| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315359 is a reply to message #315338] |
Fri, 01 April 2016 17:05   |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
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Senior Member |
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Scott Lurndal <scott@slp53.sl.home> wrote:
> Peter Flass <peter_flass@yahoo.com> writes:
>> Jon Elson <jmelson@wustl.edu> wrote:
>>> Charlie Gibbs wrote:
>>>
>>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>>
>>>> > In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> > sigma.research@gmail.com says...
>>>> >
>>>> >> Many might disagree, but APL is an
>>>> >> excellent language to start with. It was
>>>> >> the first language i sank my teeth into.
>>>> >> Easy to learn, but a lifetime to master.
>>>> >> There are a few free versions out there.
>>>> >
>>>> > Yep. Trouble is that if you learn to think in APL then other languages
>>>> > become frustrating.
>>>>
>>>> Once I learned to think in assembly language, any high-level language
>>>> became frustrating.
>>>>
>>>> Now I think in C - and high-level languages are still frustrating.
>>>>
>>> Gee, not really. It is a huge benefit to know what the machine code will
>>> look like in general when coding in HLLs. But, the minute detail of what's
>>> left in the carry bit from 5 instructions back, I really DON'T want to deal
>>> with. C can be a bit frustrating due to the crummy syntax, but it is kind
>>> of like English, the universal language. I did all the programming for my
>>> own use in Pascal for quite some years, and still think it is a pretty good
>>> language. it might even be making a comeback!
>>>
>>
>> You might convince me to take another look at Pascal. I know at least one
>> other guy who does good stuff with it. I looked at it years back when it
>> was a fad, but at that time the missing features and implementation
>> incompatibilities made it less than a good choice for me.
>
> VAX-11 Pascal was fully featured - sufficient to write
> efficient systems software.
>
>> In general I
>> prefer PL/I, but it's most useful for larger projects. I'd like something
>> like C was originally - a few instructions of overhead and otherwise just a
>> minimalist compilation of the C into machine code. Now there's way too
>> much cruft, although some compilers for imbedded systems probably do a good
>> job.
>
> When was the last time you used a C compiler? The quality of generated
> code from modern compilers (PCG, Intel C, GCC, Clang) is exemplary. Visual
> Studio lags, it is true.
I've used gcc. I was thinking of Aztec C for DOS (and probably
Borland,etc.), that had something like four instructions of overhead for a
program. Nowadays the startup calls tons of library code before the
program does anything, even if it just returns.
>
> http://www.pgroup.com/
>
--
Pete
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315360 is a reply to message #315358] |
Fri, 01 April 2016 17:05 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
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Senior Member |
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Gene Wirchenko <genew@telus.net> wrote:
> On Thu, 31 Mar 2016 07:37:18 +0100, Ahem A Rivet's Shot
> <steveo@eircom.net> wrote:
>
>> On 31 Mar 2016 03:10:59 -0300
>> Mike Spencer <mspencer@tallships.ca> wrote:
>>
>>>
>>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>>
>>>> Most programmers I have met in the last decade or so could do
>>>> with a grounding in basic computer science.
>>>
>>> It's worthy of note that early on, programmers were engineers,
>>> mathematicians, physical science types, musicians and heterogeneous
>>> eccentrics. A lot of the jargon emerged from those backgrounds.
>>>
>>> Twenty-five years ago, when I had occasion to work next to an
>>> about-graduate comp sci major at a university biz school, I was appalled
>>> to learn that he thought that if Unix ran multiple programs
>>> "simultaneously" that they were really executing their op codes at the
>>> same time. This was long before multi-CPU or multi-core machines were
>>> an article of commerce. I thought he was supposed to have spent the
>>> preceding 4 years getting "a grounding in basic computer science."
>>
>> That is alarming.
>
> Truly.
>
> I got my BCS in 2010. I remember one explanation of how the
> computer executes code that was simplified to the point of being very
> misleading. Many things that I learned in my teen years were not
> covered in the program. I am referring to useful things like how
> floating point arithmetic works!
>
> Sincerely,
>
> Gene Wirchenko
>
If you understand it, maybe you could explain it to me! (just kidding)
--
Pete
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315361 is a reply to message #315344] |
Fri, 01 April 2016 17:05 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
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Senior Member |
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Scott Lurndal <scott@slp53.sl.home> wrote:
> Bob Eager <news0006@eager.cx> writes:
>
>>
>> It may LOOK like it - but nothing like. The PDP-11 is moderately
>> orthogonal - the x86 isn't. PDP-11 instructions mostly work with any
>> source and destination - the x86 ones don't.
>
> The x86 instructions mostly work with any source and destination as well.
> This isn't 1980 anymore.
>
>>
>>>
>>> And here's arm aarch64:
>>>
>>> 0000000000401570 <register_tm_clones>:
>>> 401570: b0000081 adrp x1, 412000
>>> <__frame_dummy_init_array_entry>
>>> 401574: b0000080 adrp x0, 412000
>>> <__frame_dummy_init_array_entry>
>>> 401578: 910ae021 add x1, x1, #0x2b8 40157c:
>>> 910ae000 add x0, x0, #0x2b8 401580: 58000187
>>> ldr x7, 4015b0 <register_tm_clones+0x40> 401584: cb000021
>>> sub x1, x1, x0 401588: 9343fc21 asr x1, x1,
>>> #3 40158c: 8b41fc21 add x1, x1, x1, lsr #63 401590:
>>> 9341fc21 asr x1, x1, #1 401594: eb1f003f
>>> cmp x1, xzr 401598: fa5f10e4 ccmp x7, xzr, #0x4,
>>> ne 40159c: 54000060 b.eq 4015a8
>>> <register_tm_clones+0x38>
>>> 4015a0: d61f00e0 br x7 4015a4: d503201f
>>> nop 4015a8: d65f03c0 ret 4015ac: d503201f
>>> nop
>>>
>>> To me, the x86 is more readable. YMMV.
>>
>> It certainly does. And I have used a dozen different assembly languages,
>> at an absolute minimum.
>
> Too bad your posting client mangles the quoted article.
>
> I've programmed (for pay) in assembler on the PDP-8, PDP-11, Vax-11/780,
> Itel AS-6 (running MVS), Burroughs medium systems (as an operating
> system engineer), 6502, 68K, 88100, MIPS, Intel (386 to current Xeons) and ARM64 in
> the last 40 years.
>
> They all have their quirks. I was never fond of the 370 instruction
> set myself. I did quite like the VAX instruction set, I found MOVC5
> particularly useful having some characteristics in common with the Burroughs
> data movement instructions.
>
I liked the VAX too, but it always seemed to me that a large portion of the
instruction set would be unused by the average programmer.
--
Pete
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315365 is a reply to message #315325] |
Fri, 01 April 2016 18:41 |
Anonymous
Messages: 58
Registered: July 2012
Karma: 0
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Member |
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Stan Barr <plan.b@bluesomatic.org> wrote:
> On Thu, 31 Mar 2016 16:07:54 -0500, Jon Elson <jmelson@wustl.edu> wrote:
>> I did all the programming for my
>> own use in Pascal for quite some years, and still think it is a pretty good
>> language. it might even be making a comeback!
>
> I would prefer Modula-2, I did a lot of stuff in FST Modula back in
> the MSDOS days. Sort of Pascal redone right(er)
> Oberon is worh a look too, it follows on from Modula.
The natural follow on from Pascal is Ada, a gcc-supported language that
corrects all of Pascal's many mistakes. Modula and Oberon just continue
down the same misguided path of fetishizing ever-increasing
'simplicity'.
