I get The reference info was not found in the current environment when I try to do a make on the Adam Chlipala Certified Programming with Dependent Types download software cpdt bundle. The file is LogicProg.v line 155. There were other problems before this (see here). And lots of errors where I had to change [ ] to { } around stuff. But this seems to be the last bug.
The surrounding text mentions that info is no longer available:
with the info tactical. (This tactical is not available in Coq 8.4 as of this writing, but I hope it reappears soon. The special case info_auto tactic is provided as a chatty replacement for auto.)
It was partially replaced by the command Info 1:
(* Instead of: info auto 6 *)
Info 1 auto 6.
Another alternative is to just remove info and skip mentions of it.
Related
I wanted to see how magics are defined from some sample source but did not find info from web.
Moreover, where should the IPython extensions reside?
To understand how to deploy your custom magic you need to read 2 sectinos of IPython's documentation:
How to write your own magic
How to write an extension
Then you will see that generally a magic is simply a class that define magics methods in Python module.
Here is for example a self contained IPython magic as an extension, the code is not the best, but just to show you it can be small.
As to where the IPython's builtin's one are defined, they all are in this folder, though I would not recommend to take them as an example, as there is a lot of historical baggage and can be quite complex.
A more recent full example and will appear in the docs once next version of IPython is released.
As far as I know and I have read in linker documentation there are 5 output section types: NOLOAD, DSECT, COPY, INFO, OVERLAY but only 2 of them are explained: NOLOAD and OVERLAY. COPY, INFO and DSECT are not explained and everywhere in the internet I can see the same 2 explained and 3 left without a word. Anyone would be so kind to explain what DSECT, COPY and INFO exactly change about output section?
from the official GNU ld documentation (which can be found easily with info ld):
DSECT
COPY
INFO
OVERLAY
These type names are supported for backward compatibility, and are
rarely used. They all have the same effect: the section should be
marked as not allocatable, so that no memory is allocated for the
section when the program is run
I just installed Perl 5.18, and I get a lot of warnings like this,
given is experimental at .\[...].pl line [...].
when is experimental at .\[...].pl line [...].
Smartmatch is experimental at C:/strawberry/perl/site/lib/[...] line [...].
Looking into these warnings -- which I've never heard mentioned anywhere -- I was only able to find this in two places,
perldelta for 5.18, which only really mentions insofar as to say that the feature has been downgraded to experimental?
this nntp.perl.org post
The Perl Delta still does the most to give mention as to what's happening with those features. It's halfway down buried in the pod,
Smart match, added in v5.10.0 and significantly revised in v5.10.1, has been a regular point of complaint. Although there are a number of ways in which it is useful, it has also proven problematic and confusing for both users and implementors of Perl. There have been a number of proposals on how to best address the problem. It is clear that smartmatch is almost certainly either going to change or go away in the future. Relying on its current behavior is not recommended. Warnings will now be issued when the parser sees ~~, given, or when.
I'm confused at how the most significant change in Perl in the past 10 years could be pulled. I've started using given, when, and smartmatch all over the place. Is there any more information about these futures? How is anyone finding them "confusing?" How are these features likely to change? Is there a plan to implement these features with a module?
There are problems with the design of smart-matching. The decision of what any given TYPE ~~ TYPE should do is most often unobvious, inconsistent and/or disputed. The idea isn't to remove smart matching; it's to fix it.
Specifically, ~~ will be greatly simplified, as you can see in a proposal by the 5.18 pumpking. Decisions as to how two things should match will be done with helpers such as those that already exist in Smart::Match.
... ~~ any(...)
It is much more readable, much more flexible (fully extensible), and solves a number of problems (such as "When should X be considered a number, and when should it be considered a string?").
Some insights might be gained by reading rjbs's proposed changes to smartmatch. He is the pumpking (Perl release manager) after all, so his comments and his view of the future is more relevant than most. There is also plenty of community comment on the matter; see here for instance. The 'experimental' status is in effect because, since things are likely to change in the future, it is responsible to inform users of that fact, even if we don't know what those changes will be.
Well, that's what's said in the description of the patch that downgraded this set of features to experimental:
The behavior of given/when/~~ are likely to change in perl 5.20.0:
either smart match will be removed or stripped down. In light of this,
users of these features should be warned. A category
"experimental::smartmatch" warning should be issued for these features
when they are used.
So while you can indeed turn these warnings off, with something like this (source):
no if $] >= 5.018, warnings => "experimental::smartmatch";
... it's just turning your eyes off the problem.
Christian Queinnec has written a masterpiece called LISP In Small Pieces, which features eleven Lisp Interpreters and two Lisp compilers.
When you go to download the code from the website here - it has the comment:
The programs of this book are available on the net.
These programs used to run with some Scheme systems around 1994.
Any idea:
(a) What Scheme systems these ran on at the time, and more importantly;
(b) What Scheme systems these would run on today?
