add replace method

benches/query.luau

@@ -8,7 +8,7 @@ local function TITLE(title: string)
 	print(testkit.color.white(title))
 end
 
-local jecs = require("../lib/init")
+local jecs = require("@jecs")
 local mirror = require("../mirror/init")
 
 type i53 = number

src/init.luau

@@ -662,16 +662,24 @@ local function noop(_self: Query, ...): () -> ()
 end
 
 local EmptyQuery = {
-	__iter = noop,
-	without = noop,
+	__iter = iterNoop,
+	next = noop,
+	replace = noop,
+	without = function()
+		return EmptyQuery
+	end
 }
-EmptyQuery.__index = EmptyQuery
-setmetatable(EmptyQuery, EmptyQuery)
 
 export type Query = typeof(EmptyQuery)
 
 type CompatibleArchetype = { archetype: Archetype, indices: { number } }
 
+local function replaceColumns(row, columns, ...)
+	for i, column in columns do
+		column[row] = select(i, ...)
+	end
+end
+
 local function preparedQuery(compatibleArchetypes: { Archetype },
 	components: { i53? }, indices: { { number } })
 
@@ -783,20 +791,64 @@ local function preparedQuery(compatibleArchetypes: { Archetype },
 		return self
 	end
 
-	local it = {
-		__iter = function() 
-			lastArchetype = 1
-			archetype = compatibleArchetypes[1]
-			entities = archetype.entities
-			i = #entities
+	local function iter()
+        lastArchetype = 1
+		archetype = compatibleArchetypes[1]
+		entities = archetype.entities
+		i = #entities
 
-			return queryNext
-		end,
+		return queryNext
+	end
+
+	local function replace()
+        for _, compatibleArchetype in compatibleArchetypes do
+			local archetype = compatibleArchetype.archetype
+			local tr = compatibleArchetype.indices
+			local columns = archetype.columns
+
+			for row in archetype.entities do
+				if queryLength == 1 then
+					local a = columns[tr[1]]
+					local pa = fn(a[row])
+
+					a[row] = pa
+				elseif queryLength == 2 then
+					local a = columns[tr[1]]
+					local b = columns[tr[2]]
+
+					a[row], b[row] = fn(a[row], b[row])
+				elseif queryLength == 3 then
+					local a = columns[tr[1]]
+					local b = columns[tr[2]]
+					local c = columns[tr[3]]
+
+					a[row], b[row], c[row] = fn(a[row], b[row], c[row])
+				elseif queryLength == 4 then
+					local a = columns[tr[1]]
+					local b = columns[tr[2]]
+					local c = columns[tr[3]]
+					local d = columns[tr[4]]
+
+					a[row], b[row], c[row], d[row] = fn(
+						a[row], b[row], c[row], d[row])
+				else
+					for i = 1, queryLength do
+						queryOutput[i] = columns[tr[i]][row]
+					end
+					replace(row, columns, fn(unpack(queryOutput)))
+				end
+			end
+		end
+	end
+
+	local it = {
+		__iter = iter,
 		next = queryNext,
-		without = without
+		without = without,
+		replace = replace
 	}
 
-	return setmetatable(it, it) :: any
+	return it
 end
 
 local function query(world: World, ...: number): Query