--
Bill Findlay
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315367 is a reply to message #315358] |
Fri, 01 April 2016 19:10 |
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Originally posted by: Bob Eager
On Fri, 01 Apr 2016 13:09:09 -0700, Gene Wirchenko wrote:
> On Thu, 31 Mar 2016 07:37:18 +0100, Ahem A Rivet's Shot
> <steveo@eircom.net> wrote:
>
>> On 31 Mar 2016 03:10:59 -0300 Mike Spencer <mspencer@tallships.ca>
>> wrote:
>>
>>
>>> Ahem A Rivet's Shot <steveo@eircom.net> writes:
>>>
>>>> Most programmers I have met in the last decade or so could do
>>>> with a grounding in basic computer science.
>>>
>>> It's worthy of note that early on, programmers were engineers,
>>> mathematicians, physical science types, musicians and heterogeneous
>>> eccentrics. A lot of the jargon emerged from those backgrounds.
>>>
>>> Twenty-five years ago, when I had occasion to work next to an
>>> about-graduate comp sci major at a university biz school, I was
>>> appalled to learn that he thought that if Unix ran multiple programs
>>> "simultaneously" that they were really executing their op codes at the
>>> same time. This was long before multi-CPU or multi-core machines were
>>> an article of commerce. I thought he was supposed to have spent the
>>> preceding 4 years getting "a grounding in basic computer science."
>>
>> That is alarming.
>
> Truly.
>
> I got my BCS in 2010. I remember one explanation of how the
> computer executes code that was simplified to the point of being very
> misleading. Many things that I learned in my teen years were not
> covered in the program. I am referring to useful things like how
> floating point arithmetic works!
Where I worked (until 3 months ago) we taught that in the very firstv
semester.
--
Using UNIX since v6 (1975)...
Use the BIG mirror service in the UK:
http://www.mirrorservice.org
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315368 is a reply to message #315361] |
Fri, 01 April 2016 19:11 |
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Originally posted by: Bob Eager
On Fri, 01 Apr 2016 17:05:02 -0400, Peter Flass wrote:
> Scott Lurndal <scott@slp53.sl.home> wrote:
>> Bob Eager <news0006@eager.cx> writes:
>>
>>
>>> It may LOOK like it - but nothing like. The PDP-11 is moderately
>>> orthogonal - the x86 isn't. PDP-11 instructions mostly work with any
>>> source and destination - the x86 ones don't.
>>
>> The x86 instructions mostly work with any source and destination as
>> well.
>> This isn't 1980 anymore.
>>
>>
>>>
>>>> And here's arm aarch64:
>>>>
>>>> 0000000000401570 <register_tm_clones>:
>>>> 401570: b0000081 adrp x1, 412000
>>>> <__frame_dummy_init_array_entry>
>>>> 401574: b0000080 adrp x0, 412000
>>>> <__frame_dummy_init_array_entry>
>>>> 401578: 910ae021 add x1, x1, #0x2b8 40157c: 910ae000
>>>> add x0, x0, #0x2b8 401580: 58000187 ldr x7,
>>>> 4015b0 <register_tm_clones+0x40> 401584: cb000021 sub x1,
>>>> x1, x0 401588: 9343fc21 asr x1, x1,
>>>> #3 40158c: 8b41fc21 add x1, x1, x1, lsr #63 401590:
>>>> 9341fc21 asr x1, x1, #1 401594: eb1f003f cmp x1,
>>>> xzr 401598: fa5f10e4 ccmp x7, xzr, #0x4,
>>>> ne 40159c: 54000060 b.eq 4015a8
>>>> <register_tm_clones+0x38>
>>>> 4015a0: d61f00e0 br x7 4015a4: d503201f nop
>>>> 4015a8: d65f03c0 ret 4015ac: d503201f nop
>>>>
>>>> To me, the x86 is more readable. YMMV.
>>>
>>> It certainly does. And I have used a dozen different assembly
>>> languages,
>>> at an absolute minimum.
>>
>> Too bad your posting client mangles the quoted article.
>>
>> I've programmed (for pay) in assembler on the PDP-8, PDP-11,
>> Vax-11/780,
>> Itel AS-6 (running MVS), Burroughs medium systems (as an operating
>> system engineer), 6502, 68K, 88100, MIPS, Intel (386 to current Xeons)
>> and ARM64 in the last 40 years.
>>
>> They all have their quirks. I was never fond of the 370 instruction
>> set myself. I did quite like the VAX instruction set, I found MOVC5
>> particularly useful having some characteristics in common with the
>> Burroughs data movement instructions.
>>
>>
> I liked the VAX too, but it always seemed to me that a large portion of
> the instruction set would be unused by the average programmer.
I agree. Even compiler writers found it hard (I wrote a VAX compiler)!
--
Using UNIX since v6 (1975)...
Use the BIG mirror service in the UK:
http://www.mirrorservice.org
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315372 is a reply to message #315179] |
Fri, 01 April 2016 21:12 |
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Originally posted by: J. Clarke
In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
says...
>
> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>
>> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>> says...
>>
>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>
>>>> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> sigma.research@gmail.com says...
>>>>
>>>> > Many might disagree, but APL is an
>>>> > excellent language to start with. It was
>>>> > the first language i sank my teeth into.
>>>> > Easy to learn, but a lifetime to master.
>>>> > There are a few free versions out there.
>>>>
>>>> Yep. Trouble is that if you learn to think in APL then other languages
>>>> become frustrating.
>>>
>>> Once I learned to think in assembly language, any high-level language
>>> became frustrating.
>>>
>>> Now I think in C - and high-level languages are still frustrating.
>>
>> Different kind of frustrating.
>>
>> In APL if you are using a loop you are probably doing something wrong.
>
> Not in my kind of applications. Are you saying that APL isn't suited to
> sequential processing of records in a file? (Database gurus notwithstanding,
> sequential processing is still the most efficient way to scan a million-record
> file.)
In APL you don't "scan records", you suck them all into an array and
then use the array operations.
Arrays contining a million records are well within the capabilities of
any modern APL system.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315375 is a reply to message #315372] |
Fri, 01 April 2016 21:29 |
Charlie Gibbs
Messages: 5313
Registered: January 2012
Karma: 0
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Senior Member |
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On 2016-04-02, J. Clarke <j.clarke.873638@gmail.com> wrote:
> In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
> says...
>>
>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>
>>> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>> says...
>>>
>>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>>
>>>> > In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> > sigma.research@gmail.com says...
>>>> >
>>>> >> Many might disagree, but APL is an
>>>> >> excellent language to start with. It was
>>>> >> the first language i sank my teeth into.
>>>> >> Easy to learn, but a lifetime to master.
>>>> >> There are a few free versions out there.
>>>> >
>>>> > Yep. Trouble is that if you learn to think in APL then other languages
>>>> > become frustrating.
>>>>
>>>> Once I learned to think in assembly language, any high-level language
>>>> became frustrating.
>>>>
>>>> Now I think in C - and high-level languages are still frustrating.
>>>
>>> Different kind of frustrating.
>>>
>>> In APL if you are using a loop you are probably doing something wrong.
>>
>> Not in my kind of applications. Are you saying that APL isn't
>> suited to sequential processing of records in a file? (Database
>> gurus notwithstanding, sequential processing is still the most
>> efficient way to scan a million-record file.)
>
> In APL you don't "scan records", you suck them all into an array and
> then use the array operations.
>
> Arrays contining a million records are well within the capabilities of
> any modern APL system.
Perhaps this is one of those cases where knowing how things work gets in
the way. I have images of madly thrashing swap disks, and the inability
to process the first record until you've read the millionth. I presume
that APL is somehow _very_ different.
--
/~\ cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ / I'm really at ac.dekanfrus if you read it the right way.
X Top-posted messages will probably be ignored. See RFC1855.
/ \ HTML will DEFINITELY be ignored. Join the ASCII ribbon campaign!
