feat: add await syntax for direct async function calls and new generator/phonebook apps

Add compiler support for calling async functions directly with `await fn(args)` syntax, automatically translating to `await fn.call(args)`. Introduce `create_merge` Makefile target for merging Wren source files. Include new `apps/generator.wren` source code generator using OpenRouter API, `apps/phonebook.wren` CLI phonebook with SQLite backend, and `apps/minitut.md` Wren tutorial reference. Update `example/await_demo.wren` with parameterized async functions, nested awaits, and expression usage. Fix JSON parsing in `example/openrouter_demo.wren` to strip markdown code fences. Document new await syntax in `manual/api/scheduler.html`.

src/module/http.wren

@@ -137,18 +137,21 @@ class Http {
     requestHeaders["User-Agent"] = "Wren-CLI/1.0"
 
     if (bodyStr.count > 0) {
-      requestHeaders["Content-Length"] = bodyStr.count.toString
+      requestHeaders["Content-Length"] = bodyStr.bytes.count.toString
     }
 
     for (entry in headers) {
       requestHeaders[entry.key] = entry.value
     }
 
-    var request = "%(method) %(parsed.fullPath) HTTP/1.1\r\n"
+    var parts = []
+    parts.add("%(method) %(parsed.fullPath) HTTP/1.1\r\n")
     for (entry in requestHeaders) {
-      request = request + "%(entry.key): %(entry.value)\r\n"
+      parts.add("%(entry.key): %(entry.value)\r\n")
     }
-    request = request + "\r\n" + bodyStr
+    parts.add("\r\n")
+    parts.add(bodyStr)
+    var request = parts.join("")
 
     var addresses = Dns.lookup(parsed.host, 4)
     if (addresses.count == 0) {
@@ -163,12 +166,13 @@ class Http {
     }
     socket.write(request)
 
-    var response = ""
+    var chunks = []
     while (true) {
       var chunk = socket.read()
-      if (chunk == null || chunk.count == 0) break
-      response = response + chunk
+      if (chunk == null || chunk.bytes.count == 0) break
+      chunks.add(chunk)
     }
+    var response = chunks.join("")
     socket.close()
 
     return parseResponse_(response)
@@ -251,7 +255,7 @@ class Http {
   }
 
   static decodeChunked_(body) {
-    var result = ""
+    var parts = []
     var pos = 0
 
     while (pos < body.count) {
@@ -266,11 +270,11 @@ class Http {
       pos = lineEnd + 2
       if (pos + size > body.count) break
 
-      result = result + body[pos...(pos + size)]
+      parts.add(body[pos...(pos + size)])
       pos = pos + size + 2
     }
 