There's a lot of programs in there. I did a few tests to see how well I could answer this without having to try them individually. There are 131 files in the tarball with extension ".scm". However there appear to be Scheme programs with other extensions such as .bgl. So I did a search for files containing 'L i S P' in the first five lines. That yields 173 files. I tried running all of these on my preferred Scheme implementation. 31 of these run without error. Almost all of these are in the "src" directory. So the language-specific programs really do seem language-specific. Let's look at one of the src/ files that failed, "chap9z.scm". It's choking on define-abbreviation. I don't know the origin of this symbol, but it's not defined anywhere in guile. But all of its uses could be performed by guile's syntax-rules.
Some Scheme implementations that existed in 1994 still are still around and maintained: Scheme 48, Chez Scheme, Gambit, Bigloo, MIT Scheme and SCM.
Probably the code from LiSP will run in other modern Scheme systems such as Guile or Larceny.
Personally, I would recommend using Racket. Most likely, much of the code will run in #lang racket with no changes, and there's no requirement to use [] (but your code may be easier to read :). Things that don't work are probably easy to fix, and you can also use the R5RS language implementation provided by Racket which will likely work for all of the code.
(a) What Scheme systems these ran on at the time
The Makefile in the source tarball from the author's website has targets for running the code under bigloo, elk, gambit, mit-scheme, scheme2c, and scm.
The Makefile mentions SCM 4e1 and Bigloo 1.9d as known working versions, though I haven't tested them myself. I didn't find any mention of specific versions for the other schemes.
(b) What Scheme systems these would run on today?
The code in this github repo has been updated so that almost all of the tests in the included test suite pass with current (as of 06/2014) versions of bigloo, gambit, and mit-scheme.
If you just want to be able to run the code and follow along with the book, one of those schemes should work for you.
[full disclosure: I'm the owner of the repo and I'm a Scheme noob. The code in the repo is WOMM certified, but your mileage may vary.]
If, on the other hand, you're not content to use bigloo / gambit / mit-scheme, it shouldn't be too hard to add support for guile / racket / insert-favorite-scheme-here. Use one of the book.* files as a starting point, e.g. gambit/book.scm or mitscheme/book.mit. If you can get a version of book.scm to load in your favorite scheme, then have a look at the test.interpreters make target, and finally the grand.test target to verify things are working as expected.
The included README file states:
These files were tested with a Scheme interpreter augmented with
a test-suite driver (tester.scm),
the define-syntax and define-abbreviation macros (using
Dybvig's syntax-case package),
and an object system: Meroonet (meroonet.scm).
Bigloo, Scheme->C, Gambit, Elk or SCM can be used. The first three are
better since a specialized interpreter may be built that contains a
compiled Meroonet and compiled hygienic macros.
Apparently Appleby has posted an updated version of the source code. Racket is missing though )=
See https://github.com/appleby/Lisp-In-Small-Pieces
I usually have an environment setting for MAKE_MODE (Windows XP, using GNU make, both under Cygwin and native)
set MAKE_MODE=UNIX
I now found differences between my build server (which has no MAKE_MODE defined) and a local build. This may be something completely different, but it got me wondering what other values I could specify for MAKE_MODE.
I think I know that MAKE_MODE=UNIX is suppose to tell GNU make to use /bin/sh - if it finds it - , but I quickly checked the GNU make manual and couldn't find a description. A google search only told me what I already know, but doesn't give a valid alternative.
Is the only alternative to not define the variable? Does it have influence at all when using CMD.exe and a native version of GNU make?
EDIT: So far I have found references for the values 'unix', 'win32', 'null' and undefined, but no explanations, and no specifications. But a look at the source code for GNU make 3.82 shows not a single occurrence of the string "MAKE_MODE", so GNUmake itself apparently doesn't change its behavior when this environment variable is set or not.
EDIT2: I checked the source code for GNU make for MinGW, and again found nothing. Maybe it's CygWin specific?
EDIT3: I found a reference that it might be property of an old version of GNU make, so I checked version 3.75. No luck, the string MAKE_MODE does not appear in the source code at all. The next step really must be the Cygwin version of GNU make. I know from 10 years ago that the Cygwin port in those days was not integrated in the regular source tree.
I found an ancient mailing list entry on the Cygwin site, explaining the basic operational effect of MAKE_MODE. This definitely indicates that the variable has to do with the Cygwin implementation of GNU make.
I'll dig around in the source code, and add to this answer when I find more details.
UPDATE: In a more recent post by maintainer Christopher Faylor I found the following update for GNU make version 3.81:
Note that the --win32 command line option and "MAKE_MODE" environment
variable are no longer supported in Cygwin's make. If you need to use a
Makefile which contains MS-DOS path names, then please use a MinGW
version of make.
I've not really found the values allowed for MAKE_MODE, but it's not any more necessary or supported in most recent versions of GNU make for Cygwin, and it was used for supporting DOS filenames in Cygwin's make.
And if you really want to know the set of allowed values, look in the source for Cygwin's make version before 3.81-1. I guess the only useful value was unix, all others will have meant the same.
Case closed? There's still not many views here...