Backport several ROM/Lua commits

- Fix GPS returning nan on duplicate positions.
 - Distinguish between all parsers passing and failing.
 - Improve several comma related parse errors.
 - Ignore metatables in textutils.serialize.
 - Detect common audio containers in "speaker".

Co-authored-by: Wojbie <Wojbie@gmail.com>

src/main/resources/data/computercraft/lua/rom/apis/gps.lua

@@ -153,12 +153,22 @@ function locate(_nTimeout, _bDebug)
                     if tFix.nDistance == 0 then
                         pos1, pos2 = tFix.vPosition, nil
                     else
-                        table.insert(tFixes, tFix)
+                        -- Insert our new position in our table, with a maximum of three items. If this is close to a
+                        -- previous position, replace that instead of inserting.
+                        local insIndex = math.min(3, #tFixes + 1)
+                        for i, older in pairs(tFixes) do
+                            if (older.vPosition - tFix.vPosition):length() < 1 then
+                                insIndex = i
+                                break
+                            end
+                        end
+                        tFixes[insIndex] = tFix
+
                         if #tFixes >= 3 then
                             if not pos1 then
-                                pos1, pos2 = trilaterate(tFixes[1], tFixes[2], tFixes[#tFixes])
+                                pos1, pos2 = trilaterate(tFixes[1], tFixes[2], tFixes[3])
                             else
-                                pos1, pos2 = narrow(pos1, pos2, tFixes[#tFixes])
+                                pos1, pos2 = narrow(pos1, pos2, tFixes[3])
                             end
                         end
                     end

src/main/resources/data/computercraft/lua/rom/apis/settings.lua

@@ -74,8 +74,7 @@ function undefine(name)
     details[name] = nil
 end
 
-local function set_value(name, value)
-    local new = reserialize(value)
+local function set_value(name, new)
     local old = values[name]
     if old == nil then
         local opt = details[name]
@@ -103,7 +102,7 @@ function set(name, value)
     local opt = details[name]
     if opt and opt.type then expect(2, value, opt.type) end
 
-    set_value(name, value)
+    set_value(name, reserialize(value))
 end
 
 --- Get the value of a setting.
@@ -214,7 +213,9 @@ function load(sPath)
         if type(k) == "string" and (ty_v == "string" or ty_v == "number" or ty_v == "boolean" or ty_v == "table") then
             local opt = details[k]
             if not opt or not opt.type or ty_v == opt.type then
-                set_value(k, v)
+                -- This may fail if the table is recursive (or otherwise cannot be serialized).
+                local ok, v = pcall(reserialize, v)
+                if ok then set_value(k, v) end
             end
         end
     end

src/main/resources/data/computercraft/lua/rom/apis/textutils.lua

@@ -292,6 +292,13 @@ local g_tLuaKeywords = {
     ["while"] = true,
 }
 
+--- A version of the ipairs iterator which ignores metamethods
+local function inext(tbl, i)
+    i = (i or 0) + 1
+    local v = rawget(tbl, i)
+    if v == nil then return nil else return i, v end
+end
+
 local serialize_infinity = math.huge
 local function serialize_impl(t, tracking, indent, opts)
     local sType = type(t)
@@ -318,11 +325,11 @@ local function serialize_impl(t, tracking, indent, opts)
 
             result = open
             local seen_keys = {}
-            for k, v in ipairs(t) do
+            for k, v in inext, t do
                 seen_keys[k] = true
                 result = result .. sub_indent .. serialize_impl(v, tracking, sub_indent, opts) .. comma
             end
-            for k, v in pairs(t) do
+            for k, v in next, t do
                 if not seen_keys[k] then
                     local sEntry
                     if type(k) == "string" and not g_tLuaKeywords[k] and string.match(k, "^[%a_][%a%d_]*$") then

src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/errors.lua

@@ -364,6 +364,48 @@ function errors.table_key_equals(start_pos, end_pos)
     }
 end
 
+--[[- There is a trailing comma in this list of function arguments.
+
+@tparam number token The token id.
+@tparam number token_start The start position of the token.
+@tparam number token_end The end position of the token.
+@tparam number prev The start position of the previous entry.
+@treturn table The resulting parse error.
+]]
+function errors.missing_table_comma(token, token_start, token_end, prev)
+    expect(1, token, "number")
+    expect(2, token_start, "number")
+    expect(3, token_end, "number")
+    expect(4, prev, "number")
+
+    return {
+        "Unexpected " .. token_names[token] .. " in table.",
+        annotate(token_start, token_end),
+        annotate(prev + 1, prev + 1, "Are you missing a comma here?"),
+    }
+end
+
+--[[- There is a trailing comma in this list of function arguments.
+
+@tparam number comma_start The start position of the `,` token.
+@tparam number comma_end The end position of the `,` token.
+@tparam number paren_start The start position of the `)` token.
+@tparam number paren_end The end position of the `)` token.
+@treturn table The resulting parse error.
+]]
+function errors.trailing_call_comma(comma_start, comma_end, paren_start, paren_end)
+    expect(1, comma_start, "number")
+    expect(2, comma_end, "number")
+    expect(3, paren_start, "number")
+    expect(4, paren_end, "number")
+
+    return {
+        "Unexpected " .. code(")") .. " in function call.",
+        annotate(paren_start, paren_end),
+        annotate(comma_start, comma_end, "Tip: Try removing this " .. code(",") .. "."),
+    }
+end
+
 --------------------------------------------------------------------------------
 -- Statement parsing errors
 --------------------------------------------------------------------------------

src/main/resources/data/computercraft/lua/rom/programs/fun/speaker.lua

@@ -26,6 +26,12 @@ local function pcm_decoder(chunk)
     return buffer
 end
 
+local function report_invalid_format(format)
+    printError(("The speaker cannot play %s files."):format(format))
+    local pp = require "cc.pretty"
+    pp.print("Run '" .. pp.text("help speaker", colours.lightGrey) .. "' for information on supported formats.")
+end
+
 
 local cmd = ...
 if cmd == "stop" then
@@ -93,6 +99,10 @@ elseif cmd == "play" then
 
         handle.read(4)
         start = nil
+    -- Detect several other common audio files.
+    elseif start == "OggS" then return report_invalid_format("Ogg")
+    elseif start == "fLaC" then return report_invalid_format("FLAC")
+    elseif start:sub(1, 3) == "ID3" then return report_invalid_format("MP3")
     end
 
     print("Playing " .. file)