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315380 is a reply to message #314826] |
Sat, 02 April 2016 00:25 |
Anne & Lynn Wheel
Messages: 3156
Registered: January 2012
Karma: 0
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Senior Member |
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Dave Garland <dave.garland@wizinfo.com> writes:
> I don't know anything about APL (other than that it led to weird
> keyboards), but does that imply that the array must fit into memory?
cambridge science center
http://www.garlic.com/~lynn/subtopic.html#545tech
ported apl\360 to cp67/cms for cms\apl. As part of cms\apl, on of the
things done was api to system services like file i/o ... so it could
handle real-world applications ... like larger than workspace size ...
typically 16kbytes for apl\360.
Another thing that had to be done was rework garbage collection.
APL\360 started out with all space compacted at one end of workspace
....and then every assignment allocated new location ... until it reached
the other end of workspace ... in which it did garbage collected.
Wasn't big deal for apl\360 workspace which were swapped as single piece
of storage. Moving to cp67/cms with workspace in demand paged virtual
memory, this could mean rapidly touching 16mbytes and then
compacting/garbage collection ... which resulted in lots of page
thrashing. garbage collection got tuned to be triggered before touching
excessive amount of workspace.
The APL forces criticized science center for corrupting the purity of
APL with the way the system services API was implemented. Eventually
they come up with "shared variables" semantices as mechanism for
accessing system services (replacing the original cms\apl
implementation)
https://en.wikipedia.org/wiki/Shared_Variables
this then shows up in apl\cms that was done for vm370/cms.
past posts mentioning apl &/or HONE (worldwide online sales&marketing
system that had majority of applications implemented in apl
.... originally cp67/cms cms\apl ... and then moved to vm370/cms and
apl\cms).
--
virtualization experience starting Jan1968, online at home since Mar1970
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315383 is a reply to message #315334] |
Sat, 02 April 2016 01:32 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
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Senior Member |
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On Fri, 01 Apr 2016 13:01:54 GMT
scott@slp53.sl.home (Scott Lurndal) wrote:
>> Ahem A Rivet's Shot <steveo@eircom.net> wrote:
>>> Do systems architecture courses take advantage of this by
>>> getting students to compare the affect of different architectures on
>>> various workflows using instrumented emulations ? If not - why not ?
>
> We certainly do that when we design our processors. We heavily simulate
> any changes to the architecture with both industry standard workloads and
> custom workloads using sophisticated simulation and emulation techniques.
> This is true for both our MIPS and ARM64 based products.
I would expect that and I imagine it has been going on since it was
a much more expensive thing to do. I was thinking mainly in terms of using
the technique as a teaching aid.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315393 is a reply to message #315375] |
Sat, 02 April 2016 08:19 |
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Originally posted by: J. Clarke
In article <ndn79701ej@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
says...
>
> On 2016-04-02, J. Clarke <j.clarke.873638@gmail.com> wrote:
>
>> In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>> says...
>>>
>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>
>>>> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> says...
>>>>
>>>> > On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >
>>>> >> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> >> sigma.research@gmail.com says...
>>>> >>
>>>> >>> Many might disagree, but APL is an
>>>> >>> excellent language to start with. It was
>>>> >>> the first language i sank my teeth into.
>>>> >>> Easy to learn, but a lifetime to master.
>>>> >>> There are a few free versions out there.
>>>> >>
>>>> >> Yep. Trouble is that if you learn to think in APL then other languages
>>>> >> become frustrating.
>>>> >
>>>> > Once I learned to think in assembly language, any high-level language
>>>> > became frustrating.
>>>> >
>>>> > Now I think in C - and high-level languages are still frustrating.
>>>>
>>>> Different kind of frustrating.
>>>>
>>>> In APL if you are using a loop you are probably doing something wrong.
>>>
>>> Not in my kind of applications. Are you saying that APL isn't
>>> suited to sequential processing of records in a file? (Database
>>> gurus notwithstanding, sequential processing is still the most
>>> efficient way to scan a million-record file.)
>>
>> In APL you don't "scan records", you suck them all into an array and
>> then use the array operations.
>>
>> Arrays contining a million records are well within the capabilities of
>> any modern APL system.
>
> Perhaps this is one of those cases where knowing how things work gets in
> the way. I have images of madly thrashing swap disks, and the inability
> to process the first record until you've read the millionth. I presume
> that APL is somehow _very_ different.
If you're dealing with databases too large to comfortably fit in RAM
then APL is really the wrong tool to be using. It can do the "read a
record, process a record, write a record" kind of processing but to do
that you're pretty much turning into imitation Fortran, and it's not
really a very good imitation Fortran.
We use it as part of our test strategy--typically we set up APL to
generate datasets containing inputs and expected outputs, then feed
those inputs into the C or Fortran production code and determine whether
the outputs match. If not then we figure out why and what to do about
it.
Anyway, this is kind of apart from the point I was making. In APL you
have numerous condise operators that do complicated things to every
element of an array, even a multidimensional array. Mostly procedures
that are handled by looping in other languages are handled by array
operations in APL, and there's a temptation for inexperienced APL
programmers to write loops that replicate built in functionality.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315394 is a reply to message #314826] |
Sat, 02 April 2016 08:24 |
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Originally posted by: J. Clarke
In article <ndnfit$ma2$1@dont-email.me>, dave.garland@wizinfo.com
says...
>
> On 4/1/2016 8:12 PM, J. Clarke wrote:
>> In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>> says...
>>>
>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>
>>>> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> says...
>>>>
>>>> > On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >
>>>> >> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> >> sigma.research@gmail.com says...
>>>> >>
>>>> >>> Many might disagree, but APL is an
>>>> >>> excellent language to start with. It was
>>>> >>> the first language i sank my teeth into.
>>>> >>> Easy to learn, but a lifetime to master.
>>>> >>> There are a few free versions out there.
>>>> >>
>>>> >> Yep. Trouble is that if you learn to think in APL then other languages
>>>> >> become frustrating.
>>>> >
>>>> > Once I learned to think in assembly language, any high-level language
>>>> > became frustrating.
>>>> >
>>>> > Now I think in C - and high-level languages are still frustrating.
>>>>
>>>> Different kind of frustrating.
>>>>
>>>> In APL if you are using a loop you are probably doing something wrong.
>>>
>>> Not in my kind of applications. Are you saying that APL isn't suited to
>>> sequential processing of records in a file? (Database gurus notwithstanding,
>>> sequential processing is still the most efficient way to scan a million-record
>>> file.)
>>
>> In APL you don't "scan records", you suck them all into an array and
>> then use the array operations.
>>
>> Arrays contining a million records are well within the capabilities of
>> any modern APL system.
>>
> I don't know anything about APL (other than that it led to weird
> keyboards), but does that imply that the array must fit into memory?
If you're dealing with data too big to comfortably fit into memory, APL
is probably the wrong tool to be using. It can do one-record-at-a-time
processing but if that's what you're doing it doesn't bring anything to
the party.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315397 is a reply to message #315393] |
Sat, 02 April 2016 09:34 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
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On Sat, 2 Apr 2016 08:19:40 -0400
"J. Clarke" <j.clarke.873638@gmail.com> wrote:
> Anyway, this is kind of apart from the point I was making. In APL you
> have numerous condise operators that do complicated things to every
> element of an array, even a multidimensional array. Mostly procedures
> that are handled by looping in other languages are handled by array
> operations in APL, and there's a temptation for inexperienced APL
> programmers to write loops that replicate built in functionality.
