refactor query into yielding api

common/utils.ts

@@ -257,7 +257,7 @@ export function wait(ms: number) {
 }
 
 export async function run(cmd: string, ...args: string[]) {
-	const command = new Deno.Command(cmd, { args, stdout: "piped" });
+	const command = new Deno.Command(cmd, { args, stdin: "inherit", stdout: "piped" });
 	const output = await command.output();
 	if (!output.success) throw new Error();
 	return new TextDecoder().decode(output.stdout);

server/components/display.ts

@@ -1,6 +1,25 @@
+import { v2 } from "../../common/utils.ts";
+import { range, Vec2 } from "../../common/utils.ts";
+import { Engine } from "../engine.ts";
+import { query_in_rect } from "./world.ts";
+
 export class CompDisplay {
 	display;
 	constructor(display: string) {
 		this.display = display;
 	}
 }
+
+export function sys_render_world(center: Vec2, size: Vec2) {
+	return (engine: Engine) => {
+		const radius = size.scale(0.5);
+		const result = Array.from(range(0, size.y())).map(() => Array.from(range(0, size.x())).map(() => "  "));
+		const min = center.sub(radius);
+		const max = center.add(radius).sub(v2(1, 1));
+		for (const [pos, display] of engine.query_all(query_in_rect(min, max).with(CompDisplay))) {
+			const local_pos = pos.position.sub(min);
+			result[local_pos.y()][local_pos.x()] = display.display;
+		}
+		return result.map((line) => line.join("")).toReversed().join("\n");
+	};
+}

server/components/world.ts

@@ -61,11 +61,11 @@ Deno.test("test_displacement", () => {
 });
 
 export function query_at(pos: Vec2) {
-	return Query.filter(CompPos, (c) => c.position.overlaps(pos));
+	return Query.with(CompPos).filter(([c]) => c.position.overlaps(pos));
 }
 
 export function query_in_rect(min: Vec2, max: Vec2) {
-	return Query.filter(CompPos, (c) => c.position.inside(min, max));
+	return Query.with(CompPos).filter(([c]) => c.position.inside(min, max));
 }
 
 class CompStructure {}

server/engine.ts

@@ -60,11 +60,11 @@ export class Engine {
 		}
 	}
 
-	*query_all(query: Query) {
+	*query_all<O extends QueryRes>(query: Query<O>) {
 		yield* query.run(this.entities.values());
 	}
 
-	query_one(query: Query) {
+	query_one<O extends QueryRes>(query: Query<O>) {
 		return first(this.query_all(query));
 	}
 
@@ -85,41 +85,52 @@ export class Engine {
 	}
 }
 
-export class Query {
-	private test;
+type QueryRes<T = unknown> = readonly T[];
+export class Query<O extends QueryRes> {
+	extractor;
 
-	constructor(test: (entity: Entity) => boolean) {
-		this.test = test;
-	}
-
-	and(query: Query) {
-		return new Query((entity) => this.test(entity) && query.test(entity));
-	}
-
-	static with(...components: Constructible[]) {
-		return new Query((entity) => {
-			for (const comp of components) if (!entity.components.has(comp)) return false;
-			return true;
-		});
-	}
-
-	with(...components: Constructible[]) {
-		return this.and(Query.with(...components));
-	}
-
-	static filter<I>(component: Constructible<I>, filter: (comp: I, entity: Entity) => boolean) {
-		return new Query((entity) => {
-			const comp = entity.get(component);
-			if (comp === null) return false;
-			return filter(comp, entity);
-		});
-	}
-
-	filter<I>(component: Constructible<I>, filter: (comp: I, entity: Entity) => boolean) {
-		return this.and(Query.filter(component, filter));
+	constructor(extractor: (entity: Entity) => O | null) {
+		this.extractor = extractor;
 	}
 
 	*run(entities: Iterable<Entity>) {
-		for (const entity of entities) if (this.test(entity)) yield entity;
+		for (const entity of entities) {
+			const extracted = this.extractor(entity);
+			if (extracted !== null) yield extracted;
+		}
+	}
+
+	and<Q extends QueryRes>(other: Query<Q>) {
+		const this_extractor = this.extractor;
+		return new Query((entity) => {
+			const this_extracted = this_extractor(entity);
+			if (this_extracted === null) return null;
+			const other_extracted = other.extractor(entity);
+			if (other_extracted === null) return null;
+			return [...this_extracted, ...other_extracted] as const;
+		});
+	}
+
+	static with<I>(comp: Constructible<I>) {
+		function extract(entity: Entity) {
+			const extracted = entity.get(comp);
+			if (extracted === null) return null;
+			return [extracted] as const;
+		}
+		return new Query(extract);
+	}
+
+	with<I>(comp: Constructible<I>) {
+		return this.and(Query.with(comp));
+	}
+
+	filter(predicate: (comps: O) => boolean) {
+		const this_extract = this.extractor;
+		return new Query((entity) => {
+			const extracted = this_extract(entity);
+			if (extracted === null) return null;
+			if (predicate(extracted)) return extracted;
+			else return null;
+		});
 	}
 }

server/entities/player.ts

@@ -1,7 +1,7 @@
 import { mts } from "../../common/mod.ts";
-import { log_from, range, v2, Vec2 } from "../../common/utils.ts";
-import { CompDisplay } from "../components/display.ts";
-import { CompPos, query_in_rect, sys_find_free_pos } from "../components/world.ts";
+import { log_from, v2, Vec2 } from "../../common/utils.ts";
+import { CompDisplay, sys_render_world } from "../components/display.ts";
+import { CompPos, sys_find_free_pos } from "../components/world.ts";
 import { Engine, Entity } from "../engine.ts";
 import { ClientInterface } from "../network.ts";
 const log = log_from(import.meta);
@@ -58,20 +58,6 @@ export class Session {
 	}
 }
 
-export function sys_render_world(center: Vec2, size: Vec2) {
-	return (engine: Engine) => {
-		const radius = size.scale(0.5);
-		const result = Array.from(range(0, size.y())).map(() => Array.from(range(0, size.x())).map(() => "  "));
-		const min = center.sub(radius);
-		const max = center.add(radius);
-		for (const entity of engine.query_all(query_in_rect(min, max).with(CompDisplay))) {
-			const local_pos = entity.get_force(CompPos).position.sub(min);
-			result[local_pos.y()][local_pos.x()] = entity.get_force(CompDisplay).display;
-		}
-		return result.map((line) => line.join("")).toReversed().join("\n");
-	};
-}
-
 export function sys_spawn_player(position: Vec2) {
 	return (engine: Engine) => {
 		return engine.spawn((entity) =>