode,s)
+  assert(not r and e)
+  print(s,r,e)
+
+  s = [["\u"]]
+  r,e = pcall(json.decode,s)
+  assert(not r and e)
+  print(s,r,e)
+
+  s = [["\uXXXX"]]
+  r,e = pcall(json.decode,s)
+  assert(not r and e)
+  print(s,r,e)
 
   -- Test decode_scanObject
   s = [[ {"one":1, "two":2, "three":"three", "four":true} ]]

json4lua/examples/timetrials.lua

@@ -1,11 +1,14 @@
 --[[
   Some Time Trails for the JSON4Lua package
-]]--
+--]]
 
 
 require('json')
 require('os')
 require('table')
+
+-- this is so we don't get shouted at for syntax errors
+local mod = math.mod or math.fmod or (loadstring or load)("local a,b = ... return a % b")
 
 local t1 = os.clock()
 local jstr
@@ -16,7 +19,7 @@ for i=1,100 do
     table.insert(t,j)
   end
   for j=1,500 do
-    table.insert(t,"VALUE")
+    table.insert(t,"VALUE\n\n\"\t")
   end
   jstr = json.encode(t)
   v = json.decode(jstr)
@@ -25,8 +28,8 @@ end
 
 for i = 1,100 do
   local t = {}
-  for j=1,500 do
-    local m= math.mod(j,3)
+  for j=1,500 do
+    local m = mod(j,3)
     if (m==0) then
       t['a'..j] = true
     elseif m==1 then 
@@ -39,8 +42,8 @@ for i = 1,100 do
   v = json.decode(jstr)
 end
 
-print (jstr)
+--print (jstr)
 --print(type(t1))
 local t2 = os.clock()
 
-print ("Elapsed time=" .. os.difftime(t2,t1) .. "s")
+print ("Elapsed time=" .. t2 - t1 .. "s")

json4lua/json/json.lua

@@ -38,7 +38,16 @@ local base = _G
 -----------------------------------------------------------------------------
 -- Module declaration
 -----------------------------------------------------------------------------
-module("json")
+local _ENV = _ENV
+local hasENV = false
+-- Check for Lua 5.2
+if not _ENV then
+  module("json")
+else
+  -- Use the new module system
+  hasENV = true
+end
+_ENV = {}
 
 -- Public functions
 
@@ -65,19 +74,19 @@ function encode (v)
   if v==nil then
     return "null"
   end
-  
+
   local vtype = base.type(v)  
 
   -- Handle strings
   if vtype=='string' then    
     return '"' .. encodeString(v) .. '"'	    -- Need to handle encoding in string
   end
-  
+
   -- Handle booleans
   if vtype=='number' or vtype=='boolean' then
     return base.tostring(v)
   end
-  
+
   -- Handle tables
   if vtype=='table' then
     local rval = {}
@@ -100,12 +109,12 @@ function encode (v)
       return '{' .. table.concat(rval,',') .. '}'
     end
   end
-  
+
   -- Handle null values
   if vtype=='function' and v==null then
     return 'null'
   end
-  
+
   base.assert(false,'encode attempt to encode unsupported type ' .. vtype .. ':' .. base.tostring(v))
 end
 
@@ -226,8 +235,8 @@ function decode_scanNumber(s,startPos)
   local stringLen = string.len(s)
   local acceptableChars = "+-0123456789.e"
   while (string.find(acceptableChars, string.sub(s,endPos,endPos), 1, true)
-	and endPos<=stringLen
-	) do
+    and endPos<=stringLen
+    ) do
     endPos = endPos + 1
   end
   local stringValue = 'return ' .. string.sub(s,startPos, endPos-1)
@@ -276,18 +285,21 @@ end
 -- Initialize some things used by decode_scanString
 -- You know, for efficiency
 local escapeSequences = {
-  ["\\t"] = "\t",
-  ["\\f"] = "\f",
-  ["\\r"] = "\r",
-  ["\\n"] = "\n",
-  ["\\b"] = "\b"
+  t = "\t",
+  f = "\f",
+  r = "\r",
+  n = "\n",
+  b = "\b"
+}
+local paddingSequences = {
+  u = "\\u"
 }
-base.setmetatable(escapeSequences, {__index = function(t,k)
-  -- skip "\" aka strip escape
-  return string.sub(k,2)
-end})
 -- END SoniEx2
 
