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--- at:tutorial:actors [2008/11/04 10:11] – added tvcutsem
+++ at:tutorial:actors [2008/11/04 10:16] – added tvcutsem
@@ Line 469: / Line 469: @@
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-If both the ''outer'' and ''inner'' actors lexically see ''x'', they could modify it concurrently, reintroducing race conditions on the internal state of an actor. Therefore, when defining an actor using a block of code, we disallow access to the enclosing lexical scope by the new actor. It is as if it was defined at top-level. Hence, actors behave similarly to [[#isolates|isolates]] in this respect. The above example is incorrect in that ''inner'' will not be able to read or modify ''x''.
+If both the ''outer'' and ''inner'' actors lexically see ''x'', they could modify it concurrently, reintroducing race conditions on the internal state of an actor. Therefore, when defining an actor using a block of code, we disallow direct access to the enclosing lexical scope by the new actor. Actors behave similarly to [[#isolates|isolates]] in this respect. The above example code will work, but the programmer has to keep in mind that the ''x'' variable accessed by ''inner'' is a //copy// of the ''x'' variable of ''outer''. Hence, assignments to ''x'' by ''inner'' will not affect ''outer'' and vice versa.
-Recall that isolates could be given selective access to their enclosing lexical scope by specifying accessed variables as formal parameters to their initializing closure, which gave rise to copying the variable into the isolate. We allow actors to do the same. Hence, the above example can be written properly as:
+Recall that isolates could be given access to their enclosing lexical scope either by specifying accessed variables as formal parameters to their initializing closure or by having the interpreter derive the lexically free variables automatically. If the programmer wants to make explicit the fact that ''x'' is copied, the example can also be rewritten as:
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