Merge pull request #9 from spc476/master

Handle missing modules (lgi and lcurses);
Supports Lua 5.1 and Lua 5.2.

src/abstk.lua

@@ -8,8 +8,15 @@
 
 local abstk = {}
 
-local AbsGtk = require 'abstk.AbsGtk'
-local AbsCurses = require 'abstk.AbsCurses'
+local AbsGtk
+local AbsCurses
+
+do
+   local has_gtk, gtk_module = pcall(require,'abstk.AbsGtk')
+   local has_curses, curses_module = pcall(require,'abstk.AbsCurses')
+   if has_gtk then AbsGtk = gtk_module end
+   if has_curses then AbsCurses = curses_module end
+end
 
 local mode = nil
 
@@ -24,7 +31,7 @@ local mode = nil
 function abstk.set_mode(arg)
    if arg == 'curses' or arg == 'gtk' then
       mode = arg
-   elseif os.getenv("DISPLAY") then
+   elseif os.getenv("DISPLAY") and AbsGtk then
       mode = 'gtk'
    else
       mode = 'curses'
@@ -439,4 +446,4 @@ end
 
 abstk.set_mode()
 
-return abstk
+return abstk

src/abstk/AbsCurses.lua

@@ -7,6 +7,17 @@
 -- @see abstk
 -------------------------------------------------
 
+local utf8
+
+if _VERSION < "Lua 5.3" then
+   local has_dep, utf8 = pcall(require, 'lua-utf8')
+   if not has_dep then
+      utf8 = { len = string.len }
+   end
+else
+   utf8 = require 'utf8'
+end
+
 local AbsCurses = {}
 
 local curses = require 'curses'

src/abstk/util.lua

@@ -8,6 +8,17 @@
 -- @see AbsGtk
 -------------------------------------------------
 
+local utf8
+
+if _VERSION < "Lua 5.3" then
+   local has_dep, utf8 = pcall(require, 'lua-utf8')
+   if not has_dep then
+      utf8 = { len = string.len }
+   end
+else
+   utf8 = require 'utf8'
+end
+
 local util = {}
 
 function util.make_list_items(make_item, list, default_value)
@@ -69,4 +80,4 @@ function util.debug(debug_message)
    file:close()
 end
 
-return util
+return util