-    return result
+    return parts.join("")
   }
 
   static parseHex_(str) {

src/module/http.wren.inc

@@ -141,18 +141,21 @@ static const char* httpModuleSource =
 "    requestHeaders[\"User-Agent\"] = \"Wren-CLI/1.0\"\n"
 "\n"
 "    if (bodyStr.count > 0) {\n"
-"      requestHeaders[\"Content-Length\"] = bodyStr.count.toString\n"
+"      requestHeaders[\"Content-Length\"] = bodyStr.bytes.count.toString\n"
 "    }\n"
 "\n"
 "    for (entry in headers) {\n"
 "      requestHeaders[entry.key] = entry.value\n"
 "    }\n"
 "\n"
-"    var request = \"%(method) %(parsed.fullPath) HTTP/1.1\\r\\n\"\n"
+"    var parts = []\n"
+"    parts.add(\"%(method) %(parsed.fullPath) HTTP/1.1\\r\\n\")\n"
 "    for (entry in requestHeaders) {\n"
-"      request = request + \"%(entry.key): %(entry.value)\\r\\n\"\n"
+"      parts.add(\"%(entry.key): %(entry.value)\\r\\n\")\n"
 "    }\n"
-"    request = request + \"\\r\\n\" + bodyStr\n"
+"    parts.add(\"\\r\\n\")\n"
+"    parts.add(bodyStr)\n"
+"    var request = parts.join(\"\")\n"
 "\n"
 "    var addresses = Dns.lookup(parsed.host, 4)\n"
 "    if (addresses.count == 0) {\n"
@@ -167,12 +170,13 @@ static const char* httpModuleSource =
 "    }\n"
 "    socket.write(request)\n"
 "\n"
-"    var response = \"\"\n"
+"    var chunks = []\n"
 "    while (true) {\n"
 "      var chunk = socket.read()\n"
-"      if (chunk == null || chunk.count == 0) break\n"
-"      response = response + chunk\n"
+"      if (chunk == null || chunk.bytes.count == 0) break\n"
+"      chunks.add(chunk)\n"
 "    }\n"
+"    var response = chunks.join(\"\")\n"
 "    socket.close()\n"
 "\n"
 "    return parseResponse_(response)\n"
@@ -255,7 +259,7 @@ static const char* httpModuleSource =
 "  }\n"
 "\n"
 "  static decodeChunked_(body) {\n"
-"    var result = \"\"\n"
+"    var parts = []\n"
 "    var pos = 0\n"
 "\n"
 "    while (pos < body.count) {\n"
@@ -270,11 +274,11 @@ static const char* httpModuleSource =
 "      pos = lineEnd + 2\n"
 "      if (pos + size > body.count) break\n"
 "\n"
-"      result = result + body[pos...(pos + size)]\n"
+"      parts.add(body[pos...(pos + size)])\n"
 "      pos = pos + size + 2\n"
 "    }\n"
 "\n"
-"    return result\n"
+"    return parts.join(\"\")\n"
 "  }\n"
 "\n"
 "  static parseHex_(str) {\n"

src/module/io.c

@@ -31,6 +31,9 @@ static WrenHandle* stdinOnData = NULL;
 // The stream used to read from stdin. Initialized on the first read.
 static uv_stream_t* stdinStream = NULL;
 
+// True if stdin is a file/device that doesn't support async I/O.
+static bool stdinIsFile = false;
+
 // True if stdin has been set to raw mode.
 static bool isStdinRaw = false;
 
@@ -514,11 +517,19 @@ static void initStdin()
     }
     else
     {
-      // stdin is a pipe or a file.
-      uv_pipe_t* handle = (uv_pipe_t*)malloc(sizeof(uv_pipe_t));
-      uv_pipe_init(getLoop(), handle, false);
-      uv_pipe_open(handle, stdinDescriptor);
-      stdinStream = (uv_stream_t*)handle;
+      uv_handle_type htype = uv_guess_handle(stdinDescriptor);
+      if (htype == UV_FILE || htype == UV_UNKNOWN_HANDLE)
+      {
+        stdinIsFile = true;
+        stdinStream = NULL;
+      }
+      else
+      {
+        uv_pipe_t* handle = (uv_pipe_t*)malloc(sizeof(uv_pipe_t));
+        uv_pipe_init(getLoop(), handle, false);
+        uv_pipe_open(handle, stdinDescriptor);
+        stdinStream = (uv_stream_t*)handle;
+      }
     }
   }
 }
@@ -577,53 +588,104 @@ static void stdinReadCallback(uv_stream_t* stream, ssize_t numRead,
                               const uv_buf_t* buffer)
 {
   WrenVM* vm = getVM();
-  
+
   if (stdinClass == NULL)
   {
     wrenEnsureSlots(vm, 1);
     wrenGetVariable(vm, "io", "Stdin", 0);
     stdinClass = wrenGetSlotHandle(vm, 0);
   }
-  
+
   if (stdinOnData == NULL)
   {
     stdinOnData = wrenMakeCallHandle(vm, "onData_(_)");
   }
-  
-  // If stdin was closed, send null to let io.wren know.
-  if (numRead == UV_EOF)
+
+  if (numRead < 0)
   {
+    if (numRead != UV_EOF)
+    {
+      uv_read_stop(stdinStream);
+      uv_stop(getLoop());
+      setExitCode(70);
+      return;
+    }
+
     wrenEnsureSlots(vm, 2);
     wrenSetSlotHandle(vm, 0, stdinClass);
     wrenSetSlotNull(vm, 1);
-    wrenCall(vm, stdinOnData);
-    
-    shutdownStdin();
+    WrenInterpretResult result = wrenCall(vm, stdinOnData);
+
+    if (result == WREN_RESULT_RUNTIME_ERROR)
+    {
+      uv_stop(getLoop());
+      setExitCode(70);
+    }
     return;
   }
 
