[Info-vax] Pascal question

[Dave Froble]

On 1/21/2019 8:44 PM, John Reagan wrote:
> On Monday, January 21, 2019 at 8:34:32 PM UTC-5, Arne Vajhøj wrote:
>> On 1/21/2019 8:23 PM, Bill Gunshannon wrote:
>>> On 1/21/19 6:56 PM, Dave Froble wrote:
>>>> Actually, while at the risk of wasting your valuable time, I'd ask,
>>>> why would Pascal as implemented by you not already have such a
>>>> function? Understand, I don't use Pascal.  Was string handling not a
>>>> featured part of the language?
>>>
>>> The original Pascal as defined by Niklaus Wirth didn't have
>>> a string type at all.
>>
>> First version of his paper actually had an alfa type that seems
>> very similar to a string.
>>
>> In the 1973 version and forward it was all packed array of char.
>>
>> Arne
>
> ALFA was a PACKED ARRAY [1..10] OF CHAR.  60-bits to fit in a CDC-6400 register with 6-bit characters.
>
> Extended Pascal added a variable string STRING() type that is almost identical to our VARYING OF CHAR type (which itself was modeled on PL/1's VARYING OF CHAR).
>
> As for string manipulation, like upcase, it hasn't been a popular request.
>

Perhaps because anyone needing it already had a solution, or used an 
existing external routine?

John, did any other languages (besides Basic) use the VMS dynamic string 
types?

The implementation on Basic+ was rather interesting.  If one set string 
A$ = B$, it would not copy the data, it changed the pointer for A$ to 
the same value as the pointer for B$.  Things could get interesting.  If 
A$ was a label in an I/O buffer, it would no longer be a label in the 
buffer.

:-)

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