From 199b8ded1d752c5f6b29619eaf3843eca9c760ea Mon Sep 17 00:00:00 2001
From: jalhund <denismakhortovdev@gmail.com>
Date: Wed, 18 May 2022 05:17:31 +0000
Subject: [PATCH] tablex: Add spairs (alternative of pairs that returns sorted
 table)

---
 .test/tests.lua | 36 ++++++++++++++++++++++++++++++++++++
 tablex.lua      | 24 ++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/.test/tests.lua b/.test/tests.lua
index 260dda1..a8cd0c3 100644
--- a/.test/tests.lua
+++ b/.test/tests.lua
@@ -116,3 +116,39 @@ local function test_deep_equal()
 	assert(not tablex.deep_equal(y, x))
 end
 
+local function test_spairs()
+	local t = {
+		player1 = {
+			name = "Joe",
+			score = 8
+		},
+		player2 = {
+			name = "Robert",
+			score = 7
+		},
+		player3 = {
+			name = "John",
+			score = 10
+		}
+	}
+	
+	local sorted_names = {}
+	local sorted_score = {}
+	
+	for k, v in tablex.spairs(t, function(t, a, b)
+		return t[a].score > t[b].score
+	end) do
+		tablex.push(sorted_names, v.name)
+		tablex.push(sorted_score, v.score)
+	end
+	
+	assert(tablex.deep_equal(sorted_names,
+	{
+		"John", "Joe", "Robert"
+	}))
+	
+	assert(tablex.deep_equal(sorted_score,
+	{
+		10, 8, 7
+	}))
+end
\ No newline at end of file
diff --git a/tablex.lua b/tablex.lua
index 72cd437..8624dfb 100644
--- a/tablex.lua
+++ b/tablex.lua
@@ -537,4 +537,28 @@ function tablex.ripairs(t)
 	return _ripairs_iter, t, #t + 1
 end
 
+-- works like pairs, but returns sorted table
+function tablex.spairs(t, fn)
+	local keys = {}
+	for k in pairs(t) do
+		tablex.push(keys, k)
+	end
+
+	if fn then
+		table.sort(keys, function(a,b) return fn(t, a, b) end)
+	else
+		-- sort by keys if no function passed
+		table.sort(keys)
+	end
+
+	local i = 0
+	return function()
+		i = i + 1
+		if keys[i] then
+			return keys[i], t[keys[i]]
+		end
+	end
+end
+
+
 return tablex