I recall being taught about APL but not learning the language, the
example that started the lesson was a five character program to produce
primes up to a given number. IIRC it worked by generating a one dimensional
array with the values 1 to n in it, transposing and multiplying to get the
2D array of the products and finally filtering the original array to remove
everything present in the 2D array. The takeaway seemed to be that APL
allowed you to write amazingly compact programs and was really expressive
in array manipulation - but efficiency was going to require some attention
to achieve.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315398 is a reply to message #315393] |
Sat, 02 April 2016 11:18 |
Andrew Swallow
Messages: 1705
Registered: January 2012
Karma: 0
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On 02/04/2016 13:19, J. Clarke wrote:
> In article <ndn79701ej@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
> says...
>>
>> On 2016-04-02, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>
>>> In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>>> says...
>>>>
>>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>>
>>>> > In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> > says...
>>>> >
>>>> >> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >>
>>>> >>> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> >>> sigma.research@gmail.com says...
>>>> >>>
>>>> >>>> Many might disagree, but APL is an
>>>> >>>> excellent language to start with. It was
>>>> >>>> the first language i sank my teeth into.
>>>> >>>> Easy to learn, but a lifetime to master.
>>>> >>>> There are a few free versions out there.
>>>> >>>
>>>> >>> Yep. Trouble is that if you learn to think in APL then other languages
>>>> >>> become frustrating.
>>>> >>
>>>> >> Once I learned to think in assembly language, any high-level language
>>>> >> became frustrating.
>>>> >>
>>>> >> Now I think in C - and high-level languages are still frustrating.
>>>> >
>>>> > Different kind of frustrating.
>>>> >
>>>> > In APL if you are using a loop you are probably doing something wrong.
>>>>
>>>> Not in my kind of applications. Are you saying that APL isn't
>>>> suited to sequential processing of records in a file? (Database
>>>> gurus notwithstanding, sequential processing is still the most
>>>> efficient way to scan a million-record file.)
>>>
>>> In APL you don't "scan records", you suck them all into an array and
>>> then use the array operations.
>>>
>>> Arrays contining a million records are well within the capabilities of
>>> any modern APL system.
>>
>> Perhaps this is one of those cases where knowing how things work gets in
>> the way. I have images of madly thrashing swap disks, and the inability
>> to process the first record until you've read the millionth. I presume
>> that APL is somehow _very_ different.
>
> If you're dealing with databases too large to comfortably fit in RAM
> then APL is really the wrong tool to be using. It can do the "read a
> record, process a record, write a record" kind of processing but to do
> that you're pretty much turning into imitation Fortran, and it's not
> really a very good imitation Fortran.
>
> We use it as part of our test strategy--typically we set up APL to
> generate datasets containing inputs and expected outputs, then feed
> those inputs into the C or Fortran production code and determine whether
> the outputs match. If not then we figure out why and what to do about
> it.
>
> Anyway, this is kind of apart from the point I was making. In APL you
> have numerous condise operators that do complicated things to every
> element of an array, even a multidimensional array. Mostly procedures
> that are handled by looping in other languages are handled by array
> operations in APL, and there's a temptation for inexperienced APL
> programmers to write loops that replicate built in functionality.
>
APL needs to treat databases as a special type of array. What ever the
top level may be doing the underlying subroutines can only handle one
field at a time.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315400 is a reply to message #315398] |
Sat, 02 April 2016 12:20 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
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On Sat, 2 Apr 2016 16:18:54 +0100
Andrew Swallow <am.swallow@btopenworld.com> wrote:
> APL needs to treat databases as a special type of array. What ever the
> top level may be doing the underlying subroutines can only handle one
> field at a time.
Not so sure of that, AFAICS APL would lend itself well to being
implemented with something like CUDA on a modern graphics card with
massively parallel operations.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315406 is a reply to message #315225] |
Sat, 02 April 2016 15:31 |
hancock4
Messages: 6746
Registered: December 2011
Karma: 0
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On Thursday, March 31, 2016 at 2:41:56 AM UTC-4, Charlie Gibbs wrote:
> That's why, after three years getting "a grounding in basic computer
> science", I realized how little computer science had to do with the
> Real World - so I got a programming job and dropped out of school.
A good book on the history of programming discussed that issue.
Back in the 1960s and 1970s there was a serious shortage of
programmers. Colleges had compsci courses, but the training
was not what industry needed. Further, industry learned that
hiring a college compsci professor as a consultant had weaknesses,
as their approach could be very esoteric and not related to solving
the actual problem efficiently.
My college offered a course in APL, which was basically worthless.
But it did not offer anything in S/360 JCL or S/360 assembler,
which would've been helpful.
It is important to note that in the business world, many programmers
came up through the ranks of computer operators or tabulating
machine operators. Advanced tab machine operators, who knew how
to wire boards, already understood the basic concepts of information
processing for business. The earliest programs basically mimicked
a tabulating machine.
Also, in the 1970s, many community colleges began to offer courses
in programming, oriented toward practical skills.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315408 is a reply to message #315223] |
Sat, 02 April 2016 15:46 |
hancock4
Messages: 6746
Registered: December 2011
Karma: 0
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Senior Member |
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On Thursday, March 31, 2016 at 2:11:10 AM UTC-4, Mike Spencer wrote:
> Twenty-five years ago, when I had occasion to work next to an
> about-graduate comp sci major at a university biz school, I was appalled
> to learn that he thought that if Unix ran multiple programs
> "simultaneously" that they were really executing their op codes at the
> same time. This was long before multi-CPU or multi-core machines were
> an article of commerce. I thought he was supposed to have spent the
> preceding 4 years getting "a grounding in basic computer science."
If the student was supposed to have past training as a systems
programmer, then he probably should've had a better understanding
of the internals. However, if he was studying application development
(or perhaps something like database structures), then much of what
went on "under the hood" was transparent to the application person,
and by that point, justifiably so. (Note that some grad students
have their undergraduate degree in a totally different field, and
might not have the background*.)
I remember years ago when I took drivers' ed, there was a debate in
that field in how much mechanical knowledge students should have.
Yes, students should be able to change a flat and check the oil.
But should students be taught how to _change_ the oil? Should
they understand the _internals_ of an automatic transmission, or
just know when to use D/1/2 settings?
The point is, that when technology marches forward, it becomes
more and more specialized. Learning how to program and run a
1401 required a different approach than the later S/360. I don't
think 1401 sites had dedicated 'systems programmers' since there
wasn't an operating system to maintain, but larger S/360 sites
required such people to tune and optimize OS/360, CICS, and
maintain the systems programs.
Going further back, yes, tab machine operators knew how to both
wire a plugboard and fix minor hardware problems. Undoubtedly,
a few S/360 application programmers knew how to fix some stuff,
but I dare say almost all hardware issues were given to the C/E.
* See the book "Film School", about a guy who was a medical tech
getting his master's in film at USC. Interesting, but disturbing
book. The professors were quite prejudiced. Also, if the equipment
assigned to a student failed--as it often did due to age--the
student did not get any extension to finish their project.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315409 is a reply to message #315239] |
Sat, 02 April 2016 15:56 |
hancock4
Messages: 6746
Registered: December 2011
Karma: 0
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Senior Member |
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On Thursday, March 31, 2016 at 6:40:38 AM UTC-4, Bob Eager wrote:
> This is why we had a Year in Industry programme. Real experience in real
> jobs.
Such programs have mixed results. Some students do indeed get
excellent real-world experience. But often, there are more students
than jobs available, and some students end up on low-level jobs where
they don't learn very much. Working in a computer room mounting
tapes is good experience, but spending a whole work period doing so
is a waste of time. Likewise, working as a bookkeeper or receptionist
is good for about a week, but a waste of time for a compsci major.
> 100% graduate employment.
Yes, generally prior industry experience looks a lot better on a
resume than say a clerk in a clothing store or being a lifeguard
when a kid graduates college.
