In typing statements of a proof into an Isabelle (2020) theory file, e.g.,
from ‹prime p › have p: "1 < p "
the jEdit interface application pops up a tooltip offering to insert an open cartouche command \<open> when I type a quotation mark. As you can see in the line above, I have been allowing this and it seems to be permitted. The Isabelle documentation seems to view inner syntax as category embedded, which seems to permit delineation with quotation marks or with the cartouche enclosure \<open ... \<close>.
Is there a down side to doing this? The imports statement requires quoting a reference to a theory file "HOL-Computational_Algebra.Primes" with module.theory format and will not accept cartouche there, but in theory statements it certainly appears to be equivalent.
Cartouches vs quotes is currently a matter of style, except for imports, syntax definitions, and for some command arguments (like nitpick[eval=".."]).
Remark that some keyboard layouts make it possible to type them directly (e.g., mac US international).
I believe that Makarius would like to deprecate the quotes eventually. This would allow users to write "a" instead of ''a'' for strings). But don't expect that to happen anytime soon.
So: Write what you like most!
Related
One of the useful features of ess-mode (Emacs speaks statistics) is to automatically replace the underscore _ with the assignment operator <-. Lately, I have been using a lot of pipes (written as %>%) and it would be great to not have to type three characters for each pipe.
Is it possible to define a custom key binding for the pipe, similar to the one converting _ into ->?
The simplest solution is to just bind a key to insert a string:
(define-key ess-mode-map (kbd "|") "%>%")
You can still insert | with C-q |. I'm not sure about the map's name; you'll almost certainly want to limit the key binding to ess-mode.
Check out yasnippet. You can use it to define something like "if this sequence of characters is followed by this key (which you can define to whatever you like), then replace them with this other sequence of characters and leave the cursor in this place". There's more to yasnippet than this, but there's plenty of documentation online and even already made recipes similar to the example I gave above that you can try, like yasnippet-ess-mode, for example.
Alternatively, you can also try abbrev-mode and see if that works for you.
I, for one, like yasnippet better, since you can also specify where to leave the cursor after the expansion, but abbrev-mode seems to be easier to set up. As always in Emacs world, try multiple solutions, don't settle for the first one you put your hands on. What works best for others might not work for you, and vice-versa.
I work with knitr() and I wish to transform inline Latex commands like "\label" and "\ref", depending on the output target (Latex or HTML).
In order to do that, I need to (programmatically) generate valid R strings that correctly represent the backslash: for example "\label" should become "\\label". The goal would be to replace all backslashes in a text fragment with double-backslashes.
but it seems that I cannot even read these strings, let alone process them: if I define:
okstr <- function(str) "do something"
then when I call
okstr("\label")
I directly get an error "unrecognized escape sequence"
(of course, as \l is faultly)
So my question is : does anybody know a way to read strings (in R), without using the escaping mechanism ?
Yes, I know I could do it manually, but that's the point: I need to do it programmatically.
There are many questions that are close to this one, and I have spent some time browsing, but I have found none that yields a workable solution for this.
Best regards.
Inside R code, you need to adhere to R’s syntactic conventions. And since \ in strings is used as an escape character, it needs to form a valid escape sequence (and \l isn’t a valid escape sequence in R).
There is simply no way around this.
But if you are reading the string from elsewhere, e.g. using readLines, scan or any of the other file reading functions, you are already getting the correct string, and no handling is necessary.
Alternatively, if you absolutely want to write LaTeX-like commands in literal strings inside R, just use a different character for \; for instance, +. Just make sure that your function correctly handles it everywhere, and that you keep a way of getting a literal + back. Here’s a suggestion:
okstr("+label{1 ++ 2}")
The implementation of okstr then needs to replace single + by \, and double ++ by + (making the above result in \label{1 + 2}). But consider in which order this needs to happen, and how you’d like to treat more complex cases; for instance, what should the following yield: okstr("1 +++label")?
