[Simh] Fwd: [TUHS] An abandoned piece of K&R C

[Larry Stewart]

I took the liberty of cross posting this earlier to TUHS and I got 
an authoritative answer :)
-Larry


> Begin forwarded message:
> 
> From: Ken Thompson <ken at google.com>
> Subject: Re: [TUHS] Fwd: [Simh] An abandoned piece of K&R C
> Date: 2017, November 3 at 2:30:08 PM EDT
> To: Lawrence Stewart <stewart at serissa.com>
> 
> it's news to me.
> 
> 
> On Fri, Nov 3, 2017 at 5:53 AM, Lawrence Stewart <stewart at serissa.com> wrote:
>> This caught my attention.  Did early C really have min and max?  Were they
>> used for anything?  In those days I was a BCPL user, which IIRC, did not
>> have such things.
>> 
>> -Larry
>> 
>> Begin forwarded message:
>> 
>> From: Leo Broukhis <leob at mailcom.com>
>> Subject: [Simh] An abandoned piece of K&R C
>> Date: 2017, November 3 at 1:14:42 AM EDT
>> To: "simh at trailing-edge.com" <simh at trailing-edge.com>
>> 
>> https://retrocomputing.stackexchange.com/q/4965/4025
>> 
>> 
>> In the UNIX V7 version of the C language, there were the /\ (min) and the \/
>> (max) operators. In the source of the scanner part of the compiler,
>> 
>> case BSLASH:
>>    if (subseq('/', 0, 1))
>>        return(MAX);
>>    goto unkn;
>> 
>> case DIVIDE:
>>    if (subseq('\\', 0, 1))
>>        return(MIN);
>> ...
>> 
>> However, attempting to use them reveals that the corresponding part in the
>> code generator is missing. Trying to compile
>> 
>> foo(a, b) { return a \/ b; }
>> 
>> results in
>> 
>> 1: No code table for op: \/
>> 
>> The scanner piece survived in the copies of the compiler for various systems
>> for several years. I tried to look for copies of the code generator table
>> which would contain an implementation, but failed. Has anyone ever seen a
>> working MIN/MAX operator in K&R C?
>> 
>> Thanks,Leo
>> 
>> _______________________________________________
>> Simh mailing list
>> Simh at trailing-edge.com
>> http://mailman.trailing-edge.com/mailman/listinfo/simh
>> 
>> 

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