However, future opportunities depend on how well the graduate sells
him or herself. For a compsci to say merely "sold clothes" isn't
very impressive, but if the graduate is knowledgeable about the
computerized point-of-sale system* and can talk about that, he will
look better to a prospective employer.
*I should note that some employers emphatically do not like their
low level workers asking too many questions, especially about
sales or computer systems. They get paranoid about security.
Many employers expect their low level people to do their specific
job and only their specific job. Unfortunately, kids who end up
in that kind of job learn little and have nothing to show for it.
If at all possible, kids should avoid that situation. But, as said,
sometimes co-op jobs are hard to find.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315411 is a reply to message #315306] |
Sat, 02 April 2016 16:04 |
hancock4
Messages: 6746
Registered: December 2011
Karma: 0
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Senior Member |
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On Thursday, March 31, 2016 at 5:32:35 PM UTC-4, ma...@mail.com wrote:
> I would challenge anyone to find a good book on BASIC in the shops nowadays.
BASIC now has various versions--Visual Basic (still in use, AFAIK),
and the other BASIC, which in turn had several versions.
I'm not even sure modern computers will even run old BASIC (e.g.
QBASIC from DOS 5.0 or GW-BASIC), since the upgrade in bitsize
requirements.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315414 is a reply to message #315336] |
Sat, 02 April 2016 16:06 |
hancock4
Messages: 6746
Registered: December 2011
Karma: 0
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Senior Member |
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On Friday, April 1, 2016 at 9:04:56 AM UTC-4, Scott Lurndal wrote:
> As for ED/EDMK (or EDT in Burroughs mainframes), why include all that
> in the hardware (with the associated area, verification and power
> costs) when a well-tuned software version performs almost as well
> and is much more flexible?
Why did IBM wait so long to add square-root as an assembler
command in the mainframe? Even business applications use it.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315415 is a reply to message #315397] |
Sat, 02 April 2016 16:10 |
hancock4
Messages: 6746
Registered: December 2011
Karma: 0
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Senior Member |
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On Saturday, April 2, 2016 at 10:00:02 AM UTC-4, Ahem A Rivet's Shot wrote:
> I recall being taught about APL but not learning the language, the
> example that started the lesson was a five character program to produce
> primes up to a given number. IIRC it worked by generating a one dimensional
> array with the values 1 to n in it, transposing and multiplying to get the
> 2D array of the products and finally filtering the original array to remove
> everything present in the 2D array. The takeaway seemed to be that APL
> allowed you to write amazingly compact programs and was really expressive
> in array manipulation - but efficiency was going to require some attention
> to achieve.
In some older works on bitsavers, there are case studies in which
the process utilizes extensive matrix arithmetic. Presumably,
APL would be good for something like that.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315418 is a reply to message #315406] |
Sat, 02 April 2016 16:38 |
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Originally posted by: J. Clarke
In article <254ce0f3-37d6-434d-ac5b-082c2dddcecd@googlegroups.com>,
hancock4@bbs.cpcn.com says...
>
> On Thursday, March 31, 2016 at 2:41:56 AM UTC-4, Charlie Gibbs wrote:
>
>> That's why, after three years getting "a grounding in basic computer
>> science", I realized how little computer science had to do with the
>> Real World - so I got a programming job and dropped out of school.
>
> A good book on the history of programming discussed that issue.
> Back in the 1960s and 1970s there was a serious shortage of
> programmers. Colleges had compsci courses, but the training
> was not what industry needed. Further, industry learned that
> hiring a college compsci professor as a consultant had weaknesses,
> as their approach could be very esoteric and not related to solving
> the actual problem efficiently.
>
> My college offered a course in APL, which was basically worthless.
For certain values. I got my current job mostly on the basis of such a
course taken 40 years ago, and dinking around with it since. If you
wanted to go into quantitative work it could be a major door opener.
STSC was pushing it hard then--they subsidized its use at many
universities and provided "circuit riders" whose job was near as I could
tell mostly to encourage its use.
> But it did not offer anything in S/360 JCL or S/360 assembler,
> which would've been helpful.
We also got 360 Assembler. No JCL though.
> It is important to note that in the business world, many programmers
> came up through the ranks of computer operators or tabulating
> machine operators. Advanced tab machine operators, who knew how
> to wire boards, already understood the basic concepts of information
> processing for business. The earliest programs basically mimicked
> a tabulating machine.
>
> Also, in the 1970s, many community colleges began to offer courses
> in programming, oriented toward practical skills.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315420 is a reply to message #315398] |
Sat, 02 April 2016 16:49 |
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Originally posted by: J. Clarke
In article <OIidnSNnI_1Vf2LLnZ2dnUU78UfNnZ2d@giganews.com>,
am.swallow@btopenworld.com says...
>
> On 02/04/2016 13:19, J. Clarke wrote:
>> In article <ndn79701ej@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>> says...
>>>
>>> On 2016-04-02, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>
>>>> In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> says...
>>>> >
>>>> > On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >
>>>> >> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> >> says...
>>>> >>
>>>> >>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >>>
>>>> >>>> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> >>>> sigma.research@gmail.com says...
>>>> >>>>
>>>> >>>>> Many might disagree, but APL is an
>>>> >>>>> excellent language to start with. It was
>>>> >>>>> the first language i sank my teeth into.
>>>> >>>>> Easy to learn, but a lifetime to master.
>>>> >>>>> There are a few free versions out there.
>>>> >>>>
>>>> >>>> Yep. Trouble is that if you learn to think in APL then other languages
>>>> >>>> become frustrating.
>>>> >>>
>>>> >>> Once I learned to think in assembly language, any high-level language
>>>> >>> became frustrating.
>>>> >>>
>>>> >>> Now I think in C - and high-level languages are still frustrating.
>>>> >>
>>>> >> Different kind of frustrating.
>>>> >>
>>>> >> In APL if you are using a loop you are probably doing something wrong.
>>>> >
>>>> > Not in my kind of applications. Are you saying that APL isn't
>>>> > suited to sequential processing of records in a file? (Database
>>>> > gurus notwithstanding, sequential processing is still the most
>>>> > efficient way to scan a million-record file.)
>>>>
>>>> In APL you don't "scan records", you suck them all into an array and
>>>> then use the array operations.
>>>>
>>>> Arrays contining a million records are well within the capabilities of
>>>> any modern APL system.
>>>
>>> Perhaps this is one of those cases where knowing how things work gets in
>>> the way. I have images of madly thrashing swap disks, and the inability
>>> to process the first record until you've read the millionth. I presume
>>> that APL is somehow _very_ different.
>>
>> If you're dealing with databases too large to comfortably fit in RAM
>> then APL is really the wrong tool to be using. It can do the "read a
>> record, process a record, write a record" kind of processing but to do
>> that you're pretty much turning into imitation Fortran, and it's not
>> really a very good imitation Fortran.
>>
>> We use it as part of our test strategy--typically we set up APL to
>> generate datasets containing inputs and expected outputs, then feed
>> those inputs into the C or Fortran production code and determine whether
>> the outputs match. If not then we figure out why and what to do about
>> it.
>>
>> Anyway, this is kind of apart from the point I was making. In APL you
>> have numerous condise operators that do complicated things to every
>> element of an array, even a multidimensional array. Mostly procedures
>> that are handled by looping in other languages are handled by array
>> operations in APL, and there's a temptation for inexperienced APL
>> programmers to write loops that replicate built in functionality.
>>
>
> APL needs to treat databases as a special type of array. What ever the
> top level may be doing the underlying subroutines can only handle one
> field at a time.
Maybe, maybe not. Modern hardware certainly has a good bit of parallel
processing capability--to what extent modern APLs take advantage of it I
have no idea but it certainly lends itself to parallization.
