2016 Update

Task/Multisplit/Lua/multisplit.lua

@@ -0,0 +1,53 @@
+--[[
+Returns a table of substrings by splitting the given string on
+occurrences of the given character delimiters, which may be specified
+as a single- or multi-character string or a table of such strings.
+If chars is omitted, it defaults to the set of all space characters,
+and keep is taken to be false. The limit and keep arguments are
+optional: they are a maximum size for the result and a flag
+determining whether empty fields should be kept in the result.
+]]
+function split (str, chars, limit, keep)
+    local limit, splitTable, entry, pos, match = limit or 0, {}, "", 1
+    if keep == nil then keep = true end
+    if not chars then
+        for e in string.gmatch(str, "%S+") do
+                table.insert(splitTable, e)
+        end
+        return splitTable
+    end
+    while pos <= str:len() do
+        match = nil
+        if type(chars) == "table" then
+            for _, delim in pairs(chars) do
+                if str:sub(pos, pos + delim:len() - 1) == delim then
+                    match = string.len(delim) - 1
+                    break
+                end
+            end
+        elseif str:sub(pos, pos + chars:len() - 1) == chars then
+            match = string.len(chars) - 1
+        end
+        if match then
+            if not (keep == false and entry == "") then
+                table.insert(splitTable, entry)
+                if #splitTable == limit then return splitTable end
+                entry = ""
+            end
+        else
+            entry = entry .. str:sub(pos, pos)
+        end
+        pos = pos + 1 + (match or 0)
+    end
+    if entry ~= "" then table.insert(splitTable, entry) end
+    return splitTable
+end
+
+local multisplit = split("a!===b=!=c", {"==", "!=", "="})
+
+-- Returned result is a table (key/value pairs) - display all entries
+print("Key\tValue")
+print("---\t-----")
+for k, v in pairs(multisplit) do
+    print(k, v)
+end