On 21/12/2021 18:07, Bakul Shah wrote:
> On 12/14/21 2:58 AM, James Harris wrote:
>> How can someone make sure a new language is 'complete', i.e. that no
>> essential is left out and that it will allow a programmer to do
>> anything he might need to do?
>>
>> The reason for asking is that I recently realised that I had to add a
>> new parameter mode. Because of certain choices I found I couldn't get
>> away with just in, inout and out so I had to add a new mode. I'm
>> avoiding going in to the details as they could divert from the topic
>> but the point is that I found that something was missing and it got me
>> wondering what else could be needed.
>>
>> So is there a way to make sure a new language is complete?
>>
>> AISI first of all there's computational or 'Turing' completeness. For
>> that, perhaps it's enough to ensure that the language has selections
>> and loops. But then there are other things - such as the
>> parameter-mode example, above. How does one make sure nothing is missing?
>>
>> One approach is probably to base a new language on an existing one.
>> Then as long as the earlier language is complete it should be easier
>> to make sure the new one is, too. But even that has its weaknesses.
>> For example, one might base a new language on C but then find that
>> some things cannot be done - or cannot be done reasonably - without
>> the preprocessor.
>>
>> If attempting to create a new language without an antecedent then the
>> situation is even more challenging. There will be no prior model to
>> guide the design.
>>
>> So, any suggestions?
>
> Have you read "Hints on Programming Language Design" by Tony Hoare?
>     http://flint.cs.yale.edu/cs428/doc/HintsPL.pdf
> Published in 1974 but still worth reading.

Not sure if I had before but I've just read through it. Hoare doesn't
really deal with making sure a language is complete and some of his
comments relate to the time when the paper was written. But others of
them are timeless. It's a pity there aren't thinkers of his type still
around - at least I don't know of any.

--
James Harris

On 09/12/2023 13:51, James Harris wrote:
> [...] Hoare doesn't
> really deal with making sure a language is complete and some of his
> comments relate to the time when the paper was written. But others of
> them are timeless. It's a pity there aren't thinkers of his type
> still around - at least I don't know of any.

Tony Hoare is still around. So are, for example, Don Knuth,
Niklaus Wirth, Brian Kernighan, Ken Thompson, Steve Bourne, Michael
Jackson and many others, just to mention some of those active more
than 40 years ago. I don't know how many of them are /still/ active.
Fred Brooks and Charles Lindsey died fairly recently.

Personal note: while checking up on TH, I discover that he was
awarded a Royal Society medal this year, along with Herman [monoclonal
antibodies] Waldmann, who was a friend of mine at college.

--
Andy Walker, Nottingham.
Andy's music pages: www.cuboid.me.uk/andy/Music
Composer of the day: www.cuboid.me.uk/andy/Music/Composers/Richards

On 09/12/2023 17:41, Andy Walker wrote:
> On 09/12/2023 13:51, James Harris wrote:
>> [...] Hoare doesn't
>> really deal with making sure a language is complete and some of his
>> comments relate to the time when the paper was written. But others of
>> them are timeless. It's a pity there aren't thinkers of his type
>> still around - at least I don't know of any.
>
>     Tony Hoare is still around.  So are, for example, Don Knuth,
> Niklaus Wirth, Brian Kernighan, Ken Thompson, Steve Bourne, Michael
> Jackson and many others, just to mention some of those active more
> than 40 years ago.  I don't know how many of them are /still/ active.
> Fred Brooks and Charles Lindsey died fairly recently.

Sad to hear about Charles Lindsey, in particular, as many of us
discussed language issues with him on this newsgroup.

--
James Harris

On 09/12/2023 17:41, I wrote:
> On 09/12/2023 13:51, James Harris wrote:
>> [...] It's a pity there aren't thinkers of [Hoare's] type
>> still around - at least I don't know of any.
>     Tony Hoare is still around.  So are, for example, Don Knuth,
> Niklaus Wirth, [...].

Sadly, Niklaus Wirth died on Monday, January 1st, aged 89.
Biography at, eg, "https://en.wikipedia.org/wiki/Niklaus_Wirth".

RIP.

--
Andy Walker, Nottingham.
Andy's music pages: www.cuboid.me.uk/andy/Music
Composer of the day: www.cuboid.me.uk/andy/Music/Composers/Bizet