-  // TODO: Handle other errors.
-
-  // TODO: Having to copy the bytes here is a drag. It would be good if Wren's
-  // embedding API supported a way to *give* it bytes that were previously
-  // allocated using Wren's own allocator.
   wrenEnsureSlots(vm, 2);
   wrenSetSlotHandle(vm, 0, stdinClass);
   wrenSetSlotBytes(vm, 1, buffer->base, numRead);
-  wrenCall(vm, stdinOnData);
+  WrenInterpretResult result = wrenCall(vm, stdinOnData);
 
-  // TODO: Likewise, freeing this after we resume is lame.
   free(buffer->base);
+
+  if (result == WREN_RESULT_RUNTIME_ERROR)
+  {
+    uv_stop(getLoop());
+    setExitCode(70);
+  }
+}
+
+static uv_timer_t stdinFileTimer;
+
+static void stdinFileTimerCallback(uv_timer_t* handle)
+{
+  WrenVM* vm = getVM();
+
+  if (stdinClass == NULL)
+  {
+    wrenEnsureSlots(vm, 1);
+    wrenGetVariable(vm, "io", "Stdin", 0);
+    stdinClass = wrenGetSlotHandle(vm, 0);
+  }
+
+  if (stdinOnData == NULL)
+  {
+    stdinOnData = wrenMakeCallHandle(vm, "onData_(_)");
+  }
+
+  wrenEnsureSlots(vm, 2);
+  wrenSetSlotHandle(vm, 0, stdinClass);
+  wrenSetSlotNull(vm, 1);
+  WrenInterpretResult result = wrenCall(vm, stdinOnData);
+
+  if (result == WREN_RESULT_RUNTIME_ERROR)
+  {
+    uv_stop(getLoop());
+    setExitCode(70);
+  }
 }
 
 void stdinReadStart(WrenVM* vm)
 {
   initStdin();
+
+  if (stdinIsFile)
+  {
+    uv_timer_init(getLoop(), &stdinFileTimer);
+    uv_timer_start(&stdinFileTimer, stdinFileTimerCallback, 0, 0);
+    return;
+  }
+
   uv_read_start(stdinStream, allocCallback, stdinReadCallback);
-  // TODO: Check return.
 }
 
 void stdinReadStop(WrenVM* vm)
 {
-  uv_read_stop(stdinStream);
+  if (stdinStream != NULL)
+  {
+    uv_read_stop(stdinStream);
+  }
 }

src/module/io.wren

@@ -280,6 +280,7 @@ class Stdin {
       } else {
         __waitingFiber.transferError("Stdin was closed.")
       }
+      return
     }
 
     // Append to the buffer.

src/module/io.wren.inc

@@ -284,6 +284,7 @@ static const char* ioModuleSource =
 "      } else {\n"
 "        __waitingFiber.transferError(\"Stdin was closed.\")\n"
 "      }\n"
+"      return\n"
 "    }\n"
 "\n"
 "    // Append to the buffer.\n"

src/module/repl.wren

@@ -1,6 +1,7 @@
 import "meta" for Meta
 import "io" for Stdin, Stdout
 import "os" for Platform
+import "scheduler" for Scheduler
 
 /// Abstract base class for the REPL. Manages the input line and history, but
 /// does not render.
@@ -65,7 +66,7 @@ class Repl {
       } else {
         // TODO: Handle ESC 0 sequences.
       }
-    } else if (byte == Chars.carriageReturn) {
+    } else if (byte == Chars.carriageReturn || byte == Chars.lineFeed) {
       executeInput()
     } else if (byte == Chars.delete) {
       deleteLeft()
@@ -197,8 +198,15 @@ class Repl {
     var fiber = Fiber.new(closure)
 
     var result = fiber.try()
+
+    while (!fiber.isDone && fiber.error == null && Scheduler.hasScheduled_) {
+      Scheduler.runNextScheduled_()
+      if (!fiber.isDone && fiber.error == null) {
+        result = fiber.try()
+      }
+    }
+
     if (fiber.error != null) {
-      // TODO: Include callstack.
       showRuntimeError("Runtime error: %(fiber.error)")
       return
     }