Julia has docstrings capabilities, which are documented here https://docs.julialang.org/en/stable/manual/documentation/. I'm under the impression that it has support for LaTeX code, but I'm not sure if the intention is that the LaTeX code should look like code or like an interpretation. In the following, the LaTeX code is garbled somewhat (see rho, for instance) and not interpreted (rho does not look like ρ). Am I doing something wrong?
Is there a way to get LaTeX code look interpreted?
What I mean by interpreted is something like what they do at https://math.stackexchange.com/.
The documentation says that LaTeX code should be wrapped around double back-quotes and that Greek letters should be typed as ρ rather than \rho. But that rather defeats the point of being able to include LaTeX code, doesn't it?
Note: Version 0.5.2 run in Juno/Atom console.
"""
Module blabla
The objective function is:
``\max \mathbb{E}_0 \int_0^{\infty} e^{-\rho t} F(x_t) dt``
"""
module blabla
end
If I then execute the module and query I get this:
With triple quotes, the dollar signs disappear, but the formula is printed on a dark background:
EDIT Follow-up to David P. Sanders' suggestion to use the Documenter.jl package.
using Documenter
doc"""
Module blabla
The objective function is:
$\max \mathbb{E}_0 \int_0^{\infty} e^{-\rho t} F(x_t) dt$
"""
module blabla
end
Gives the following: the LaTeX code appears to print correctly, but it's not interpreted (ρ is displayed as \rho. I followed suggestions in: https://juliadocs.github.io/Documenter.jl/stable/man/latex.html to
Rendering LaTeX code as actual equations has to be supported by whichever software renders your docstrings. So, the short answer to why you're not seeing any rendered equations in Juno is that LaTeX rendering is currently not supported in Juno (as Matt B. pointed out, there's an open issue for that).
The doc"" string literal / string macro is there to get around another issue. Backslashes and dollar signs normally have a special meaning in string literals -- escape sequences and variable interpolation, respectively (e.g. \n gets replaced by a newline character, $(variable) inserts the value of variable into the string). This, of course, clashes with the ordinary LaTeX commands and delimiters (e.g. \frac, $...$). So, to actually have backslashes and dollar signs in a string you need to escape them all with backslashes, e.g.:
julia> "\$\\frac{x}{y}\$" |> print
$\frac{x}{y}$
Not doing that will either give an error:
julia> "$\frac{x}{y}$" |> print
ERROR: syntax: invalid interpolation syntax: "$\"
or invalid characters in the resulting strings:
julia> "``\e^x``" |> print
``^x``
Having to escape everything all the time would, of course, be annoying when writing docstrings. So, to get around this, as David pointed out out, you can use the doc string macro / non-standard string literal. In a doc literal all standard escape sequences are ignored, so an unescaped LaTeX string doesn't cause any issues:
julia> doc"$\frac{x}{y}$" |> print
$$
\frac{x}{y}
$$
Note: doc also parses the Markdown in the string and actually returns a Base.Markdown.MD object, not a string, which is why the printed string is a bit different from the input.
Finally, you can then use these doc-literals as normal docstrings, but you can then freely use LaTeX syntax without having to worry about escaping everything:
doc"""
$\frac{x}{y}$
"""
function foo end
This is also documented in Documenter's manual, although it is not actually specific to Documenter.
Double backticks vs dollar signs. The preferred way to mark LaTeX in Julia docstrings or documentation is by using double backticks or ```math blocks, as documented in the manual. Dollar signs are supported for backwards compatibility.
Note: Documenter's manual and the show methods for Markdown objects in Julia should be updated to reflect this.
You can use
doc"""
...
"""
This is a "non-standard string literal" used by the Documenter.jl package; see https://docs.julialang.org/en/stable/manual/strings/#non-standard-string-literals.
currently I am working on comparison between SICStus3 and SICStus4 but I got one issue that is SICStus4 will not consult any cases where the comment string has carriage controls or tab characters etc as given below.
