Fixed bug re serializing variables named 'true' or 'false'

Author: nickgammon

lua/serialize.lua

@@ -8,6 +8,9 @@ module (..., package.seeall)
 -- See "Programming In Lua" chapter 12.1.2.
 -- Also see forum thread:
 --   http://www.gammon.com.au/forum/?id=4960
+
+-- Amended 7th April 2020 to fix bug re serializing variables
+--   named 'true' or 'false'
 -- ----------------------------------------------------------
 
 --[[
@@ -16,7 +19,7 @@ module (..., package.seeall)
 
   require "serialize"
   SetVariable ("mobs", serialize.save ("mobs"))  --> serialize mobs table
-  loadstring (GetVariable ("mobs")) ()  --> restore mobs table 
+  loadstring (GetVariable ("mobs")) ()  --> restore mobs table
 
   If you need to serialize two tables where subsequent ones refer to earlier ones
   you can supply your own "saved tables" variable, like this:
@@ -26,10 +29,10 @@ module (..., package.seeall)
     result = result .. "\n" .. serialize.save ("quests", nil, t)
 
   In this example the serializing of "quests" also knows about the "mobs" table
-  and will use references to it where necessary.  
+  and will use references to it where necessary.
 
   You can also supply the actual variable if the variable to be serialized does
-  not exist in the global namespace (for instance, if the variable is a local 
+  not exist in the global namespace (for instance, if the variable is a local
   variable to a function). eg.
 
      require "serialize"
@@ -42,17 +45,17 @@ module (..., package.seeall)
   because it would not be found in the _G namespace.
 
   ----- Added on 19 July 2007:
-  
+
   You can now do a "simple save" which is intended for tables without cycles. That is,
   tables, that do not refer to other tables. This is appropriate for "simple" data, like
   a straight table of keys/values, including subtables.
-  
+
   For a simple save, all you need to do is supply the value, like this:
-  
+
   print (serialize.save_simple ({ foo = 22, bar = "hi", t = { s = 9, k = 22 } }))
-  
+
   This produces:
-  
+
   {
   t = {
     s = 9,
@@ -61,7 +64,7 @@ module (..., package.seeall)
   bar = "hi",
   foo = 22,
   }
-  
+
 --]]
 
 local save_item  -- forward declaration, function appears near the end
@@ -72,12 +75,12 @@ function save (what, v, saved)
   saved = saved or {} -- initial table of tables we have already done
   v = v or _G [what]  -- default to "what" in global namespace
 
-  assert (type (what) == "string", 
+  assert (type (what) == "string",
           "1st argument to serialize.save should be the *name* of a variable")
-  
+
   assert (v, "Variable '" .. what .. "' does not exist")
 
-  assert (type (saved) == "table" or saved == nil, 
+  assert (type (saved) == "table" or saved == nil,
           "3rd argument to serialize.save should be a table or nil")
 
   local out = {}  -- output to this table
@@ -88,7 +91,7 @@ end -- serialize.save
 function save_simple (v)
   local out = {}  -- output to this table
   save_item_simple (v, out, 2)   -- do serialization
-  return table.concat (out)   -- turn into a string 
+  return table.concat (out)   -- turn into a string
 end -- serialize.save_simple
 
 --- below are local functions for this module -------------
@@ -99,7 +102,7 @@ local function basicSerialize (o)
   else   -- assume it is a string
     return string.format("%q", o)
   end
-end -- basicSerialize 
+end -- basicSerialize
 
 --
 -- Lua keywords might look OK to not be quoted as keys but must be.
@@ -109,22 +112,22 @@ end -- basicSerialize
 local lua_reserved_words = {}
 
 for _, v in ipairs ({
-    "and", "break", "do", "else", "elseif", "end", 
-    "for", "function", "if", "in", "local", "nil", "not", "or", 
-    "repeat", "return", "then",  "until", "while"
+    "and", "break", "do", "else", "elseif", "end",
+    "for", "function", "if", "in", "local", "nil", "not", "or",
+    "repeat", "return", "then",  "until", "while", "true", "false"
             }) do lua_reserved_words [v] = true end
 
