Note that on 1.9 you have to use each_line since each (and enumerable) have been removed from the String class.
JD From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dave Remy Sent: Monday, June 30, 2008 1:06 PM To: [email protected] Subject: Re: [Ironruby-core] MutableString.each After trying out various use cases string.each (synonym for .each_line) is very weird. Here are some cases .... # This one does not throw exception s = "aaa" s.each { s[0] = "b"} => "baa" # This one does (it has a newline) (and matches the rubyspec test case) s = "aaa\naaa" s.each { s[0] = "b"} => Runtime Error: string modified # Ok, if that is not weird enough (but maybe not completely whacked if you consider each_line won't really iterate until there is a newline) s = "aaa\naaa" # modify s before iterating s[0] = "a" s.each { s[0] = "b"} => "baa\naaa" This looks like MRI is relying on copy on write semantics to determine whether a string was modified? Jim, says this is not the behavior for 1.9. This seems like a good candidate for IR diverging on ... rem From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dave Remy Sent: Monday, June 30, 2008 9:47 AM To: [email protected] Subject: Re: [Ironruby-core] MutableString.each Translation: I need to check to assure that mri actually uses freeze to make the string immutable while iterating. I should be able to test the string for frozen. I just ran a test script, and nope, the string being iterated is not frozen: s = "aaa" s.each { puts s.frozen? } => false So I need to implement some other mechanism for making the iterated string immutable during the iteration rather than freezing it. I wonder whether other types of mutable objects that iterate have this same behavior ... I'll do some more research. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Lam (IRONRUBY) Sent: Monday, June 30, 2008 7:23 AM To: [email protected] Subject: Re: [Ironruby-core] MutableString.each You should catch and rethrow the correct exception if you want to use the frozen detection stuff. But you should check to see if it's actually frozen while iterating - ie is this an observable side-effect of using each? Thanks, -John From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Curt Hagenlocher Sent: Sunday, June 29, 2008 4:16 PM To: [email protected] Subject: Re: [Ironruby-core] MutableString.each RuntimeException is defined in IronRuby.Libraries\Builtins\Exceptions.cs. Is MRI really that inconsistent about which type of error is thrown when you try to modify a frozen object? (Not that this would surprise me :(.) If so, it might be cleaner if the call to FreezeObject could record or otherwise influence the type of exception that we expect to throw. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dave Remy Sent: Sunday, June 29, 2008 3:58 PM To: [email protected] Subject: [Ironruby-core] MutableString.each I am working on one of the specs for string.each which is failing. This is the spec that is failing. it "raises a RuntimeError if the string is modified while substituting" do str = "hello\nworld" should_raise(RuntimeError) { str.send(cmd) { str[0] = 'x' } } end The idea is that the string that is being iterated over shouldn't be changed during the iteration. It is easy enough to freeze the string in the first line of MutableString.EachLine using: RubyUtils.GetExecutionContext(context).FreezeObject(self); Which appropriately throws an error when the string gets modified, however this approach throws a "TypeError" and the spec wants a "RuntimeError" (message: String#each raises a RuntimeError if the string is modified while substituting FAILED, Expected RuntimeError, got TypeError (can't modify frozen object)). I considered wrapping the code in EachLine that invokes the each block with a try catch and then rethrowing a caught type error exception to a runtime exception however I don't see a runtime exception type in RubyExceptions. Any suggestions on how best to approach this? Thx! rem
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