Re: Jensen's device

xxx@info.lv wrote:


>1. When they discovered the mistake, why didn't they simply rewrite the
> document containing the definition of Algol-60? I assume, it was not
> so easy because of all that bureaucratic work :-(


Speaking of language "mistakes": I had the misfortune of taking a class in
PL/I back in the 70's. That was still a time of punched cards. PL/I
statements (on an IBM machine) had to start in column 2 or greater. This
seemed perplexing at first. What was so damn special about column 1 that we
couldn't touch it. A classmate made the connection and pointed out that the
problem was the open-comment delimiter: '/*'. Those with past experience
with IBM JCL (or OCL for you System/3 fans) will remember that a punched card
containing '/*' in column 1 was and end-of-file marker.


I often wondered if PL/I design commitee realized the conflict late in the
project and decided it would be easier to insist that PL/I statements not
start in column 1.


Scott Amspoker
scott@basis.com
http://www.rt66.com/sda
[My dim recollection is that col 1 contained some sort of preprocessor
flag, but I can easily believe that the /* problem was the real motivation.
PL/I and JCL were designed at IBM at the same time, and it would be typical
for the two groups not to talk to each other. -John]




--

Return to the comp.compilers page.
Search the comp.compilers archives again.