From 636aaed7ccf734aed36e04e8b739e153689c7aa2 Mon Sep 17 00:00:00 2001
From: Francois Perrad <francois.perrad@gadz.org>
Date: Thu, 23 Mar 2017 15:26:46 +0100
Subject: [PATCH] backport math.type from 5.3

---
 src/lib_math.c | 15 +++++++++++++++
 src/lj_api.c   |  6 ++++++
 src/lua.h      |  2 ++
 3 files changed, 23 insertions(+)

diff --git a/src/lib_math.c b/src/lib_math.c
index ef9dda2d..073a628a 100644
--- a/src/lib_math.c
+++ b/src/lib_math.c
@@ -94,6 +94,21 @@ LJLIB_ASM(math_min)		LJLIB_REC(math_minmax IR_MIN)
 }
 LJLIB_ASM_(math_max)		LJLIB_REC(math_minmax IR_MAX)
 
+LJLIB_CF(math_type)
+{
+  if (lua_type(L, 1) == LUA_TNUMBER) {
+      if (lua_isinteger(L, 1))
+        lua_pushliteral(L, "integer");
+      else
+        lua_pushliteral(L, "float");
+  }
+  else {
+    luaL_checkany(L, 1);
+    lua_pushnil(L);
+  }
+  return 1;
+}
+
 LJLIB_PUSH(3.14159265358979323846) LJLIB_SET(pi)
 LJLIB_PUSH(1e310) LJLIB_SET(huge)
 
diff --git a/src/lj_api.c b/src/lj_api.c
index d1be3abf..f1c704da 100644
--- a/src/lj_api.c
+++ b/src/lj_api.c
@@ -231,6 +231,12 @@ LUA_API int lua_iscfunction(lua_State *L, int idx)
   return tvisfunc(o) && !isluafunc(funcV(o));
 }
 
+LUA_API int lua_isinteger (lua_State *L, int idx) {
+  cTValue *o = index2adr(L, idx);
+  return tvisint(o) ||
+        (tvisnumber(o) && ((lua_Number)(lua_Integer)numV(o) == numV(o)));
+}
+
 LUA_API int lua_isnumber(lua_State *L, int idx)
 {
   cTValue *o = index2adr(L, idx);
diff --git a/src/lua.h b/src/lua.h
index 352d29f3..bee120ef 100644
--- a/src/lua.h
+++ b/src/lua.h
@@ -347,6 +347,8 @@ LUA_API void *lua_upvalueid (lua_State *L, int idx, int n);
 LUA_API void lua_upvaluejoin (lua_State *L, int idx1, int n1, int idx2, int n2);
 LUA_API int lua_loadx (lua_State *L, lua_Reader reader, void *dt,
 		       const char *chunkname, const char *mode);
+/* From Lua 5.3. */
+LUA_API int lua_isinteger (lua_State *L, int idx);
 
 
 struct lua_Debug {