Re: [DNG] OT: some ancient programming language history
On Mon, Jul 27, 2015 at 5:16 PM, Lars Noodén lars.noo...@gmail.com wrote: IIRC the Icon programming language had an exchange operator to swap the contents of two variables. a :=: b C: a = a ^ b; b = a ^ b; a = a ^ b; Much more fun. Them :=: look like weird emoticons. -- On the internet, nobody knows you're a dog. ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
T.J, would you please try to put dyne.org as To instead of CC, in the destination? I think it would enable the button reply to the list in Thunderbird. Le 27/07/2015 02:28, T.J. Duchene a écrit : The affectation operator is := instead of = in C, and the comparison are = (instead of ==) and /= instead of != . The bad choice of operators, together with other tricks is probably the main source of bugs in C programs. I like the fact that Ada is very strict, because it forces new programmers to do things right. On the other hand, that comes at the cost of flexibility, which makes it useless for certain tasks. Since C predates Ada by at least a decade, I don't think C is the problem. I have never had a problem keeping ==, = or != straight. I'm not a teacher and therefore can mostly speak for myself. I learned ALGOL in 1972, as already written, and then stopped programming for 6 years. Then I learned FORTRAN, which has the same assignment symbol as C, '=' . I discovered C in 1981 and used it up to now, which makes a honestly long experience, and it still happens to me to type '=' instead of '=='. The first Ada compiler appeared in 1983. It advertized some interesting features and I read a manual, then forgot it because I hadn't access to a compiler. This first compiler was running on VMS I think. I remember the year very well for other reasons. So you cannot believe I was contaminated by the use of ALGOL-like languages. Using C after FORTRAN, was a liberation. I could do a lot of things previously impossible. And there was structs and pointers. I loved programming in C. Later I wrote multitask and multithreaded DAQ programs. And discovered that a large program becomes rapidly un-maintainable, unless you work at least weekly on it. Around 1994 I had the project of a large multi-host DAQ system and I decided to select an appropriate language because C was too low-level. I selected Ada after months of enquiry, reading various opinions and comparisons, without knowing the language at all. Then I had, by chance, the opportunity to follow a one week lecture in 1995 and came out thinking I would never write applications in any other language. I had the opposite opinion about C++ 5 years before after a one week lecture also. C is a universal assembler. It is cast after the hardware. A unique feature of C is that an assignment has a value; this is because the value which has just been stored into memory is still there in a register, ready for use. It can be assigned to another variable (stored in another location), which allows instructions like a=b=c; while b=c; a=b; would mean an additional and useless load. C compilers have long been able to optimize out the additional load, but the instruction is still valid. A lot of C features are driven by the will to give the programmer a quasi-direct access to machine instructions. This includes the case explained above and pre-increment and post-increment instructions. But it makes no sense with modern compilers. The compiler now wipes out these optimizations the programmer may think xe has done, reorders the instructions, bypasses memory access for non-volatile variables and optimizes the whole better than you could do. It remains these funny features which are the trademark of C but are nothing but a danger. If you never make the mistake of using a single = in a comparison, then either you have a trick, or you are super-human. Whatever error is possible to do, a human will do it for sure. Gcc now gives a warning in such cases, but it's enough to enclose in parentheses to avoid the warning. When you write C predates Ada, you probably mean there are more people programming in C than Ada. So what? That tells nothing on the respective merits of the two languages. The fact is there hasn't been a good Ada compiler for a decade, because it is a difficult job to write one, while, in the contrary, C had been designed to make it easy to write compilers. The lack of good Ada compilers is probably one of the reasons for the later success of C++ (which started as a C preprocessor). C enables writing little things quickly and easily; for large things, it takes an infinite time to erradicate bugs. Ada is just the opposite: bad constructs are forbidden and the compiler checks a great many things. It takes longer to have your program compile without error, but then it works. There still remains a few possible bugs which cannot be found at compile time, but they will rather cause a crash than produce wrong results. At the end, you save time. Always. Sorry for this very long mail. I should better have a web site like Steve, and post links. Didier ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
