Question

I am trying to find in a huge COBOL file if all the "IF" have a corresponding "END-IF". Using Visual Studio 2008 as I know it has a search tool with a regex feature. (Though, I know after reading Jeff Atwood s article about it, that the regex in Visual Studio are not quite the same than the real deal.)

Anyway, I came up with this expression:

<(IF)#(.*
*)#END-IF

That seems to overflow the stack, quite inconveniently (see picture below). So I was wondering, if it was at all possible to do this kind of search in VS ? And if it is, what would the regex look like ?

-->I want to know if all "IF" have a closing "END-IF"

感谢。

“stack

Answer 1

What you have here is a case of trying to perform recursive parsing with a regular expression, and generally that s going to get you into trouble. As I read it (granted, I am not familiar with the flavor used by Visual Studio here), your regex tries to match as many lines as it can until it finds an END-IF -- including matching another END-IF. In other words, when presented with

IF condition-1
    statement-1
END-IF
IF condition-2
    statement-2
END-IF

one match is found, not two.

Also, think about how you want to deal with this case:

IF condition-1
    IF condition-2
        statement-1
    END-IF
END-IF

除非你试图书写自己的语言翻译或COBOL灯塔工具,否则,我认为你可以听说,编辑们将找到你相应的数字,或者在一段末尾悬挂一个未公开的综合框架。

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