Hello,
I am very pleased that I got everything working and found iron ruby in a
quite usable state for me. Congratulations.
Question: How do you set a global variable from C#? I found a workaround
via
setting a local variable scope.SetVariable(“a”, obj) in the scope and
assigning it to a global via engine.Execute("$a=a", scope).
The Runtime.Globals.GetVariable and SetVariable don’t seem to get / set
the
ruby globals.
Please clarify.
BTW: as for local variables: scope.GetVariableNames() does return an
empty
list. Again a workaround is Execute(“local_variables”, scope).
– henon
On Mon, Feb 9, 2009 at 12:12 PM, Meinrad R.
[email protected]wrote:
Oh, i just found out that ScriptScope.GetVariable is throwing an
exception
…
ArgumentNullException: “Value cannot be null.
Parameter name: field”
On Mon, Feb 9, 2009 at 1:05 PM, Meinrad R.
[email protected]wrote:
assigning it to a global via engine.Execute(“$a=a”, scope).
Parameter name: field"
Microsoft.Scripting.Utils.ContractUtils.RequiresNotNull(Object value,
String paramName)
Microsoft.Scripting.SymbolTable.StringToId(String field)
Microsoft.Scripting.Hosting.ScriptScope.GetVariable(String name)
sorry forgot to say, that I made sure, that the “name” parameter is
not
null.
I am not yet deep enough into the sources to fix things like these
myself.
– henon
On Mon, Feb 9, 2009 at 1:11 PM, Meinrad R.
[email protected]wrote:
sorry forgot to say, that I made sure, that the “name” parameter is not
null.
I am not yet deep enough into the sources to fix things like these myself.
– henon
ok, I was too fast on this one. actually it was null because a
ruby_string
casted to c# string is null. It is pretty dangerous to assume a value
presented as “a” by the debugger to be a System.String when that value
comes
out from ruby 
so the problem is not the exception but rather that GetVariable(“a”)
does
not find existing local variables which can be evaluated by
Execute(“a”).
This time I made sure I made no mistake.
You can find many hosting examples in HostingTests.cs.
As for global and top-level local variables:
global constants (ie. constants on Object).
top-level local variables. They are looked up via method_missing on a
top-level singleton object. Ruby top-level program executes in a context
where “self” is a singleton of Object. IronRuby defines method_missing
on this singleton. If a method name ends with “=” it writes to the
scope, otherwise it reads from the scope.
ScriptScope scope = Engine.CreateScope();
scope.SetVariable(“x”, 1);
scope.SetVariable(“y”, 2);
Engine.Execute(“self.z = x + y”, scope);
int result = scope.GetVariable(“result”);
Assert(result == 3);
Ruby global variables don’t have any mapping to DLR scopes. We don’t
have any well designed API for them yet, you can do this for now:
Ruby.GetExecutionContext(Engine).DefineGlobalVariable(“foo”, 123);
Tomas
From: [email protected]
[mailto:[email protected]] On Behalf Of Meinrad
Recheis
Sent: Monday, February 09, 2009 3:13 AM
To: ironruby-core
Subject: [Ironruby-core] setting global variables in embedded ironruby
interpreter
Hello,
I am very pleased that I got everything working and found iron ruby in a
quite usable state for me. Congratulations.
Question: How do you set a global variable from C#? I found a workaround
via setting a local variable scope.SetVariable(“a”, obj) in the scope
and assigning it to a global via engine.Execute(“$a=a”, scope).
The Runtime.Globals.GetVariable and SetVariable don’t seem to get / set
the ruby globals.
Please clarify.
BTW: as for local variables: scope.GetVariableNames() does return an
empty list. Again a workaround is Execute(“local_variables”, scope).
– henon