Example case as given below.It has 3 arguments with comma delimiter.
case('pr_ua_sfochi',"
Response:
answer(amount(2370.09,usd),[[01AUG06SFO UA CHI Q9.30 1085.58FUA2SFS UA SFO Q9.30 1085.58FUA2SFS NUC2189.76END ROE1.0 XT USD 180.33 ZPSFOCHI 164.23US6.60ZP5.00AY XF4.50SFO4.5]],amount(2189.76,usd),amount(2189.76,usd),amount(180.33,usd),[[fua2sfs,fua2sfs]],amount(6.6,usd),amount(4.5,usd),amount(0.0,usd),amount(18.6,usd),lasttktdate([20061002]),lastdateafterres(200712282]),[[fic_ticketinfo(fare(fua2sfs),fic([]),nvb([]),nva([]),tktiss([]),penalty([]),tktendorsement([]),tourinfo([]),infomsgs([])),fic_ticketinfo(fare(fua2sfs),fic([]),nvb([]),nva([]),tktiss([]),penalty([]),tktendorsement([]),tourinfo([]),infomsgs([]))]],<>,<>,cat35(cat35info([])))
.
02/20/2006 17:05:10 Transaction 35 served by static.static.server1 (usclsefat002:7551) running E*Fare version $Name: build-2006-02-19-1900 $
",price(pnr(
user('atl','1y',<>,<>,dept(<>,'0005300'),<>,<>,<>),
[
passenger(adt,1,[ptconly(n)])
],
[
segment(1,sfo,chi,'ua','<>','100',20140901,0800,f,20140901,2100,'737',res(20140628,1316),hk,pf2(n,[],[],n),<>,flags(no,no,no,no,no,no,no,no,no)),
segment(2,chi,sfo,'ua','<>','101',20140906,1000,f,20140906,1400,'737',res(20140628,1316),hk,pf2(n,[],[],n),<>,flags(no,no,no,no,no,no,no,no,no))
]),[
rebook(n),
ticket(20140301,131659),
dbaccess(20140301,131659),
platingcarrier('ua'),
tax_exempt([]),
trapparm("trap:ffil"),
city(y)
])).
The below predicate will remove comment section in above case.
flatten-cases :-
getmessage(M1),
write_flattened_case(M1),
flatten-cases.
flatten-cases.
write_flattened_case(M1):-
M1 = case(Case,_Comment,Entry),!,
M2 = case(Case,Entry),
writeq(M2),write('.'),nl.
getmessage(M) :-
read(M),
!,
M \== end_of_file.
:- flatten-cases.
Now my requirement is to convert the comment string to an ASCII character list.
Layout characters other than a regular space cannot occur literally in a quoted atom or a double quoted list. This is a requirement of the ISO standard and is fully implemented in SICStus since 3.9.0 invoking SICStus 3 with the option --iso. Since SICStus 4 only ISO syntax is supported.
You need to insert \n and \t accordingly. So instead of
log('Response:
yes'). % BAD!
Now write
log('Response:\n\tyes').
Or, to make it better readable use a continuation escape sequence:
log('Response:\n\
\tyes').
Note that using literal tabs and literal newlines is highly problematic. On a printout you do not see them! Think of 'A \nB' which would not show the trailing spaces nor trailing tabs.
But there are also many other situations like: Making a screenshot of program text, making a photo of program text, using a 3270 terminal emulator and copying the output. In the past, punched cards. The text-mode when reading files (which was originally motivated by punched cards). Similar arguments hold for the tabulator which comes from typewriters with their manually settable tab stops.
And then on SO it is quite difficult to type in a TAB. The browser refuses to type it (very wisely), and if you copy it in, you get it rendered as spaces.
If I am at it, there is also another problem. The name flatten-case should rather be written flatten_case.
I've searched through several answers here and through Google, but I'm still not sure what's going wrong with my prompt.