Le 27/07/2015 17:45, Renaud (Ron) OLGIATI a écrit : On Mon, 27 Jul 2015 11:20:03 -0400 Renaud (Ron) OLGIATI ren...@olgiati-in-paraguay.org wrote: Or, as in APL, use = for assignment You mean like in b+c = a ? Interesting because assignment is an invention of imperative languages with no natural reason for the destination to be on the left side. Sorry, read use A (left arrow) 1 2 3 4 for assignment Don't understand what you mean :-) Didier ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On 07/27/2015 07:07 PM, Didier Kryn wrote: Le 27/07/2015 17:45, Renaud (Ron) OLGIATI a écrit : On Mon, 27 Jul 2015 11:20:03 -0400 Renaud (Ron) OLGIATI ren...@olgiati-in-paraguay.org wrote: Or, as in APL, use = for assignment You mean like in b+c = a ? Interesting because assignment is an invention of imperative languages with no natural reason for the destination to be on the left side. IIRC the Icon programming language had an exchange operator to swap the contents of two variables. a :=: b Or something like that. Regards, /Lars ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On Sun, Jul 26, 2015 at 11:58:55PM +0200, Didier Kryn wrote: ... The affectation operator is := instead of = in C, and the comparison are = (instead of ==) and /= instead of != . The bad choice of operators, together with other tricks is probably the main source of bugs in C programs. It you only program one language in your life, of course this doesn't matter much. But if you frequently change languages, you rapidly find: = is a bad choice for assignment, because it also means equality. = is a bad choice for equality, because it also means assignment. So the only sane choice is to use := for assignment and == for equality. Forget about = altogether. -- hendrik ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On Mon, 27 Jul 2015 11:20:03 -0400 Renaud (Ron) OLGIATI ren...@olgiati-in-paraguay.org wrote: Or, as in APL, use = for assignment Sorry, read use A (left arrow) 1 2 3 4 for assignment Cheers, Ron. -- And it should be the law: If you use the word `paradigm' without knowing what the dictionary says it means, you go to jail. No exceptions. -- David Jones -- http://www.olgiati-in-paraguay.org -- ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On Mon, 27 Jul 2015 10:32:06 -0400 Hendrik Boom hend...@topoi.pooq.com wrote: But if you frequently change languages, you rapidly find: = is a bad choice for assignment, because it also means equality. = is a bad choice for equality, because it also means assignment. So the only sane choice is to use := for assignment and == for equality. Forget about = altogether. Or, as in APL, use = for assignment and = for equality (all in one line ;-3) Cheers, Ron. -- And it should be the law: If you use the word `paradigm' without knowing what the dictionary says it means, you go to jail. No exceptions. -- David Jones -- http://www.olgiati-in-paraguay.org -- ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On Mon, 27 Jul 2015 18:07:30 +0200 Didier Kryn k...@in2p3.fr wrote: use A (left arrow) 1 2 3 4 for assignment Don't understand what you mean :-) (letter A) (left arrow symbol) (one or several values or variables) You mean like in b+c = a ? that would be: (letter a) (left arrow symbol) (b + c) Cheers, Ron. -- Animals can be driven crazy by putting too many in too small a pen. Homo sapiens is the only animal that voluntarily does this to himself. -- Lazarus Long -- http://www.olgiati-in-paraguay.org -- ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On 07/26/2015 11:08 AM, Hendrik Boom wrote: I also had a long discussion with some of the guys in charge of the ADA project -- they really wanted the security that comes from completely automatic storage management but they couldn't afford to have their weapons systems stop for garbage collection, I told them exactly what the trade-offs were -- too what extent they could have their cake and eat it too. In the end they decided that they could afford neither the language complexity of the garbage-collector-free storage management schemes, nor the garbage collection delays. I'm not sure to what extent they ended up avoiding dynamically allocated storage in the first official language definition. ADA! I remember that! I've not used it in the better part of 20 years. Nicely designed language for its time - and very strict. Having learned C in advance of ADA, I never liked its Pascal style operators. Too bad the only one who really uses it in the US is the government. I think you can find the answer to your memory comment here, Hendrik. https://en.wikipedia.org/wiki/Ada_(programming_language) T.J. ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
T.J. Duchene wrote: ADA! I remember that! I've not used it in the better part of 20 years. Nicely designed language for its time - and very strict. Having learned C in advance of ADA, I never liked its Pascal style operators. Too bad the only one who really uses it in the US is the government. Actually, not true. ADA seems to have a major following in the real-time control systems community, for mission/life-critical systems like avionics and SCADA. Not surprising, actually - it was designed for that kind of thing. Miles Fidelman -- In theory, there is no difference between theory and practice. In practice, there is. Yogi Berra ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
