Rework Event-handling Mechanism (#351)

Author: harrysolovay

.changeset/heavy-ravens-vanish.md

@@ -0,0 +1,5 @@
+---
+"liminal": minor
+---
+
+Introduce L.handle / rework strand event-handling mechanism.

.github/workflows/liminal.land.yml

@@ -13,7 +13,7 @@ concurrency:
 jobs:
   build:
     runs-on: ubuntu-latest
-    timeout-minutes: 1
+    timeout-minutes: 2
     steps:
       - uses: actions/checkout@v4
       - uses: oven-sh/setup-bun@v1
@@ -28,7 +28,7 @@ jobs:
           path: liminal.land/.vitepress/dist
   deploy:
     runs-on: ubuntu-latest
-    timeout-minutes: 1
+    timeout-minutes: 2
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}

README.md

@@ -21,29 +21,42 @@ An effect is a conversation.
 
 ```ts
 import { FileSystem } from "@effect/platform"
-import { Console, Effect } from "effect"
+import { Effect } from "effect"
 import { L } from "liminal"
 
 const conversation = Effect.gen(function*() {
-  // Set system.
+  // Set system instruction.
   yield* L.system`You are an expert TypeScript developer.`
 
+  // Get a file system service.
+  const fs = yield* FileSystem.FileSystem
+
   // Append messages.
   yield* L.user`
     It seems as though a new mental model may arise for
     LLM conversation state management.
 
     What are your thoughts on the following DX?
+
+    ${fs.readFileString("example.ts")}
   `
-  const fs = yield* FileSystem.FileSystem
-  const code = yield* fs.readFileString("example.ts")
-  yield* L.user(code)
 
   // Infer and append the assistant message.
-  const reply = yield* L.assistant
+  const answer = yield* L.assistant
+
+  answer satisfies string
+
+  // List all messages.
+  const messages = yield* L.messages
+
+  // Clear all messages.
+  yield* L.clear
 
-  reply satisfies string
-}).pipe(L.strand)
+  // Re-append messages.
+  yield* L.append(...messages)
+}).pipe(
+  L.strand,
+)
 ```
 
 ## Running Examples Locally

bun.lock

@@ -1,13 +1,8 @@
-import { Console, Effect, flow, Stream } from "effect"
+import { Console, Effect, flow } from "effect"
 import { L, LPretty } from "liminal"
 
-export const logger = L.events.pipe(
-  Stream.runForEach(
-    flow(
-      LPretty.event,
-      Console.log,
-      Effect.andThen(Console.log()),
-    ),
-  ),
-  Effect.fork,
-)
+export const logger = L.handle(flow(
+  LPretty.event,
+  Console.log,
+  Effect.andThen(Console.log()),
+))

examples/_logger.ts

@@ -24,6 +24,7 @@ Effect.gen(function*() {
   }
 }).pipe(
   L.strand,
+  Effect.scoped,
   Effect.provide(ModelLive),
   Effect.runFork,
 )

examples/activity_suggestions.ts

@@ -0,0 +1,15 @@
+import { Effect } from "effect"
+import { L } from "liminal"
+import { ModelLive } from "./_layers.ts"
+import { logger } from "./_logger.ts"
+
+Effect.gen(function*() {
+  yield* logger
+  yield* L.user`Hey`
+  yield* L.assistant
+}).pipe(
+  L.strand,
+  Effect.scoped,
+  Effect.provide(ModelLive),
+  Effect.runFork,
+)

examples/basic.ts

@@ -5,6 +5,7 @@ import { logger } from "./_logger.ts"
 
 Effect.gen(function*() {
   yield* logger
+
   yield* L.system`Write persuasive marketing copy for: Buffy The Vampire Slayer.`
   yield* L.user`Please generate the first draft.`
   let copy = yield* L.assistant
@@ -37,6 +38,7 @@ Effect.gen(function*() {
   return { copy, qualityMetrics }
 }).pipe(
   L.strand,
+  Effect.scoped,
   Effect.provide(ModelLive),
   Effect.runFork,
 )

examples/chaining.ts

@@ -32,6 +32,7 @@ Effect.gen(function*() {
   return variants[key]
 }).pipe(
   L.strand,
+  Effect.scoped,
   Effect.provide([ModelLive, ClientLive]),
   Effect.runFork,
 )

examples/compare_models.ts

@@ -67,6 +67,7 @@ Effect.gen(function*() {
   }
 }).pipe(
   L.strand,
+  Effect.scoped,
   Effect.provide([ModelLive, BunContext.layer]),
   Effect.runFork,
 )