According to the documentation I've read, this should work
setopt prompt_subst
autoload -U colors && colors
PROMPT="%{[00m[38;5;245m%}test %D%{[00m%}"
My prompt is the following, however:
[00m[38;5;245mtest 15-07-01[00m
Note that the date expansion actually worked, so prompt substitution is working. The ZSH man pages for prompt expansion states that %{...%} should be treated as a raw escape code, but that doesn't seem to be happening. Passing that string to print -P also results in the output above. I've found example prompts on the Internet for ZSH that also seem to indicate that the above syntax should work. See this for one example - the $FG and $FX arrays are populated with escape codes and are defined here. I've tried this example directly by merging both the files above, adding setopt prompt_subst to the beginning just to make sure it's set, then sourcing it and the prompt is a mess of escape codes.
The following works
setopt prompt_subst
autoload -U colors && colors
PROMPT=$'%{\e[00m\e[38;5;245m%}test %D%{\e[00m%}'
I get the expected result of test 15-07-01 in the proper color.
I've tested this on ZSH 5.0.5 in OSX Yosimite, 5.0.7 from MacPorts, and 4.3.17 on Debian, with the same results. I know I have provided a valid solution to my own problem here with the working example, but I'm wondering why the first syntax isn't working as it seems it should.
I think this all has to do with the timeless and perennial problem of escaping. It's worth reminding ourselves what escaping means, briefly: an escape character is an indicator to the computer that what follows should not be output literally.
So there are 2 escaping issues with:
PROMPT="%{[00m[38;5;245m%}test %D%{[00m%}"
Firstly, the colour escape sequences (eg; [00m) should all start with the control character like so \e[00m. You may have also seen it written as ^[00m and \003[00m. What I suspect has happened is one of the variations has suffered the common fate of being inadvertently escaped by either the copy/paste of the author or the website's framework stack, whether that be somewhere in a database, HTTP rendering or JS parsing. The control character (ie, ^, \e or \003), as you probably know, does not have a literal representation, say if you press it on the keyboard. That's why a web stack might decide to not display anything if it sees it in a string. So let's correct that now:
PROMPT="%{\e[00m\e[38;5;245m%}test %D%{\e[00m%}"
This actually nicely segues into the next escaping issue. Somewhat comically \e[ is actually a representation of ESC, it is therefore in itself an escape sequence marker that, yes, is in turn escaped by \. It's a riff on the old \\\\\\\\\\ sort of joke. Now, significantly, we must be clear on the difference between the escape expressions for the terminal and the string substitutions of the prompt, in pseudo code:
PROMPT="%{terminal colour stuff%}test %D%{terminal colour stuff%}"
Now what I suspect is happening, though I can't find any documentation to prove it, is that once ZSH has done its substitutions, or indeed during the substitution process, all literal characters, regardless of escape significations, are promoted to real characters¹. To yet further the farce, this promotion is likely done by escaping all the escape characters. For example if you actually want to print '\e' on the command line, you have to do echo "\\\e". So to overcome this issue, we just need to make sure the 'terminal colour stuff' escape sequences get evaluated before being assigned to PROMPT and that can be done simply with the $'' pattern, like so:
PROMPT=$'%{\e[00m\e[38;5;245m%}test %D%{\e[00m%}'
Note that $'' is of the same ilk as $() and ${}, except that its only function is to interpret escape sequences.
[1] My suspicion for this is based on the fact that you can actually do something like the following:
PROMPT='$(date)'
where $(date) serves the same purpose as %D, by printing a live version of the date for every new prompt output to the screen. What this specific examples serves to demonstrate is that the PROMPT variable should really be thought of as storage for a mini script, not a string (though admittedly there is overlap between the 2 concepts and thus stems confusion). Therefore, as a script, the string is first evaluated and then printed. I haven't looked at ZSH's prompt rendering code, but I assume such evaluation would benefit from native use of escape sequences. For example what if you wanted to pass an escape sequence as an argument to a command (a command that gets run for every prompt render) in the prompt? For example the following is functionally identical to the prompt discussed above:
PROMPT='%{$(print "\e[00m\e[38;5;245m")%}test $(date)%{$(print "\e[00m")%}'
The escape sequences are stored literally and only interpreted at the moment of each prompt rendering.