Re: Compiler and interpreter origins

On 9 Aug 2004 00:28:14 -0400, "Nick Roberts" <nick.roberts@acm.org>
wrote:


> On 4 Aug 2004 02:44:48 -0400, Jeff Kenton <Jeffrey.Kenton@comcast.net>
[ asked about selfmodifying code in the Good Old Days ]


> Originally, the COBOL language had an
>
> ALTER x TO PROCEED TO y
>
> statement, which modified a GOTO statement (itself labelled x),
> changing its destination from whatever it was before to y. As you can
> imagine, programmers could -- and generally did -- achieve the most
> spectacularly obfuscated code with this statement. It became quite
> notorious, and quickly became deprecated and then removed from
> compilers altogether.
>
ALTER and "GO TO dot" are/were still in the 1985 standard, although
deprecated; I believe they have finally been actually removed in 2002
or thereabouts, I haven't been following closely, which is not very
quick as I think the first COBOL was mid-50's. I know of at least a
couple of compilers still in active use that implement -85 and so
support this "feature" -- though as you indicate it should be
violently shunned by all right-thinking programmers.


> Unfortunately, I think things have swung too far the other way, in
> that even the humble GOTO is now considered verboten. Silly.


- David.Thompson1 at worldnet.att.net

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