Data commit

Task/Optional-parameters/Lua/optional-parameters.lua

@@ -0,0 +1,43 @@
+function showTable(tbl)
+	if type(tbl)=='table' then
+		local result = {}
+		for _, val in pairs(tbl) do
+			table.insert(result, showTable(val))
+		end
+		return '{' .. table.concat(result, ', ') .. '}'
+	else
+		return (tostring(tbl))
+	end
+end
+
+function sortTable(op)
+	local tbl = op.table or {}
+	local column = op.column or 1
+	local reverse = op.reverse or false
+	local cmp = op.cmp or (function (a, b) return a < b end)
+	local compareTables = function (a, b)
+		local result = cmp(a[column], b[column])
+		if reverse then return not result else return result end
+	end
+	table.sort(tbl, compareTables)
+end
+
+A = {{"quail", "deer", "snake"},
+	{"dalmation", "bear", "fox"},
+	{"ant", "cougar", "coyote"}}
+print('original', showTable(A))
+
+sortTable{table=A}
+print('defaults', showTable(A))
+
+sortTable{table=A, column=2}
+print('col 2    ', showTable(A))
+
+sortTable{table=A, column=3}
+print('col 3    ', showTable(A))
+
+sortTable{table=A, column=3, reverse=true}
+print('col 3 rev', showTable(A))
+
+sortTable{table=A, cmp=(function (a, b) return #a < #b end)}
+print('by length', showTable(A))