Hi Mariano, _,,,^..^,,,_ (phone)
On Jul 24, 2017, at 9:21 AM, Mariano Martinez Peck <marianopeck@gmail.com> wrote:
Hi guys,
Is there a portable (that would work in GemStone too) and safe way to know if a String would be a block?
I must support this kind of strings:
'singleString' -> false 'multi string' -> false ' [:a | 42]' -> true ' '' '' [:a | 42]' -> true '[:a | 42]' -> true ' "a commet" [:a | 42]' -> true ' WhateverClass someVeryBadHackishMethod. [:a | 42]' -> true
I need to identify whether the string is a closure or not. And ideally, I don't want to do an #evaluate: because I don't want any left hand code to be executed. I tried with #parse: why I am having problems.
Any ideas?
Not sure if you're still stuck but if you dive into evaluate: you'll be able to find the point at which it parses, and find out how to invoke the parser for an expression (a doit). evaluate: parses an expression so you want to check that the resulting parse tree is that of a return node whose expression is a literal block. You can also check the block's argument count. Once you've extracted the parser invocation you can wrap this in a suitable exception handler. Then you have your block parser. You still have to validate the parse tree and/or generated code before evaluating since someone could write malicious code within the block right?
Thanks in advance
-- Mariano http://marianopeck.wordpress.com