APL doesn't have special kinds of arrays. It just has arrays.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315421 is a reply to message #315409] |
Sat, 02 April 2016 17:14 |
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Originally posted by: Bob Eager
On Sat, 02 Apr 2016 12:56:22 -0700, hancock4 wrote:
> On Thursday, March 31, 2016 at 6:40:38 AM UTC-4, Bob Eager wrote:
>
>> This is why we had a Year in Industry programme. Real experience in
>> real jobs.
>
> Such programs have mixed results. Some students do indeed get excellent
> real-world experience. But often, there are more students than jobs
> available, and some students end up on low-level jobs where they don't
> learn very much. Working in a computer room mounting tapes is good
> experience, but spending a whole work period doing so is a waste of
> time. Likewise, working as a bookkeeper or receptionist is good for
> about a week, but a waste of time for a compsci major.
That depends on the quality of the placement operation. It was my job to
moderate the results, and after the first couple of years we had weeded
out such employers.
Current placements run at about 80% of our total intake, with the rest
not wanting a placement.
>
>
>> 100% graduate employment.
>
> Yes, generally prior industry experience looks a lot better on a resume
> than say a clerk in a clothing store or being a lifeguard when a kid
> graduates college.
>
> However, future opportunities depend on how well the graduate sells him
> or herself. For a compsci to say merely "sold clothes" isn't very
> impressive, but if the graduate is knowledgeable about the computerized
> point-of-sale system* and can talk about that, he will look better to a
> prospective employer.
>
>
> *I should note that some employers emphatically do not like their low
> level workers asking too many questions, especially about sales or
> computer systems. They get paranoid about security.
> Many employers expect their low level people to do their specific job
> and only their specific job. Unfortunately, kids who end up in that
> kind of job learn little and have nothing to show for it.
> If at all possible, kids should avoid that situation. But, as said,
> sometimes co-op jobs are hard to find.
--
Using UNIX since v6 (1975)...
Use the BIG mirror service in the UK:
http://www.mirrorservice.org
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315422 is a reply to message #315415] |
Sat, 02 April 2016 17:00 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
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Senior Member |
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On Sat, 2 Apr 2016 13:10:28 -0700 (PDT)
hancock4@bbs.cpcn.com wrote:
> On Saturday, April 2, 2016 at 10:00:02 AM UTC-4, Ahem A Rivet's Shot
> wrote:
>
>> I recall being taught about APL but not learning the language,
>> the example that started the lesson was a five character program to
>> produce primes up to a given number. IIRC it worked by generating a one
>> dimensional array with the values 1 to n in it, transposing and
>> multiplying to get the 2D array of the products and finally filtering
>> the original array to remove everything present in the 2D array. The
>> takeaway seemed to be that APL allowed you to write amazingly compact
>> programs and was really expressive in array manipulation - but
>> efficiency was going to require some attention to achieve.
>
> In some older works on bitsavers, there are case studies in which
> the process utilizes extensive matrix arithmetic. Presumably,
> APL would be good for something like that.
My understanding is that this sort of thing is exactly what APL was
designed for.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315427 is a reply to message #315406] |
Sat, 02 April 2016 20:09 |
Peter Flass
Messages: 8375
Registered: December 2011
Karma: 0
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Senior Member |
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<hancock4@bbs.cpcn.com> wrote:
> On Thursday, March 31, 2016 at 2:41:56 AM UTC-4, Charlie Gibbs wrote:
>
>> That's why, after three years getting "a grounding in basic computer
>> science", I realized how little computer science had to do with the
>> Real World - so I got a programming job and dropped out of school.
>
> A good book on the history of programming discussed that issue.
> Back in the 1960s and 1970s there was a serious shortage of
> programmers. Colleges had compsci courses, but the training
> was not what industry needed.
I went the other way - I worked in the "real world" for a few years and
then got a CS degree part time (and paid for :-) A lot of what I learned
was useful, and I still use some of that knowledge.
Further, industry learned that
> hiring a college compsci professor as a consultant had weaknesses,
> as their approach could be very esoteric and not related to solving
> the actual problem efficiently.
>
> My college offered a course in APL, which was basically worthless.
That depends. If you're doing analysis it would be useful.
> But it did not offer anything in S/360 JCL or S/360 assembler,
> which would've been helpful.
Our local community colleges offered this at the time, plus courses in
CICS. (as you mention below) Most of these graduates got god jobs after
graduation.
>
> It is important to note that in the business world, many programmers
> came up through the ranks of computer operators or tabulating
> machine operators.
Even back in the mid 60s we looked on these as the "old guys", who didn't
understand "modern" 360s or "current" languages like COBOL.
Advanced tab machine operators, who knew how
> to wire boards, already understood the basic concepts of information
> processing for business. The earliest programs basically mimicked
> a tabulating machine.
>
> Also, in the 1970s, many community colleges began to offer courses
> in programming, oriented toward practical skills.
>
>
--
Pete
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315430 is a reply to message #315420] |
Sat, 02 April 2016 19:52 |
Andrew Swallow
Messages: 1705
Registered: January 2012
Karma: 0
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Senior Member |
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On 02/04/2016 21:49, J. Clarke wrote:
> In article <OIidnSNnI_1Vf2LLnZ2dnUU78UfNnZ2d@giganews.com>,
> am.swallow@btopenworld.com says...
>>
>> On 02/04/2016 13:19, J. Clarke wrote:
>>> In article <ndn79701ej@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>>> says...
>>>>
>>>> On 2016-04-02, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>>
>>>> > In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> > says...
>>>> >>
>>>> >> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >>
>>>> >>> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> >>> says...
>>>> >>>
>>>> >>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >>>>
>>>> >>>>> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> >>>>> sigma.research@gmail.com says...
>>>> >>>>>
>>>> >>>>>> Many might disagree, but APL is an
>>>> >>>>>> excellent language to start with. It was
>>>> >>>>>> the first language i sank my teeth into.
>>>> >>>>>> Easy to learn, but a lifetime to master.
>>>> >>>>>> There are a few free versions out there.
>>>> >>>>>
>>>> >>>>> Yep. Trouble is that if you learn to think in APL then other languages
>>>> >>>>> become frustrating.
>>>> >>>>
>>>> >>>> Once I learned to think in assembly language, any high-level language
>>>> >>>> became frustrating.
>>>> >>>>
>>>> >>>> Now I think in C - and high-level languages are still frustrating.
>>>> >>>
>>>> >>> Different kind of frustrating.
>>>> >>>
>>>> >>> In APL if you are using a loop you are probably doing something wrong.
>>>> >>
>>>> >> Not in my kind of applications. Are you saying that APL isn't
>>>> >> suited to sequential processing of records in a file? (Database
>>>> >> gurus notwithstanding, sequential processing is still the most
>>>> >> efficient way to scan a million-record file.)
>>>> >
>>>> > In APL you don't "scan records", you suck them all into an array and
>>>> > then use the array operations.
>>>> >
>>>> > Arrays contining a million records are well within the capabilities of
>>>> > any modern APL system.
>>>>
>>>> Perhaps this is one of those cases where knowing how things work gets in
>>>> the way. I have images of madly thrashing swap disks, and the inability
>>>> to process the first record until you've read the millionth. I presume
>>>> that APL is somehow _very_ different.
>>>
>>> If you're dealing with databases too large to comfortably fit in RAM
>>> then APL is really the wrong tool to be using. It can do the "read a
>>> record, process a record, write a record" kind of processing but to do
>>> that you're pretty much turning into imitation Fortran, and it's not
>>> really a very good imitation Fortran.
>>>
>>> We use it as part of our test strategy--typically we set up APL to
>>> generate datasets containing inputs and expected outputs, then feed
>>> those inputs into the C or Fortran production code and determine whether
>>> the outputs match. If not then we figure out why and what to do about
>>> it.
