Added option to change radix for floating numbers (closes #36, closes #37).

This is needed to produce a valid Lua code when a local locale setting
makes `format` to produce floating point numbers with a comma.

Limitation: only commas are being fixed in floating point numbers.

README.md

@@ -69,6 +69,7 @@ Similar to `pcall` and `loadstring` calls, `load` returns status as the first va
 * sparse (true/false) -- force sparse encoding (no nil filling based on `#t`).
 * compact (true/false) -- remove spaces.
 * fatal (true/False) -- raise fatal error on non-serilizable values.
+* fixradix (true/False) -- change radix character set depending on locale to decimal dot.
 * nocode (true/False) -- disable bytecode serialization for easy comparison.
 * nohuge (true/False) -- disable checking numbers against undefined and huge values.
 * maxlevel (number) -- specify max level up to which to expand nested tables.

src/serpent.lua

@@ -1,4 +1,4 @@
-local n, v = "serpent", "0.302" -- (C) 2012-18 Paul Kulchenko; MIT License
+local n, v = "serpent", "0.303" -- (C) 2012-18 Paul Kulchenko; MIT License
 local c, d = "Paul Kulchenko", "Lua serializer and pretty printer"
 local snum = {[tostring(1/0)]='1/0 --[[math.huge]]',[tostring(-1/0)]='-1/0 --[[-math.huge]]',[tostring(0/0)]='0/0'}
 local badtype = {thread = true, userdata = true, cdata = true}
@@ -23,9 +23,16 @@ local function s(t, opts)
   local function gensym(val) return '_'..(tostring(tostring(val)):gsub("[^%w]",""):gsub("(%d%w+)",
     -- tostring(val) is needed because __tostring may return a non-string value
     function(s) if not syms[s] then symn = symn+1; syms[s] = symn end return tostring(syms[s]) end)) end
-  local function safestr(s) return type(s) == "number" and tostring(huge and snum[tostring(s)] or numformat:format(s))
+  local function safestr(s) return type(s) == "number" and (huge and snum[tostring(s)] or numformat:format(s))
     or type(s) ~= "string" and tostring(s) -- escape NEWLINE/010 and EOF/026
     or ("%q"):format(s):gsub("\010","n"):gsub("\026","\\026") end
+  -- handle radix changes in some locales
+  if opts.fixradix and (".1f"):format(1.2) ~= "1.2" then
+    local origsafestr = safestr
+    safestr = function(s) return type(s) == "number"
+      and (nohuge and snum[tostring(s)] or numformat:format(s):gsub(",",".")) or origsafestr(s)
+    end
+  end
   local function comment(s,l) return comm and (l or 0) < comm and ' --[['..select(2, pcall(tostring, s))..']]' or '' end
   local function globerr(s,l) return globals[s] and globals[s]..comment(s,l) or not fatal
     and safestr(select(2, pcall(tostring, s))) or error("Can't serialize "..tostring(s)) end

t/test.lua

@@ -328,13 +328,23 @@ end
 do
   local a = serpent.line({ pi = math.pi })
   local ok, t = serpent.load(a)
-  assert(ok, "pi is serialized and deserialized (1/2): failed")
+  assert(ok, "pi is serialized and deserialized (1/3): failed")
-  assert(math.pi == t.pi, "pi is deserialized with the same value as the original (1/2): failed")
+  assert(math.pi == t.pi, "pi is deserialized with the same value as the original (1/3): failed")
 
   a = serpent.line({pi = math.pi}, {numformat = "%1.16e"})
   ok, t = serpent.load(a)
-  assert(ok, "pi is serialized and deserialized (2/2): failed")
+  assert(ok, "pi is serialized and deserialized (2/3): failed")
-  assert(math.pi == t.pi, "pi is deserialized with the same value as the original with '%1.16e' format (2/2): failed")
+  assert(math.pi == t.pi, "pi is deserialized with the same value as the original with '%1.16e' format (2/3): failed")
+
+  local locale = os.setlocale()
+  os.setlocale("German_Germany")
+
+  a = serpent.line({pi = math.pi}, {fixradix = true})
+  ok, t = serpent.load(a)
+  assert(ok, "pi is serialized and deserialized with fr_FR locale (3/3): failed")
+  assert(math.pi == t.pi, "pi is deserialized with the same value as the original with fr_FR locale (3/3): failed")
+
+  os.setlocale(locale)
 end
 
 -- based on https://gist.github.com/mpeterv/8360307