Discovering Dennis Ritchie’s Lost Dissertation • Hacker News Board

Re: Discovering Dennis Ritchie’s Lost Dissertation

#31

Post by smitty1e » Sat, Jun 20, 2020, 10:29 AM UTC

sradman wrote: post #25

W0lf wrote: post #9

So after reading this, is it correct to say that Ritchie basically showed in his thesis the application of the for loop for recursive prime number computation and also its application to computational complexity? AFAIK for loops where already known at the time since they first appeared in ALGOL a little earlier?

TLDR; Gödel’s incompleteness theorem rests on recursive functions which can be expressed as looping programs, i.e., for() loops. Dennis Ritchie’s PHD thesis, which was never accepted by Harvard because he refused to pay for a bound copy required for submission, demonstrated that the complexity of looping programs is determined by the degree of nesting. Ritchie did not seem to be driven by status seeking but instead b…

...and perhaps a hint of disdain for the 11th hour fee.

Re: Discovering Dennis Ritchie’s Lost Dissertation

#32

Post by dragonwriter » Sat, Jun 20, 2020, 10:36 AM UTC

einpoklum wrote: post #29

unixhero wrote: post #20

Earlier quoted context omitted.

Except every non programmer with a business degree seem to love functional programming: Microsoft Excel

Umm, doesn't Excel use Visual Basic (VBA) under the hood?

No, AFAIK, VBA is just a scripting layer exposed by Excel, not what Excel uses itself.

Re: Discovering Dennis Ritchie’s Lost Dissertation

#33

Post by pjmlp » Sat, Jun 20, 2020, 10:49 AM UTC

einpoklum wrote: post #29

unixhero wrote: post #20

Earlier quoted context omitted.

Except every non programmer with a business degree seem to love functional programming: Microsoft Excel

Umm, doesn't Excel use Visual Basic (VBA) under the hood?

Not at all, Excel can be scripted in multiple ways, VBA is just one among many.

Re: Discovering Dennis Ritchie’s Lost Dissertation

#34

Post by morelisp » Sat, Jun 20, 2020, 10:55 AM UTC

dang wrote: post #10

> My graduate school experience convinced me that I was not smart enough to be an expert in the theory of algorithms and also that I liked procedural languages better than functional ones. I wonder if that last bit was as unfashionable a statement when he made it as it would be now.

Since it was on his Bell Labs website, surely this phrasing of the feeling came no earlier than the late 80s, rather than when he left academia in '68? ("Functional programming" as a contrasting term seems to have barely existed before Backus's Turing Award lecture in '77.)

For the 80s and much of the 90s Ritchie's view seems obviously dominant, in no small part due to his own work in making extremely "usable" tools for procedural programming.

Re: Discovering Dennis Ritchie’s Lost Dissertation

#35

Post by dzdt » Sat, Jun 20, 2020, 10:58 AM UTC

unixhero wrote: post #20

tinco wrote: post #16

Earlier quoted context omitted.

Functional programming languages have alway been somewhat dismissed by most. Even though every once in a while functional programming becomes somewhat of a hot topic, only few programmers actually take it up as their main or favourite programming style. I'd say Ritchie's attitude there is and was kind of mainstream. I suppose just as C (or C style languages) have been mainstream for the past 40 years.

Except every non programmer with a business degree seem to love functional programming: Microsoft Excel

Excel is at its core a declarative programming language. Entering formulas in cells that reference other cells declares the relationship of the calculated cells to its referents.

It is not an imperative language: the user does not tell the computer which order in which to carry out computations. It is not procedural: there is no notion writing of procedures within its cells. It is not functional: while there are built-in functions users cannot write their own in the same way.

Re: Discovering Dennis Ritchie’s Lost Dissertation

#36

Post by Yaa101 » Sat, Jun 20, 2020, 11:00 AM UTC

dang wrote: post #10

> My graduate school experience convinced me that I was not smart enough to be an expert in the theory of algorithms and also that I liked procedural languages better than functional ones. I wonder if that last bit was as unfashionable a statement when he made it as it would be now.

In hindsight you can say he suffered from imposter syndrome. People often have trouble to accept that an easy working solution to a difficult problem is an act of genius, instead they feel that they took a shortcut and are non deserving.

Re: Discovering Dennis Ritchie’s Lost Dissertation

#37

Post by jimhefferon » Sat, Jun 20, 2020, 11:02 AM UTC

dang wrote: post #10

> My graduate school experience convinced me that I was not smart enough to be an expert in the theory of algorithms and also that I liked procedural languages better than functional ones. I wonder if that last bit was as unfashionable a statement when he made it as it would be now.

Is it possible that "functional programming" meant as in Kleene's Introduction to Metamathematics, where the work has a mathematical flavor with recursive functions, in contrast with FORTRAN or ALGOL or whatever language DR was using on physical machines at the time?

Re: Discovering Dennis Ritchie’s Lost Dissertation

#38

Post by auggierose » Sat, Jun 20, 2020, 11:17 AM UTC

linsomniac wrote: post #2

When I was a teen, K&R The C Programming Language changed my life. Years later I shared an elevator with him at Usenix. I always regretted not saying something to him, but I didn't have the words. Kids: If you meet your heroes, say something. "Thank you" is good if you don't have the words.

You are right :-) Shared the elevator with Dana Scott once at a conference in Seattle. Even exited it on the same floor, and we actually had hotel rooms next to each other. But I managed to say nothing to him :-D

Re: Discovering Dennis Ritchie’s Lost Dissertation

#39

Post by [deleted] » Sat, Jun 20, 2020, 11:20 AM UTC

verytrivial wrote: post #28

Taniwha wrote: post #18

So what would happen if we took up a collection, produced a bound copy, and sent it off to Harvard?

Policy or not, it would perhaps be nice to deposit a copy anyway. Put the ball in their court so to speak, even if Harvard does nothing further.

[deleted]

Re: Discovering Dennis Ritchie’s Lost Dissertation

#40

Post by 082349872349872 » Sat, Jun 20, 2020, 11:24 AM UTC

morelisp wrote: post #34

dang wrote: post #10

> My graduate school experience convinced me that I was not smart enough to be an expert in the theory of algorithms and also that I liked procedural languages better than functional ones. I wonder if that last bit was as unfashionable a statement when he made it as it would be now.

Since it was on his Bell Labs website, surely this phrasing of the feeling came no earlier than the late 80s, rather than when he left academia in '68? ("Functional programming" as a contrasting term seems to have barely existed before Backus's Turing Award lecture in '77.) For the 80s and much of the 90s Ritchie's view seems obviously dominant, in no small part due to his own work in making extremely "usable" tools…

Reading CACM on 50-year delay gives me an interesting diff against current state of the art. Functional programming was a thing (albeit perhaps before "functional programming" was a name) in the sixties.

CPL, IIRC, actually had an outer-functional semantics, and one would escape to "value of" blocks to do procedural stuff (which was necessary in inner code due to the pitifully small machines of the day).

Writing bootstrap compilers in GPM must've been very similar to working in a lazy functional language.