>>>
>>> Anyway, this is kind of apart from the point I was making. In APL you
>>> have numerous condise operators that do complicated things to every
>>> element of an array, even a multidimensional array. Mostly procedures
>>> that are handled by looping in other languages are handled by array
>>> operations in APL, and there's a temptation for inexperienced APL
>>> programmers to write loops that replicate built in functionality.
>>>
>>
>> APL needs to treat databases as a special type of array. What ever the
>> top level may be doing the underlying subroutines can only handle one
>> field at a time.
>
> Maybe, maybe not. Modern hardware certainly has a good bit of parallel
> processing capability--to what extent modern APLs take advantage of it I
> have no idea but it certainly lends itself to parallization.
>
> APL doesn't have special kinds of arrays. It just has arrays.
>
>
Which is why it cannot handle databases.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315431 is a reply to message #315422] |
Sat, 02 April 2016 20:35 |
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Originally posted by: J. Clarke
In article <20160402220014.f32eb4867c8578d9345b9806@eircom.net>,
steveo@eircom.net says...
>
> On Sat, 2 Apr 2016 13:10:28 -0700 (PDT)
> hancock4@bbs.cpcn.com wrote:
>
>> On Saturday, April 2, 2016 at 10:00:02 AM UTC-4, Ahem A Rivet's Shot
>> wrote:
>>
>>> I recall being taught about APL but not learning the language,
>>> the example that started the lesson was a five character program to
>>> produce primes up to a given number. IIRC it worked by generating a one
>>> dimensional array with the values 1 to n in it, transposing and
>>> multiplying to get the 2D array of the products and finally filtering
>>> the original array to remove everything present in the 2D array. The
>>> takeaway seemed to be that APL allowed you to write amazingly compact
>>> programs and was really expressive in array manipulation - but
>>> efficiency was going to require some attention to achieve.
>>
>> In some older works on bitsavers, there are case studies in which
>> the process utilizes extensive matrix arithmetic. Presumably,
>> APL would be good for something like that.
>
> My understanding is that this sort of thing is exactly what APL was
> designed for.
It was intended for use as an alternative mathematical notation--pretty
much an exercise, then I understand that it was realized that it could
be implemented as a kind of very high level pseudocode for for both
programming and hardware conceptualization. Then it was actually
implemented.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315432 is a reply to message #315430] |
Sat, 02 April 2016 20:37 |
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Originally posted by: J. Clarke
In article <B-2dne22l8iCxp3KnZ2dnUU78LOdnZ2d@giganews.com>,
am.swallow@btopenworld.com says...
>
> On 02/04/2016 21:49, J. Clarke wrote:
>> In article <OIidnSNnI_1Vf2LLnZ2dnUU78UfNnZ2d@giganews.com>,
>> am.swallow@btopenworld.com says...
>>>
>>> On 02/04/2016 13:19, J. Clarke wrote:
>>>> In article <ndn79701ej@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> says...
>>>> >
>>>> > On 2016-04-02, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >
>>>> >> In article <ndgv2u048b@news6.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> >> says...
>>>> >>>
>>>> >>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >>>
>>>> >>>> In article <ndfnam014op@news4.newsguy.com>, cgibbs@kltpzyxm.invalid
>>>> >>>> says...
>>>> >>>>
>>>> >>>>> On 2016-03-30, J. Clarke <j.clarke.873638@gmail.com> wrote:
>>>> >>>>>
>>>> >>>>>> In article <fd704521-012a-4bdc-acec-c83269e46c4e@googlegroups.com>,
>>>> >>>>>> sigma.research@gmail.com says...
>>>> >>>>>>
>>>> >>>>>>> Many might disagree, but APL is an
>>>> >>>>>>> excellent language to start with. It was
>>>> >>>>>>> the first language i sank my teeth into.
>>>> >>>>>>> Easy to learn, but a lifetime to master.
>>>> >>>>>>> There are a few free versions out there.
>>>> >>>>>>
>>>> >>>>>> Yep. Trouble is that if you learn to think in APL then other languages
>>>> >>>>>> become frustrating.
>>>> >>>>>
>>>> >>>>> Once I learned to think in assembly language, any high-level language
>>>> >>>>> became frustrating.
>>>> >>>>>
>>>> >>>>> Now I think in C - and high-level languages are still frustrating.
>>>> >>>>
>>>> >>>> Different kind of frustrating.
>>>> >>>>
>>>> >>>> In APL if you are using a loop you are probably doing something wrong.
>>>> >>>
>>>> >>> Not in my kind of applications. Are you saying that APL isn't
>>>> >>> suited to sequential processing of records in a file? (Database
>>>> >>> gurus notwithstanding, sequential processing is still the most
>>>> >>> efficient way to scan a million-record file.)
>>>> >>
>>>> >> In APL you don't "scan records", you suck them all into an array and
>>>> >> then use the array operations.
>>>> >>
>>>> >> Arrays contining a million records are well within the capabilities of
>>>> >> any modern APL system.
>>>> >
>>>> > Perhaps this is one of those cases where knowing how things work gets in
>>>> > the way. I have images of madly thrashing swap disks, and the inability
>>>> > to process the first record until you've read the millionth. I presume
>>>> > that APL is somehow _very_ different.
>>>>
>>>> If you're dealing with databases too large to comfortably fit in RAM
>>>> then APL is really the wrong tool to be using. It can do the "read a
>>>> record, process a record, write a record" kind of processing but to do
>>>> that you're pretty much turning into imitation Fortran, and it's not
>>>> really a very good imitation Fortran.
>>>>
>>>> We use it as part of our test strategy--typically we set up APL to
>>>> generate datasets containing inputs and expected outputs, then feed
>>>> those inputs into the C or Fortran production code and determine whether
>>>> the outputs match. If not then we figure out why and what to do about
>>>> it.
>>>>
>>>> Anyway, this is kind of apart from the point I was making. In APL you
>>>> have numerous condise operators that do complicated things to every
>>>> element of an array, even a multidimensional array. Mostly procedures
>>>> that are handled by looping in other languages are handled by array
>>>> operations in APL, and there's a temptation for inexperienced APL
>>>> programmers to write loops that replicate built in functionality.
>>>>
>>>
>>> APL needs to treat databases as a special type of array. What ever the
>>> top level may be doing the underlying subroutines can only handle one
>>> field at a time.
>>
>> Maybe, maybe not. Modern hardware certainly has a good bit of parallel
>> processing capability--to what extent modern APLs take advantage of it I
>> have no idea but it certainly lends itself to parallization.
>>
>> APL doesn't have special kinds of arrays. It just has arrays.
>>
>>
> Which is why it cannot handle databases.
So how many lines of APL code have you been paid to write?
There are reasons that APL is a poor choice for database programming,
but the one you state is not one of them.
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315433 is a reply to message #315414] |
Sat, 02 April 2016 21:25 |
Dan Espen
Messages: 3867
Registered: January 2012
Karma: 0
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Senior Member |
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hancock4@bbs.cpcn.com writes:
> On Friday, April 1, 2016 at 9:04:56 AM UTC-4, Scott Lurndal wrote:
>
>> As for ED/EDMK (or EDT in Burroughs mainframes), why include all that
>> in the hardware (with the associated area, verification and power
>> costs) when a well-tuned software version performs almost as well
>> and is much more flexible?
>
> Why did IBM wait so long to add square-root as an assembler
> command in the mainframe? Even business applications use it.
They were waiting for me to see it needed somewhere.
Too late now.
They implemented the instruction before I needed it
and I'm not looking any more.