Le 26/07/2015 20:19, T.J. Duchene a écrit : On 07/26/2015 11:08 AM, Hendrik Boom wrote: I also had a long discussion with some of the guys in charge of the ADA project -- they really wanted the security that comes from completely automatic storage management but they couldn't afford to have their weapons systems stop for garbage collection, I told them exactly what the trade-offs were -- too what extent they could have their cake and eat it too. In the end they decided that they could afford neither the language complexity of the garbage-collector-free storage management schemes, nor the garbage collection delays. I'm not sure to what extent they ended up avoiding dynamically allocated storage in the first official language definition. ADA! I remember that! I've not used it in the better part of 20 years. Nicely designed language for its time - and very strict. Having learned C in advance of ADA, I never liked its Pascal style operators. Too bad the only one who really uses it in the US is the government. Ada is not an acronym, it's after the first name of the first person who wrote programs, the daughter of Byron, the english poet. Ada is used in many places where human life is at stake: eg. planes, missiles, Eurocontrol (the european air cirulation regulation), the driver-less metro in Paris. The initial version was Ada83. There have been some revisions since. Add95 was a major one and the last is Ada2012. The affectation operator is := instead of = in C, and the comparison are = (instead of ==) and /= instead of != . The bad choice of operators, together with other tricks is probably the main source of bugs in C programs. Didier ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
Re: [DNG] OT: some ancient programming language history
On Sun, 2015-07-26 at 23:58 +0200, Didier Kryn wrote: Ada is not an acronym, it's after the first name of the first person who wrote programs, the daughter of Byron, the english poet. Yes, I know. Ada is used in many places where human life is at stake: eg. planes, missiles, Eurocontrol (the european air cirulation regulation), the driver-less metro in Paris. The initial version was Ada83. There have been some revisions since. Add95 was a major one and the last is Ada2012. Yes. Allow me to rephrase. When I was taught Ada, it was assumed that Ada was used primarily by the US Department of Defense, who had a hand its creation. The affectation operator is := instead of = in C, and the comparison are = (instead of ==) and /= instead of != . The bad choice of operators, together with other tricks is probably the main source of bugs in C programs. I like the fact that Ada is very strict, because it forces new programmers to do things right. On the other hand, that comes at the cost of flexibility, which makes it useless for certain tasks. Since C predates Ada by at least a decade, I don't think C is the problem. I have never had a problem keeping ==, = or != straight. It's just my opinion, but there are at least a 2 dozen languages that use the same syntax. Programmers who spent a large part of their careers in low level or embedded have no problems with it that I can tell. I think the only ones who DO have that problem are programmers who learned things like Pascal or Ada first, along with the new kids who can't seem to program their way out of a paper bag without resorting to OOP. Example? Have a good laugh. I know I did. http://blog.pluralsight.com/give-me-those-old-time-programmers “These younger engineers can write a lot of sloppy code, and it doesn’t matter, but here, with very limited capacity, you have to be extremely precise and have a real strategy.” ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
[DNG] OT: some ancient programming language history
On Sun, Jul 26, 2015 at 04:52:10PM +0200, Didier Kryn wrote: Le 25/07/2015 20:55, Hendrik Boom a écrit : ... This really violates the standing principle of paying for only what you use. I encountered this principle long ago when I got involved in the design and implementation of Algol 68 -- they deliberately violated it with one feature -- they decided that everyone would pay the price of a procedure calling mechanism that supported recursion. Sometimes it is the right thing to do. The same decision was made by practically eveery language designed afterward. Not to say they didn't accidentally violate it a few times, of course. I'm talking five decades ago, back when people were inventing the language design principles we now take for granted. So you were involved in the design of Algol68! This was the first language I learned, in 1972-1973. The second of a great lineage which comprises Pascal and Ada. Kudos Hendrik! That's a pretty long carreer. Not the original 1968 version, but I was involved in the discussions leading to the revised report, as a post-doc under Barry Mailloux. I also wrote what's probably the most complete unfinished Algol 68 compiler in existence back then (source code still available if anyone wants to read it). I also had a long discussion with some of the guys in charge of the ADA project -- they really wanted the security that comes from completely automatic storage management but they couldn't afford to have their weapons systems stop for garbage collection, I told them exactly what the trade-offs were -- too what extent they could have their cake and eat it too. In the end they decided that they could afford neither the language complexity of the garbage-collector-free storage management schemes, nor the garbage collection delays. I'm not sure to what extent they ended up avoiding dynamically allocated storage in the first official language definition. -- hendrik ___ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
