Ambient-Oriented Programming

User Tools

Site Tools

Trace:
at:tutorial:appendix

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision		Previous revision
Next revisionBoth sides next revision
at:tutorial:appendix [2009/01/29 21:56] – * elisagat:tutorial:appendix [2020/02/05 21:01] – * elisag
Line 27: Line 27:
 This will execute all ''test*'' methods in the given unit test (in an **undefined** order!), and print out which of the tests succeeded or failed. The ''runTest'' method can optionally take a "reporter" object as an argument, which can be used to implement a custom strategy for reporting success or failure of a unit test. The default reporter object is a text-based UI. This will execute all ''test*'' methods in the given unit test (in an **undefined** order!), and print out which of the tests succeeded or failed. The ''runTest'' method can optionally take a "reporter" object as an argument, which can be used to implement a custom strategy for reporting success or failure of a unit test. The default reporter object is a text-based UI.
  
-Like in JUnit and SUnit, it is possible to define two methods named ''setUp()'' and ''tearDown()'' that are invoked in between //each// individual ''test*'' method. Never rely on the lexical order of your unit test methods for the purposes of initialization, etc.! Unit test methods may be exacuted in an arbitrary order.+Like in JUnit and SUnit, it is possible to define two methods named ''setUp()'' and ''tearDown()'' that are invoked in between //each// individual ''test*'' method. Never rely on the lexical order of your unit test methods for the purposes of initialization, etc.! Unit test methods may be executed in an arbitrary order.
  
 ==== Assertions ==== ==== Assertions ====
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. 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. 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 418:
 </code> </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:+The ''makeFuture'' function can also take a timeout. If a timeout is given it returns a returns a pair [lease, resolver]  where the lease timer gets immediately activated. If the future is not resolved within the given timeout, the lease expires and ruins the future with a ''TimeoutException''. Note that this means a lease will get parameter-passed rather than the future if given to other actors. 
 + 
 +=== 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> <code>
-when: (group: [ a<-m(), b<-n() ]) becomes: { |values|+when: (group: [ a<-m()@FutureMessage, b<-n()@FutureMessage ]) becomes: { |values|
   def [aResult, bResult] := values;   def [aResult, bResult] := values;
   ...   ...
Line 426: Line 431:
 </code> </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. 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.
Line 472: Line 496:
  
 <note> <note>
-The implementation of leased object references actually consists of two files: ''/.at.lang.leasedrefs'' and ''/at.lang.leasedrefstrait''. ''leasedrefstrait'' module implements the common behaviour to the different types of leased references. This module is imported in the ''leasedrefs'' module which provides the public API for creating and managing leased object references.+The implementation of leased object references actually consists of two files: ''/.at.lang.leasedrefs'' and ''/at.lang.leasedrefstrait''. ''leasedrefstrait'' module implements the behaviour common to the different types of leased references. This module is imported in the ''leasedrefs'' module which provides the public API for creating and managing leased object references.
 </note> </note>
  
 The ''leasedrefs'' module exports language constructs to create three different types of leased object references: The ''leasedrefs'' module exports language constructs to create three different types of leased object references:
   * ''lease:for:''returns a leased reference that remains valid for the indicated time interval.   * ''lease:for:''returns a leased reference that remains valid for the indicated time interval.
-  * ''renewOnCallLease:for:'' returns a leased reference that it is automatically renewed each time the remote object receives a message with the specified time interval.+  * ''renewOnCallLease:for:'' returns a leased reference that is automatically renewed (with the specified time interval) each time the remote object receives a message.
   * ''singleCallLease:for:'' returns a leased reference that remains valid for only a single method call on the remote object.   * ''singleCallLease:for:'' returns a leased reference that remains valid for only a single method call on the remote object.
  
-Variations of these constructs are also provided to allow developers to specify the renewal time interval in renew-on-call leased references and the name(s) of the method(s) which expires a single-call leased reference.+Variations of these constructs are also provided to allow developers to specify the renewal time interval in renew-on-call leased references and the name(s) of the method(s) which trigger expiration of a single-call leased reference.
  
-The ''leasedrefs'' module also provides the following constructs to explicit manage the lifetime of leased references:+The ''leasedrefs'' module also provides the following constructs to explicitly manage the lifetime of leased references:
  
 <code> <code>
-renew: leasedRef for: interval; +renew: leasedRef for: interval; // renews a lease 
-revoke: leasedRef; +revoke: leasedRef; // revokes a lease 
-leaseTimeLeft: leasedRef;+leaseTimeLeft: leasedRef; // return time left until lease expires 
 +when: lease expired: {...}; // trigger a closure when the lease expires
 </code> </code>
  
-''when:expired'' construct is provided to schedule clean-up actions with a leased reference upon its expiration.+The ''when:expired:'' construct is provided to schedule clean-up actions with a leased reference upon its expiration.
  
 Finally, the ''leasedrefs'' module exports support primitives to manipulate time intervals (i.e. ''minutes'', ''seconds'', ''millisecs'') so that developers do not need to explicitly import the timer module to use leased references. Finally, the ''leasedrefs'' module exports support primitives to manipulate time intervals (i.e. ''minutes'', ''seconds'', ''millisecs'') so that developers do not need to explicitly import the timer module to use leased references.
Line 652: Line 677:
 ==== Object Inspector ==== ==== Object Inspector ====
  
-The module ''/.at.support.inspector'' implements a graphical object inspector. The module requires ''java.awt'' and ''javax.swing'' support from the underlying JVM running AmbientTalk. To inspect an object ''o'', execute:+The module ''/.demo.inspector'' implements a graphical object inspector. The module requires ''java.awt'' and ''javax.swing'' support from the underlying JVM running AmbientTalk. To inspect an object ''o'', execute:
  
 <code> <code>
-import /.at.support.inspector;+import /.demo.inspector;
 inspect(o); inspect(o);
 </code> </code>
at/tutorial/appendix.txt · Last modified: 2021/09/24 10:28 by elisag