lua/json/decode/state.lua

   1 --[[
   2         Licensed according to the included 'LICENSE' document
   3         Author: Thomas Harning Jr <harningt@gmail.com>
   4 ]]
   5
   6 local setmetatable = setmetatable
   7 local jsonutil = require("json.util")
   8 local assert = assert
   9 local type = type
  10 local next = next
  11 local unpack = unpack
  12
  13 _ENV = nil
  14
  15 local state_ops = {}
  16 local state_mt = {
  17         __index = state_ops
  18 }
  19
  20 function state_ops.pop(self)
  21         self.previous_set = true
  22         self.previous = self.active
  23         local i = self.i
  24         -- Load in this array into the active item
  25         self.active = self.stack[i]
  26         self.active_state = self.state_stack[i]
  27         self.active_key = self.key_stack[i]
  28         self.stack[i] = nil
  29         self.state_stack[i] = nil
  30         self.key_stack[i] = nil
  31
  32         self.i = i - 1
  33 end
  34
  35 function state_ops.push(self)
  36         local i = self.i + 1
  37         self.i = i
  38
  39         self.stack[i] = self.active
  40         self.state_stack[i] = self.active_state
  41         self.key_stack[i] = self.active_key
  42 end
  43
  44 function state_ops.put_object_value(self, trailing)
  45         local object_options = self.options.object
  46         if trailing and object_options.trailingComma then
  47                 if not self.active_key then
  48                         return
  49                 end
  50         end
  51         assert(self.active_key, "Missing key value")
  52         object_options.setObjectKey(self.active, self.active_key, self:grab_value())
  53         self.active_key = nil
  54 end
  55
  56 function state_ops.put_array_value(self, trailing)
  57         -- Safety check
  58         if trailing and not self.previous_set and self.options.array.trailingComma then
  59                 return
  60         end
  61         local new_index = self.active_state + 1
  62         self.active_state = new_index
  63         self.active[new_index] = self:grab_value()
  64 end
  65
  66 function state_ops.put_value(self, trailing)
  67         if self.active_state == 'object' then
  68                 self:put_object_value(trailing)
  69         else
  70                 self:put_array_value(trailing)
  71         end
  72 end
  73
  74 function state_ops.new_array(self)
  75         local new_array = {}
  76         if jsonutil.InitArray then
  77                 new_array = jsonutil.InitArray(new_array) or new_array
  78         end
  79         self.active = new_array
  80         self.active_state = 0
  81         self.active_key = nil
  82         self:unset_value()
  83 end
  84
  85 function state_ops.end_array(self)
  86         if self.previous_set or self.active_state ~= 0 then
  87                 -- Not an empty array
  88                 self:put_value(true)
  89         end
  90         if self.active_state ~= #self.active then
  91                 -- Store the length in
  92                 self.active.n = self.active_state
  93         end
  94 end
  95
  96 function state_ops.new_object(self)
  97         local new_object = {}
  98         self.active = new_object
  99         self.active_state = 'object'
 100         self.active_key = nil
 101         self:unset_value()
 102 end
 103
 104 function state_ops.end_object(self)
 105         if self.previous_set or next(self.active) then
 106                 -- Not an empty object
 107                 self:put_value(true)
 108         end
 109 end
 110
 111 function state_ops.new_call(self, name, func)
 112         -- TODO setup properly
 113         local new_call = {}
 114         new_call.name = name
 115         new_call.func = func
 116         self.active = new_call
 117         self.active_state = 0
 118         self.active_key = nil
 119         self:unset_value()
 120 end
 121
 122 function state_ops.end_call(self)
 123         if self.previous_set or self.active_state ~= 0 then
 124                 -- Not an empty array
 125                 self:put_value(true)
 126         end
 127         if self.active_state ~= #self.active then
 128                 -- Store the length in
 129                 self.active.n = self.active_state
 130         end
 131         local func = self.active.func
 132         if func == true then
 133                 func = jsonutil.buildCall
 134         end
 135         self.active = func(self.active.name, unpack(self.active, 1, self.active.n or #self.active))
 136 end
 137
 138
 139 function state_ops.unset_value(self)
 140         self.previous_set = false
 141         self.previous = nil
 142 end
 143
 144 function state_ops.grab_value(self)
 145         assert(self.previous_set, "Previous value not set")
 146         self.previous_set = false
 147         return self.previous
 148 end
 149
 150 function state_ops.set_value(self, value)
 151         assert(not self.previous_set, "Value set when one already in slot")
 152         self.previous_set = true
 153         self.previous = value
 154 end
 155
 156 function state_ops.set_key(self)
 157         assert(self.active_state == 'object', "Cannot set key on array")
 158         local value = self:grab_value()
 159         local value_type = type(value)
 160         if self.options.object.number then
 161                 assert(value_type == 'string' or value_type == 'number', "As configured, a key must be a number or string")
 162         else
 163                 assert(value_type == 'string', "As configured, a key must be a string")
 164         end
 165         self.active_key = value
 166 end
 167
 168
 169 local function create(options)
 170         local ret = {
 171                 options = options,
 172                 stack = {},
 173                 state_stack = {},
 174                 key_stack = {},
 175                 i = 0,
 176                 active = nil,
 177                 active_key = nil,
 178                 previous = nil,
 179                 active_state = nil
 180
 181         }
 182         return setmetatable(ret, state_mt)
 183 end
 184
 185 local state = {
 186         create = create
 187 }
 188
 189 return state