From 4ad4a77b3da1f04fa6ce5421d843e2da57a8f4ea Mon Sep 17 00:00:00 2001
From: Jo-Philipp Wich <jow@openwrt.org>
Date: Sun, 8 Jun 2008 20:51:48 +0000
Subject: [PATCH] * luci/core:    add spairs(), kspairs() and vspairs() sorted
 hashtable iterator functions

---
 libs/core/luasrc/util.lua | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/libs/core/luasrc/util.lua b/libs/core/luasrc/util.lua
index 11f77206b..ad53138e6 100644
--- a/libs/core/luasrc/util.lua
+++ b/libs/core/luasrc/util.lua
@@ -318,3 +318,40 @@ function parse_units(ustr)
 
 	return val
 end
+
+
+-- Provide various sorting iterators
+function _sortiter( t, f )
+	local keys = { }
+
+	for k, v in pairs(t) do
+		table.insert( keys, k )
+	end
+
+	local _pos = 0
+	local _len = table.getn( keys )
+
+	table.sort( keys, f )
+
+	return function()
+		_pos = _pos + 1
+		if _pos <= _len then
+			return keys[_pos], t[keys[_pos]]
+		end
+	end
+end
+
+-- Return key, value pairs sorted by provided callback function
+function spairs(t,f)
+	return _sortiter( t, f )					
+end
+
+-- Return key, value pairs sorted by keys
+function kspairs(t)
+	return _sortiter( t )
+end
+
+-- Return key, value pairs sorted by values
+function vspairs(t)
+	return _sortiter( t, function (a,b) return t[a] < t[b] end )
+end
-- 
2.11.0