--
Dan Espen
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315472 is a reply to message #315414] |
Sun, 03 April 2016 12:52 |
Walter Bushell
Messages: 1834
Registered: December 2011
Karma: 0
|
Senior Member |
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In article <3e3b0585-0d6c-4a20-b1ef-3c7bbd6d8da7@googlegroups.com>,
hancock4@bbs.cpcn.com wrote:
> On Friday, April 1, 2016 at 9:04:56 AM UTC-4, Scott Lurndal wrote:
>
>> As for ED/EDMK (or EDT in Burroughs mainframes), why include all that
>> in the hardware (with the associated area, verification and power
>> costs) when a well-tuned software version performs almost as well
>> and is much more flexible?
>
> Why did IBM wait so long to add square-root as an assembler
> command in the mainframe? Even business applications use it.
Fast to implement in software, if you have multiply and divide
ops.
--
To terrify children with the image of hell,
to consider women an inferior creation is that good for the world?
Christopher Hitchens
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315474 is a reply to message #315306] |
Sun, 03 April 2016 12:57 |
Walter Bushell
Messages: 1834
Registered: December 2011
Karma: 0
|
Senior Member |
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In article <slrnnfr5qt.18t.mausg@Smaus.org>, mausg@mail.com wrote:
> On 2016-03-30, Morten Reistad <first@Last.name.invalid> wrote:
>> In article
>> <950348948.481046768.067116.peter_flass-yahoo.com@news.eternal-september.org
>>> ,
>> Peter Flass <peter_flass@yahoo.com> wrote:
>>> Scott Lurndal <scott@slp53.sl.home> wrote:
>>>> jmfbahciv <See.above@aol.com> writes:
>>>> > Mike Spencer wrote:
>>>> >>
>>>
>>> I wouldn't recommend x86 for anyone just trying to learn computers at the
>>> machine language level. I don't know ARM, that might be better, but most
>>> modern architectures are much too complex. I don't care much for the PDP8,
>>> but the -11 might not be a bad place to start.
>>
>> ARM, unoptimised, is a lot easier to read than x86, almost to the level
>> of the pdp10. The problem comes with the thumb/thumb2 "compressed"
>> instructions,
>> which is essential to all modern arm optimisation.
>>
>>> OTOH, OP said the person wanted to learn programming, so s/he should
>>> probably start with an HLL. That's one thing to be said for BASIC, the "B"
>>> stands for "beginner's" for a reason. You can learn most of the basics of
>>> programming without all the complexity. Interpreters are available for
>>> free for most systems.
>>
>> Dabble around in basic, yes. Or even a *n*x shell. But do go for a heavily
>> structured language too.
>
> I would challenge anyone to find a good book on BASIC in the shops nowadays.
>
> Ruby, in a uncomplex fashion, is fairly easy.
>
> (Why does every new book on Python have the examples in Ipython?.
> Surely the best ways to learn is to write a program, find out where
> the faults are, and edit them).
>
> Best of all is to an hear an un-english-speaker trying to learn it, and
> realizing how complex it is.
What is Ipython?
--
To terrify children with the image of hell,
to consider women an inferior creation is that good for the world?
Christopher Hitchens
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315475 is a reply to message #315079] |
Sun, 03 April 2016 13:02 |
Walter Bushell
Messages: 1834
Registered: December 2011
Karma: 0
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Senior Member |
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In article <20160329134207.4d7d77389889326e422c0e55@eircom.net>,
Ahem A Rivet's Shot <steveo@eircom.net> wrote:
> On 29 Mar 2016 12:25:57 GMT
> Bob Eager <news0006@eager.cx> wrote:
>
>> On Tue, 29 Mar 2016 11:50:42 +0100, Ahem A Rivet's Shot wrote:
>>
>>> I'd say that depends on whether you want to learn to write
>> programs
>>> or to understand algorithms. Knuth is an amazingly comprehensive
>>> academic study and catalogue of algorithms, a truly wonderful reference.
>>> It is indeed not a tutorial for beginners (or indeed anybody).
>>
>> I too thought the OP sounded like a beginner.
>
> I rather suspect so, but I'd hate to discourage anyone from
> studying algorithms - far too few ever do.
>
>> I find Knuth useful but I've been a computer scientist for nearly 40
>> years. It's right here on the shelf!
>
> The real hope is that the OP will find it fascinating and go on to
> create algorithms of wonderous subtlety.
>
> The one problem with Knuth is that you've probably had it on your
> shelf for those nearly 40 years - there have been a few new twists on
> algorithms and data structures in the meantime, and rather less need for
> sort/merge that won't fit in online storage than there used to be.
Only a few people _need_ to do a sort/merge these days, the canned ones
are probably better not to mention better tested.
--
To terrify children with the image of hell,
to consider women an inferior creation is that good for the world?
Christopher Hitchens
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315485 is a reply to message #315475] |
Sun, 03 April 2016 13:42 |
Ahem A Rivet's Shot
Messages: 4843
Registered: January 2012
Karma: 0
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Senior Member |
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On Sun, 03 Apr 2016 13:02:37 -0400
Walter Bushell <proto@panix.com> wrote:
> In article <20160329134207.4d7d77389889326e422c0e55@eircom.net>,
> Ahem A Rivet's Shot <steveo@eircom.net> wrote:
>
>> The one problem with Knuth is that you've probably had it on
>> your shelf for those nearly 40 years - there have been a few new twists
>> on algorithms and data structures in the meantime, and rather less need
>> for sort/merge that won't fit in online storage than there used to be.
>
> Only a few people _need_ to do a sort/merge these days, the canned ones
> are probably better not to mention better tested.
Even fewer need to consider the cases where the canned ones are not
suited - the we have the data on n tapes and we have m tape drives how do
we sort it and minimise the tape swaps! These days if the data won't fit in
RAM it's bigger than most datasets when those chapters were written.
--
Steve O'Hara-Smith | Directable Mirror Arrays
C:>WIN | A better way to focus the sun
The computer obeys and wins. | licences available see
You lose and Bill collects. | http://www.sohara.org/
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| Re: Which Books Can You Recommend For Learning Computer Programming? [message #315498 is a reply to message #315484] |
Sun, 03 April 2016 14:39 |
Morten Reistad
Messages: 2108
Registered: December 2011
Karma: 0
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Senior Member |
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In article <dmd3u5F6vjlU1@mid.individual.net>,
Thomas Johns <TJzz@gmail.com> wrote:
>
>
> "Walter Bushell" <proto@panix.com> wrote in message
> news:proto-8C4477.12561503042016@news.panix.com...
>> In article <8uhtsc-6b1.ln1@sambook.reistad.name>,
>> Morten Reistad <first@Last.name.invalid> wrote:
>>
>>> In article
>>> <950348948.481046768.067116.peter_flass-yahoo.com@news.eternal-september.org>,
>>> Peter Flass <peter_flass@yahoo.com> wrote:
>>>
>>>> OTOH, OP said the person wanted to learn programming, so s/he should
>>>> probably start with an HLL. That's one thing to be said for BASIC, the
>>>> "B"
>>>> stands for "beginner's" for a reason. You can learn most of the basics
>>>> of
>>>> programming without all the complexity. Interpreters are available for
>>>> free for most systems.
>>>
>>> Dabble around in basic, yes. Or even a *n*x shell. But do go for a
>>> heavily
>>> structured language too.
>
>> Some "Basics" are structured.
>
>> There must be structured Fortrans than
>> allow recursion, these days.
>
> There have been structured Fortrans for 40 years now, most obviously with
> Ratfor.
> https://en.wikipedia.org/wiki/Ratfor
At one point in the journey towards programming you will probably
benefit from a little structured coersion from the language. Pascal
does this well. After writing a few thousand lines of code you will
get the gist of it, of you ever will. So take an excursion into
this land, reasonably early in your quest.
-- mrr
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