src/module/repl.wren.inc

@@ -5,6 +5,7 @@ static const char* replModuleSource =
 "import \"meta\" for Meta\n"
 "import \"io\" for Stdin, Stdout\n"
 "import \"os\" for Platform\n"
+"import \"scheduler\" for Scheduler\n"
 "\n"
 "/// Abstract base class for the REPL. Manages the input line and history, but\n"
 "/// does not render.\n"
@@ -69,7 +70,7 @@ static const char* replModuleSource =
 "      } else {\n"
 "        // TODO: Handle ESC 0 sequences.\n"
 "      }\n"
-"    } else if (byte == Chars.carriageReturn) {\n"
+"    } else if (byte == Chars.carriageReturn || byte == Chars.lineFeed) {\n"
 "      executeInput()\n"
 "    } else if (byte == Chars.delete) {\n"
 "      deleteLeft()\n"
@@ -201,8 +202,15 @@ static const char* replModuleSource =
 "    var fiber = Fiber.new(closure)\n"
 "\n"
 "    var result = fiber.try()\n"
+"\n"
+"    while (!fiber.isDone && fiber.error == null && Scheduler.hasScheduled_) {\n"
+"      Scheduler.runNextScheduled_()\n"
+"      if (!fiber.isDone && fiber.error == null) {\n"
+"        result = fiber.try()\n"
+"      }\n"
+"    }\n"
+"\n"
 "    if (fiber.error != null) {\n"
-"      // TODO: Include callstack.\n"
 "      showRuntimeError(\"Runtime error: %(fiber.error)\")\n"
 "      return\n"
 "    }\n"

src/module/scheduler.wren

@@ -40,6 +40,10 @@ class Scheduler {
     }
   }
 
+  static hasScheduled_ {
+    return __scheduled != null && !__scheduled.isEmpty
+  }
+
   foreign static captureMethods_()
 }
 
@@ -71,6 +75,8 @@ class Future {
 
   isDone { _resolved }
   result { _result }
+
+  call() { this }
 }
 
 Scheduler.captureMethods_()

src/module/scheduler.wren.inc

@@ -44,6 +44,10 @@ static const char* schedulerModuleSource =
 "    }\n"
 "  }\n"
 "\n"
+"  static hasScheduled_ {\n"
+"    return __scheduled != null && !__scheduled.isEmpty\n"
+"  }\n"
+"\n"
 "  foreign static captureMethods_()\n"
 "}\n"
 "\n"
@@ -75,6 +79,8 @@ static const char* schedulerModuleSource =
 "\n"
 "  isDone { _resolved }\n"
 "  result { _result }\n"
+"\n"
+"  call() { this }\n"
 "}\n"
 "\n"
 "Scheduler.captureMethods_()\n";

src/module/tls.c

@@ -336,14 +336,32 @@ void tlsSocketWrite(WrenVM* vm) {
     data->fiber = fiber;
     data->writeInProgress = true;
 
-    int written = SSL_write(data->ssl, text, length);
-    if (written <= 0) {
-        int err = SSL_get_error(data->ssl, written);
-        if (err != SSL_ERROR_WANT_READ && err != SSL_ERROR_WANT_WRITE) {
-            data->writeInProgress = false;
-            data->fiber = NULL;
-            schedulerResumeError(fiber, "SSL write error");
-            return;
+    int totalWritten = 0;
+    while (totalWritten < length) {
+        int written = SSL_write(data->ssl, text + totalWritten, length - totalWritten);
+        if (written > 0) {
+            totalWritten += written;
+        } else {
+            int err = SSL_get_error(data->ssl, written);
+            if (err == SSL_ERROR_WANT_WRITE) {
+                char buffer[16384];
+                int pending;
+                while ((pending = BIO_read(data->writeBio, buffer, sizeof(buffer))) > 0) {
+                    TlsWriteRequest* wr = (TlsWriteRequest*)malloc(sizeof(TlsWriteRequest));
+                    wr->buf.base = (char*)malloc(pending);
+                    wr->buf.len = pending;
+                    memcpy(wr->buf.base, buffer, pending);
+                    wr->data = data;
+                    wr->isLast = false;
+                    wr->req.data = wr;
+                    uv_write(&wr->req, (uv_stream_t*)data->handle, &wr->buf, 1, tlsWriteCallback);
+                }
+            } else if (err != SSL_ERROR_WANT_READ) {
+                data->writeInProgress = false;
+                data->fiber = NULL;
+                schedulerResumeError(fiber, "SSL write error");
+                return;
+            }
         }
     }
 

