improve to select script

scripts/packages.lua

@@ -1,59 +1,19 @@
 -- imports
 import("core.package.package")
 import("core.platform.platform")
+import("private.core.base.select_script")
 
 -- is supported platform and architecture?
 function is_supported(instance, plat, arch, opt)
 
     -- ignore template package
-    if instance.is_template and instance:is_template() then
+    if instance:is_template() then
         return false
     end
 
     -- get script
     local script = instance:get("install")
-    local result = nil
-    if type(script) == "function" then
-        result = script
-    elseif type(script) == "table" then
-
-        -- get plat and arch
-        local plat = plat or ""
-        local arch = arch or ""
-
-        -- match pattern
-        --
-        -- `@linux`
-        -- `@linux|x86_64`
-        -- `@macosx,linux`
-        -- `android@macosx,linux`
-        -- `android|armeabi-v7a@macosx,linux`
-        -- `android|armeabi-v7a@macosx,linux|x86_64`
-        -- `android|armeabi-v7a@linux|x86_64`
-        --
-        for _pattern, _script in pairs(script) do
-            local hosts = {}
-            local hosts_spec = false
-            _pattern = _pattern:gsub("@(.+)", function (v)
-                for _, host in ipairs(v:split(',')) do
-                    hosts[host] = true
-                    hosts_spec = true
-                end
-                return ""
-            end)
-            if _pattern:trim() == "" and opt and opt.onlyhost then
-                _pattern = os.subhost()
-            end
-            if not _pattern:startswith("__") and (not hosts_spec or hosts[os.subhost() .. '|' .. os.subarch()] or hosts[os.subhost()])
-            and (_pattern:trim() == "" or (plat .. '|' .. arch):find('^' .. _pattern .. '$') or plat:find('^' .. _pattern .. '$')) then
-                result = _script
-                break
-            end
-        end
-
-        -- get generic script
-        result = result or script["__generic__"]
-    end
+    local result = select_script(script, {plat = plat, arch = arch})
     return result
 end