+-- 5.0, 5.1, 5.2, 5.3+
+-- for _positive numbers_, math.fmod(a,b) == a % b
+local mod = math.mod or math.fmod or ((base.loadstring or base.load)("return function(a,b) return a % b end")())
+
 --- 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,
@@ -299,50 +311,58 @@ end})
 function decode_scanString(s,startPos)
   base.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
-  base.assert(startChar == [["]] or startChar == [[']],'decode_scanString called for a non-string')
-  --base.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
-      base.print(s, startPos, string.sub(s,startPos,oldj))
-      i,j = x,y-1
-      if not x then base.print(s, startPos, string.sub(s,startPos,oldj)) end
-    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 = base.tonumber(a, 16)
-      base.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))
+  base.assert(startChar==[[']] or startChar==[["]],'decode_scanString called for a non-string')
+  local escaped = false
+  local endPos = startPos + 1
+  local bEnded = false
+  local stringLen = string.len(s)
+  local stringLenAdd1 = stringLen + 1
+  repeat
+    if not escaped then
+      local curChar = string.sub(s,endPos,endPos)
+      if curChar==[[\]] then
+        escaped = true
       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))
+        bEnded = curChar==startChar
       end
-      table.insert(t, x)
-    else
-      table.insert(t, escapeSequences[string.sub(s, i, j)])
+    else
+      escaped = false
     end
+    endPos = endPos + 1
+    base.assert(endPos <= stringLenAdd1, "unfinished string")
+  until bEnded
+  --local stringValue = 'return ' .. string.sub(s, startPos, endPos-1)
+  --local stringEval = base.loadstring(stringValue)
+  --base.assert(stringEval, 'Failed to load string [ ' .. stringValue .. '] in JSON4Lua.decode_scanString at position ' .. startPos .. ' : ' .. endPos)
+  --return stringEval(), endPos
+  --return table.concat(t), endPos
+  local str = string.sub(s, startPos+1, endPos-2)
+  -- pad - we use a table here because we want to keep \u as \u
+  str = string.gsub(str, "\\(.)", function(x) return paddingSequences[x] or ("\\v" .. x .. "///") end)
+  if string.find(str, "\\u", -5) then
+    -- string end looks like `"...\uXXX"` or `"...\uXX"` or `"...\uX"` or even `"...\u"`
+    base.error("String decoding failed: bad Unicode escape")
   end
-  table.insert(t,string.sub(j, j+1))
-  base.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
+  str = string.gsub(str, "\\([vu])((.)...)",
+    function(a,b,c)
+      if a == "v" then
+        return escapeSequences[c] or c
+      else
+        local n = base.tonumber(b, 16)
+        base.assert(n, "String decoding failed: bad Unicode escape")
+        if n < 128 then
+          -- [0xxx xxxx] aka ASCII
+          return string.char(n)
+        elseif n < 2048 then
+          -- [110x xxxx] [10xx xxxx]
+          return string.char(192+math.floor(n/64),128+mod(n,64))
+        else
+          -- [1110 xxxx] [10xx xxxx] [10xx xxxx]
+          return string.char(224+math.floor(n/4096),128+mod(math.floor(n/64),64),128+mod(n, 64))
+        end
+      end
+    end)
+  return str, endPos
 end
 
 --- Scans a JSON string skipping all whitespace from the current start position.
@@ -366,18 +386,18 @@ end
 -- @return The string appropriately escaped.
 
 local escapeList = {
-    ['"']  = '\\"',
-    ['\\'] = '\\\\',
-    ['/']  = '\\/', 
-    ['\b'] = '\\b',
-    ['\f'] = '\\f',
-    ['\n'] = '\\n',
-    ['\r'] = '\\r',
-    ['\t'] = '\\t'
+  ['"']  = '\\"',
+  ['\\'] = '\\\\',
+  ['/']  = '\\/', 
+  ['\b'] = '\\b',
+  ['\f'] = '\\f',
+  ['\n'] = '\\n',
+  ['\r'] = '\\r',
+  ['\t'] = '\\t'
 }
 
 function encodeString(s)
- return s:gsub(".", function(c) return escapeList[c] end) -- SoniEx2: 5.0 compat
+  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.
@@ -417,3 +437,6 @@ function isEncodable(o)
   return (t=='string' or t=='boolean' or t=='number' or t=='nil' or t=='table') or (t=='function' and o==null) 
 end
 
+if hasENV then
+  return _ENV
+end