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--- at:tutorial:appendix [2010/05/26 19:39] – *fixed tvcutsem
+++ at:tutorial:appendix [2020/02/05 20:57] – adding elisag
@@ Line 392: / Line 392: @@
 The files in the ''at/lang'' directory define custom language features which mostly use AmbientTalk/2's reflective facilities to extend the language.
-==== Futures and Multifutures ====
-=== Futures ===
+==== Futures ====
 The module ''/.at.lang.futures'' provides support for futures. Futures have already been described as part of the [[:at:tutorial:actors#futures|concurrency]] section in the tutorial.
@@ Line 417: / Line 416: @@
 </code>
-Finally, the futures module also provides some auxiliary functions, of which ''group:'' is often a very useful one. The ''group:'' construct groups a table of futures into a single future which is resolved with a table of values or ruined with an exception:
+=== Auxilary functions in the futures module ====
+The futures module also provides some auxiliary functions, of which ''group:'' is often a very useful one. The ''group:'' construct groups a table of futures into a single future which is resolved with a table of values or ruined with an exception:
 <code>
-when: (group: [ a<-m(), b<-n() ]) becomes: { |values|
+when: (group: [ a<-m()@FutureMessage, b<-n()@FutureMessage ]) becomes: { |values|
   def [aResult, bResult] := values;
   ...
@@ Line 426: / Line 427: @@
 </code>
-=== Multifutures ===
+Another useful auxilary function is ''future:'' construct which returns a future which is resolved with the value passed to the 'reply' closure:
+<code>
+future: { |return|
+  // some computation
+  return(val)
+}
+</code>
+This is actually equivalent to the slightly more verbose code:
+<code>
+def [fut,res] := makeFuture();
+try: { // some computation
+  res.resolve(val);
+} catch: Exception using: { |e| res.ruin(e) }
+fut;
+</code>
+==== Multifutures ====
 The module ''/.at.lang.multifutures'' provides support for multifutures. A multifuture is a future that can be resolved multiple times. We distinguish between 'bounded multifutures', which can be resolved up to a maximum number and 'unbounded multifutures' which have no upper bound.