src/module/web.wren

@@ -431,7 +431,7 @@ class Application {
 
     while (true) {
       var chunk = socket.read()
-      if (chunk == null || chunk.count == 0) {
+      if (chunk == null || chunk.bytes.count == 0) {
         socket.close()
         return
       }
@@ -637,7 +637,7 @@ class Client {
     var response = ""
     while (true) {
       var chunk = socket.read()
-      if (chunk == null || chunk.count == 0) break
+      if (chunk == null || chunk.bytes.count == 0) break
       response = response + chunk
     }
     socket.close()

src/module/web.wren.inc

@@ -435,7 +435,7 @@ static const char* webModuleSource =
 "\n"
 "    while (true) {\n"
 "      var chunk = socket.read()\n"
-"      if (chunk == null || chunk.count == 0) {\n"
+"      if (chunk == null || chunk.bytes.count == 0) {\n"
 "        socket.close()\n"
 "        return\n"
 "      }\n"
@@ -641,7 +641,7 @@ static const char* webModuleSource =
 "    var response = \"\"\n"
 "    while (true) {\n"
 "      var chunk = socket.read()\n"
-"      if (chunk == null || chunk.count == 0) break\n"
+"      if (chunk == null || chunk.bytes.count == 0) break\n"
 "      response = response + chunk\n"
 "    }\n"
 "    socket.close()\n"

src/module/websocket.wren

@@ -112,7 +112,7 @@ class WebSocket {
     var response = ""
     while (true) {
       var chunk = socket.read()
-      if (chunk == null || chunk.count == 0) {
+      if (chunk == null || chunk.bytes.count == 0) {
         Fiber.abort("Connection closed during handshake")
       }
       response = response + chunk
@@ -428,7 +428,7 @@ class WebSocket {
   readBytes_(count) {
     while (Bytes.length(_readBuffer) < count) {
       var chunk = _socket.read()
-      if (chunk == null || chunk.count == 0) {
+      if (chunk == null || chunk.bytes.count == 0) {
         if (Bytes.length(_readBuffer) == 0) return null
         var result = _readBuffer
         _readBuffer = ""
@@ -469,7 +469,7 @@ class WebSocketServer {
     var request = ""
     while (true) {
       var chunk = socket.read()
-      if (chunk == null || chunk.count == 0) {
+      if (chunk == null || chunk.bytes.count == 0) {
         socket.close()
         return null
       }

src/module/websocket.wren.inc

@@ -116,7 +116,7 @@ static const char* websocketModuleSource =
 "    var response = \"\"\n"
 "    while (true) {\n"
 "      var chunk = socket.read()\n"
-"      if (chunk == null || chunk.count == 0) {\n"
+"      if (chunk == null || chunk.bytes.count == 0) {\n"
 "        Fiber.abort(\"Connection closed during handshake\")\n"
 "      }\n"
 "      response = response + chunk\n"
@@ -432,7 +432,7 @@ static const char* websocketModuleSource =
 "  readBytes_(count) {\n"
 "    while (Bytes.length(_readBuffer) < count) {\n"
 "      var chunk = _socket.read()\n"
-"      if (chunk == null || chunk.count == 0) {\n"
+"      if (chunk == null || chunk.bytes.count == 0) {\n"
 "        if (Bytes.length(_readBuffer) == 0) return null\n"
 "        var result = _readBuffer\n"
 "        _readBuffer = \"\"\n"
@@ -473,7 +473,7 @@ static const char* websocketModuleSource =
 "    var request = \"\"\n"
 "    while (true) {\n"
 "      var chunk = socket.read()\n"
-"      if (chunk == null || chunk.count == 0) {\n"
+"      if (chunk == null || chunk.bytes.count == 0) {\n"
 "        socket.close()\n"
 "        return null\n"
 "      }\n"