from: Accept a callback function.

lib/index.js

@@ -308,30 +308,44 @@ const Channel = function(length = 0) {
 
 Channel.from = values => {
   const channel = Channel();
+
   (async () => {
+    // iterable
     try {
-      // iterable
       for (let value of values) {
         await channel.push(value);
       }
 
       await channel.close();
     } catch (exception) {
-      // Assume it's a Node.js stream.readable.
+      // callback function
+      try {
+        for (;;) {
+          const value = values();
 
-      values.on("readable", async () => {
-        while (true) {
-          const data = values.read();
-
-          if (data === null) {
+          if (value === undefined) {
+            await channel.close();
             break;
           } else {
-            await channel.push(data);
+            await channel.push(value);
           }
         }
-      });
+      } catch (exception) {
+        // Node.js stream.readable
+        values.on("readable", async () => {
+          while (true) {
+            const data = values.read();
 
-      values.once("end", channel.close);
+            if (data === null) {
+              break;
+            } else {
+              await channel.push(data);
+            }
+          }
+        });
+
+        values.once("end", channel.close);
+      }
     }
   })();