 -- ----------------------------------------------------------
 -- save one variable (calls itself recursively)
--- 
+--
 -- Modified on 23 October 2005 to better handle keys (like table keys)
 -- ----------------------------------------------------------
 function save_item (name, value, out, indent, saved)  -- important! no "local" keyword
   local iname = string.rep (" ", indent) .. name -- indented name
 
   -- numbers, strings, and booleans can be simply serialized
 
-  if type (value) == "number" or 
+  if type (value) == "number" or
      type (value) == "string" or
      type (value) == "boolean" then
     table.insert (out, iname .. " = " .. basicSerialize(value))
@@ -141,31 +144,31 @@ function save_item (name, value, out, indent, saved)  -- important! no "local" k
       saved [value] = name   -- save name for next time
 
   -- make the table constructor, and recurse to save its contents
-  
+
       table.insert (out, iname .. " = {}")   -- create a new table
 
       for k, v in pairs (value) do      -- save its fields
-        local fieldname 
+        local fieldname
 
         -- if key is a Lua variable name which is not a reserved word
         -- we can express it as tablename.keyname
 
         if type (k) == "string"
-           and string.find (k, "^[_%a][_%a%d]*$") 
+           and string.find (k, "^[_%a][_%a%d]*$")
            and not lua_reserved_words [k] then
           fieldname = string.format("%s.%s", name, k)
 
         -- if key is a table itself, and we know its name then we can use that
         --  eg. tablename [ tablekeyname ]
 
         elseif type (k) == "table" and saved[k] then
-          fieldname = string.format("%s[%s]", name, saved [k]) 
+          fieldname = string.format("%s[%s]", name, saved [k])
 
         -- if key is an unknown table, we have to raise an error as we cannot
         -- deduce its name
- 
+
         elseif type (k) == "table" then
-          error ("Key table entry " .. tostring (k) .. 
+          error ("Key table entry " .. tostring (k) ..
                  " in table " .. name .. " is not known")
 
         -- if key is a number or a boolean it can simply go in brackets,
@@ -175,7 +178,7 @@ function save_item (name, value, out, indent, saved)  -- important! no "local" k
           fieldname = string.format("%s[%s]", name, tostring (k))
 
         -- now key should be a string, otherwise an error
- 
+
         elseif type (k) ~= "string" then
           error ("Cannot serialize table keys of type '" .. type (k) ..
                  "' in table " .. name)
@@ -185,13 +188,13 @@ function save_item (name, value, out, indent, saved)  -- important! no "local" k
 
         else
           fieldname  = string.format("%s[%s]", name,
-                                        basicSerialize(k))  
+                                        basicSerialize(k))
         end
 
         -- now we have finally worked out a suitable name for the key,
         -- recurse to save the value associated with it
 
-        save_item(fieldname, v, out, indent + 2, saved) 
+        save_item(fieldname, v, out, indent + 2, saved)
       end
     end
 
@@ -200,13 +203,13 @@ function save_item (name, value, out, indent, saved)  -- important! no "local" k
   else
     error ("Cannot serialize '" .. name .. "' (" .. type (value) .. ")")
   end  -- if type of variable
-end  -- save_item 
+end  -- save_item
 
 -- saves tables *without* cycles (produces smaller output)
 function save_item_simple (value, out, indent)
   -- numbers, strings, and booleans can be simply serialized
 
-  if type (value) == "number" or 
+  if type (value) == "number" or
      type (value) == "string" or
      type (value) == "boolean" then
     table.insert (out, basicSerialize(value))
@@ -215,23 +218,23 @@ function save_item_simple (value, out, indent)
 
     for k, v in pairs (value) do      -- save its fields
       table.insert (out, string.rep (" ", indent))
-      if not string.find (k, '^[_%a][_%a%d]*$') 
+      if not string.find (k, '^[_%a][_%a%d]*$')
          or lua_reserved_words [k] then
            table.insert (out, "[" .. basicSerialize (k) .. "] = ")
       else
         table.insert (out, k .. " = ")
       end -- if
-      save_item_simple (v, out, indent + 2)   
+      save_item_simple (v, out, indent + 2)
       table.insert (out, ",\n")
     end -- for each table item
-      
+
     table.insert (out, string.rep (" ", indent) .. "}")
-    
+
   -- cannot serialize things like functions, threads
 
   else
     error ("Cannot serialize " .. type (value))
   end  -- if type of variable
-  
+
 end -- save_item_simple