modify dump() function to work better in repl

dump.lua

@@ -0,0 +1,124 @@
+-- Copied from luanti builins and modified.
+
+-- Modified output:
+-- 1. Name of player or luaentity for userdata
+-- 2. Invalid ObjectRefs
+-- 3. Output indices of "array" tables
+
+
+local keywords = {
+    ["and"] = true,
+    ["break"] = true,
+    ["do"] = true,
+    ["else"] = true,
+    ["elseif"] = true,
+    ["end"] = true,
+    ["false"] = true,
+    ["for"] = true,
+    ["function"] = true,
+    ["goto"] = true,  -- Lua 5.2
+    ["if"] = true,
+    ["in"] = true,
+    ["local"] = true,
+    ["nil"] = true,
+    ["not"] = true,
+    ["or"] = true,
+    ["repeat"] = true,
+    ["return"] = true,
+    ["then"] = true,
+    ["true"] = true,
+    ["until"] = true,
+    ["while"] = true,
+}
+local function is_valid_identifier(str)
+    if not str:find("^[a-zA-Z_][a-zA-Z0-9_]*$") or keywords[str] then
+        return false
+    end
+    return true
+end
+
+
+
+local function basic_dump(o)
+    local tp = type(o)
+    if tp == "number" then
+        return tostring(o)
+    elseif tp == "string" then
+        return string.format("%q", o)
+    elseif tp == "boolean" then
+        return tostring(o)
+    elseif tp == "nil" then
+        return "nil"
+	-- Uncomment for full function dumping support.
+	-- Not currently enabled because bytecode isn't very human-readable and
+	-- dump's output is intended for humans.
+	--elseif tp == "function" then
+	--	return string.format("loadstring(%q)", string.dump(o))
+    elseif tp == "userdata" then
+        if o:is_valid() then
+            if o.is_player then
+                if o:is_player() then
+                    return string.format('#<player: "%s">', o:get_player_name())
+                else
+                    local e = o:get_luaentity()
+                    if e then
+                        return string.format('#<luaentity: "%s">', e.name)
+                    else
+                        return string.format('#<ObjectRef: %s>', o)
+                    end
+                end
+            else
+                return tostring(o)
+            end
+        else
+            return string.format('#<invalid_ref: %s>', o)
+        end
+    else
+        return string.format("#<%s>", tp)
+    end
+end
+
+
+local function repl_dump(o, indent, nested, level)
+    local t = type(o)
+    if t ~= "table" then
+        return basic_dump(o)
+    end
+
+    -- Contains table -> true/nil of currently nested tables
+    nested = nested or {}
+    if nested[o] then
+        return "<circular reference>"
+    end
+    nested[o] = true
+    indent = indent or "\t"
+    level = level or 1
+
+    local ret = {}
+    local dumped_indexes = {}
+    for i, v in ipairs(o) do
+        ret[#ret + 1] = string.format("[%s] = %s", i, repl_dump(v, indent, nested, level + 1))
+        dumped_indexes[i] = true
+    end
+    for k, v in pairs(o) do
+        if not dumped_indexes[k] then
+            if type(k) ~= "string" or not is_valid_identifier(k) then
+                k = "["..repl_dump(k, indent, nested, level + 1).."]"
+            end
+            v = repl_dump(v, indent, nested, level + 1)
+            ret[#ret + 1] = k.." = "..v
+        end
+    end
+    nested[o] = nil
+    if indent ~= "" then
+        local indent_str = "\n"..string.rep(indent, level)
+        local end_indent_str = "\n"..string.rep(indent, level - 1)
+        return string.format("{%s%s%s}",
+                             indent_str,
+                             table.concat(ret, ","..indent_str),
+                             end_indent_str)
+    end
+    return "{"..table.concat(ret, ", ").."}"
+end
+
+return repl_dump

init.lua

@@ -2,6 +2,7 @@ local MODNAME = core.get_current_modname()
 local MODPATH = core.get_modpath(MODNAME)
 
 local util = dofile(MODPATH .. DIR_DELIM .. "util.lua")
+local repl_dump = dofile(MODPATH .. DIR_DELIM .. "dump.lua")
 
 local api = {}
 _G[MODNAME] = api
@@ -145,7 +146,7 @@ core.register_chatcommand("eval",
                     -- returned single value or error
                     env._ = res[2]
                     if ok then
-                        return dump(res[2])
+                        return repl_dump(res[2])
                     else
                         -- combine returned error and stack trace
                         return string.format("%s\n%s", res[2], debug.traceback(coro))
@@ -155,7 +156,7 @@ core.register_chatcommand("eval",
                     env._ = res[2]
                     local ret_vals = {}
                     for i=2, n do
-                        table.insert(ret_vals, dump(res[i]))
+                        table.insert(ret_vals, repl_dump(res[i]))
                     end
                     return table.concat(ret_vals, ',\n')
                 end