Added pkg-config to Makefile.

Makefile

@@ -2,20 +2,22 @@
 
 FC      = gfortran
 AR      = ar
-FFLAGS  = -Wall
+FFLAGS  = -Wall `pkg-config --cflags lua-5.3`
 ARFLAGS = rcs
-LDFLAGS = -I/usr/local/include/lua53/ -L/usr/local/lib/lua/5.3/
-LDLIBS  = -llua-5.3
+LDFLAGS = `pkg-config --libs-only-L lua-5.3`
+LDLIBS  = `pkg-config --libs-only-l lua-5.3`
 TARGET  = libfortran-lua53.a
 
 FIBONACCI = examples/fibonacci/fibonacci
 LIBRARY   = examples/library/fortran.so
 STRING    = examples/string/string
 TABLE     = examples/table/table
 
-.PHONY: all clean
+.PHONY: all clean examples
 
-all: $(TARGET) $(FIBONACCI) $(LIBRARY) $(STRING) $(TABLE)
+all: $(TARGET)
+
+examples: $(FIBONACCI) $(LIBRARY) $(STRING) $(TABLE)
 
 $(TARGET):
 	$(FC) $(FFLAGS) -fPIC -c src/lua.f90

examples/table/table.f90

@@ -13,7 +13,9 @@ program main
     call lual_openlibs(l)            ! Open Lua standard library.
     rc = lual_dofile(l, 'table.lua') ! Open Lua file.
     rc = lua_pcall(l, 0, 0, 0)       ! Run the script once.
-    rc = lua_getglobal(l, 'a')       ! Get the table.
+
+    ! Get the table.
+    rc = lua_getglobal(l, 'a')
 
     if (lua_istable(l, -1) == 1) then
         ! Get table field.

src/lua.f90

@@ -10,9 +10,6 @@ module lua
     implicit none
     private
 
-    integer, parameter, public :: lua_integer = c_int
-    integer, parameter, public :: lua_number  = c_double
-
     public :: lua_arith
     public :: lua_call
     public :: lua_callk
@@ -83,6 +80,9 @@ module lua
     private :: c_f_str_ptr
     private :: copy
 
+    integer, parameter, public :: lua_integer = c_int
+    integer, parameter, public :: lua_number  = c_double
+
     ! Option for multiple returns in `lua_pcall()` and `lua_call()`.
     integer(kind=c_int), parameter, public :: LUA_MULTRET = -1
 
@@ -793,7 +793,7 @@ end function lua_tonumber
     ! const char *lua_tostring(lua_State *L, int index)
     function lua_tostring(l, i)
         !! Wrapper that calls `lua_tolstring()` and converts the returned C
-        !! pointer to Fortran string.
+        !! pointer to Fortran string. Returns an unallocated character on error.
         type(c_ptr), intent(in)       :: l
         integer,     intent(in)       :: i
         character(len=:), allocatable :: lua_tostring
@@ -807,7 +807,7 @@ end function lua_tostring
     ! const char *lua_typename(lua_State *L, int tp)
     function lua_typename(l, tp)
         !! Wrapper that calls `lua_typename_()` and converts the returned C
-        !! pointer to Fortran string.
+        !! pointer to Fortran string. Returns an unallocated character on error.
         type(c_ptr), intent(in)       :: l
         integer,     intent(in)       :: tp
         character(len=:), allocatable :: lua_typename