I'm a beginning user of both Emacs and Clojure, testing my working environment with some simple text processing. I'm having problems getting the Slime REPL to properly print UTF-8 text stored in a vector.
I start by reading the contents of a file (a dictionary of Tocharian B) into a vector:
user> (def toch
(with-open [rdr (java.io.BufferedReader.
(java.io.FileReader. "/directory/toch.txt"))]
(vec (line-seq rdr))))
=> #'user/toch
I then try to get a line from the vector, and I get garbage:
user> (toch 44)
=> " Examples : /// kektseñe akappi ste ‘the body is an impurity’ (121b5), akappī = BHS aśuciṃ (529a3). "
I can enter the string into the Slime REPL and get it back as it should be:
user> " Examples : /// kektseñe akappi ste ‘the body is an impurity’ (121b5), akappī = BHS aśuciṃ (529a3). "
=> " Examples : /// kektseñe akappi ste ‘the body is an impurity’ (121b5), akappī = BHS aśuciṃ (529a3). "
And I can print to disk without any problem:
user> (binding [*out* (java.io.FileWriter. "test.txt")]
(prn (toch 44)))
=> nil
[Contents of test.txt: " Examples : /// kektseñe akappi ste ‘the body is an impurity’ (121b5), akappī = BHS aśuciṃ (529a3). "]
And getting lines from the vector from other REPLs (e.g. clj, lein repl) also works fine. It's only when I try to look at the contents of the vector within the Slime REPL that there's any problem.
What's going on here? Is there some miscommunication between Emacs and Swank? How can I fix this?
Try putting
(setq slime-net-coding-system 'utf-8-unix)
into your .emacs file (or setting and saving the variable via M-x customize-variable).
In addition, make sure that you are running Clojure from within a UTF-8-enabled locale (if you're on Un*x and using Leiningen, try something like env LC_ALL=en_US.UTF-8 lein swank).
Related
When I start an SML REPL and put in
print("floor is : " ^ (Int.toString (floor 3.1823)) ^ "\n");
I get
floor is : 3
val it = () : unit
i.e., expected behavior. But when I do the same thing in an Emacs org-mode source block:
#+name: sml_test
#+begin_src sml :exports both
print("floor is : " ^ (Int.toString (floor 3.1823)) ^ "\n");
#+end_src
I get the cryptic (for me)
#+RESULTS: sml_test
: val it = "stdIn" : string
Does anyone from the ML world know what this could mean?
This is probably a bug in ob-sml. If you visit the *sml* buffer, and do C-c C-c on the source block, the sml REPL gets this input:
print("floor is : " ^ (Int.toString (floor 3.1823)) ^ "\n");
; "stdIn";
Note the extra "stdIn" there. Also if you set :results output on the block, you should get the standard output of the block, but I get the same thing as with the default :results value setting (and the same thing you get: the cryptic thing which I guess is the result of that spurious "stdIn" - I should say that I know nothing about ML, so take all this with the appropriately sized grain of salt). I would open an issue on the ob-sml github project.
Currently, I have my global TODO list shown as follows thanks to erikstokes:
(org-agenda-prefix-format " %i %?-12(concat \"[ \"(org-format-outline-path (list (nth 1 (org-get-outline-path)))) \" ]\") ")))
which outputs:
for org layout:
However, as you can see, for Task A, even though there is nothing in the project, it still shows up on the list.
describe-variable for org-agenda-prefix-format says :
If the first character after `%' is a question mark, the entire field
will only be included if the corresponding value applies to the current
entry. This is useful for fields which should have fixed width when
present, but zero width when absent.
So I feel like by using %?, [ ] shouldn't be there for Task A, yet it still shows up.
The problem is that the field is never empty: it will always contain at least the left and right square brackets plus the white space to bring it to a width of 12.
The solution is to write a function that returns either an empty string or the bracketed project and use that in the format:
(defun foo ()
(let ((x (nth 1 (org-get-outline-path))))
(if x
(concat "[ " (org-format-outline-path (list x)) " ]")
"")))
(setq org-agenda-prefix-format " %i %?-12(foo) "
I'm trying to write a skeleton-function to output expressions in a loop. Out of a loop I can do,
(define-skeleton test
""
> "a")
When I evaluate this function it outputs "a" into the working buffer as desired. However, I'm having issues when inserting this into a loop. I now have,
(define-skeleton test
"A test skeleton"
(let ((i 1))
(while (< i 5)
>"a"
(setq i (1+ i)))))
I would expect this to output "aaaaa". However, instead nothing is outputted into the working buffer in this case. What is happening when I insert the loop?
The > somestring skeleton dsl does not work inside lisp forms.
You can however concatenate the string inside a loop:
(define-skeleton barbaz
""
""
(let ((s ""))
(dotimes (i 5)
(setq s (concat s "a")))
s)
)
My understanding is that code such as
> "a"
only works at the first nesting level inside a skeleton.
[EDIT] Regarding your question
What is happening when I insert the loop?
The return value of the let form (that is, the return value of the while form)is inserted. I do not know why it does not raise an error when evaluating > "a", but the return value of a while form is nil, so nothing is inserted.
I do agree that there's not much point using define-skeleton if you're going to need an (insert function within the skeleton.
This is also a rather trivial example to be using define-skeleton.
That said, they are often easier to read than a defun and useful when you want to create a function that inserts text (and optionally, takes input).
For example you may wish to have a different character repeated a set no. of times... Below, str refers to the argument supplied with the function (usually a string) and v1, v2 are the default names for local variables in a skeleton. Thus:
(define-skeleton s2 ""
nil ; don't prompt for value of 'str'
'(set 'v1 (make-string 5 (string-to-char str)))
\n v1 \n \n)
Below, calling the function leads to a newline, the string, then leaves the cursor at the position indicated by the square brackets [].
(s2 "a")
aaaaa
[]
I have a very simple example to illustrate the problem. Consider the following code block in Perl, in an org-mode file:
#+begin_src perl :results table
return qw(1 2 3);
#+end_src
It produces the following result:
#+results:
| 1\n2\n3\n |
which is not totally satisfactory since I was expecting a full org-table.
For instance, in Python the following code:
#+begin_src python :results table
return (1, 2, 3)
#+end_src
produces this result:
#+results:
| 1 | 2 | 3 |
So that's apparently working in Python but not in Perl. Am I doing something wrong? Is this a known bug?
Since I felt a little masochistic this morning I decided to take a shot at hacking a little lisp again. I cooked up a small fix which works for your example but I can't promise it will work more complex ones. So here it comes:
org-babel defines a wrapper for each language. The perl one did not produce something babel detects as a list so I modified it. In order to not make everything formated as a table I had to check if the result was printable as a table:
(setq org-babel-perl-wrapper-method
"
sub main {
%s
}
#r = main;
open(o, \">%s\");
if ($#r > 0) {
print o \"(\",join(\", \",#r), \")\",\"\\n\"
} else {
print o join(\"\\n\", #r), \"\\n\"
}")
You can modify this further to fit your needs if you want to.
The next thing is that the perl-evaluate method in babel does not run the output through further formating so I modified the evaluate method taking the new parts from the python-evaluate code:
(defun org-babel-perl-table-or-string (results)
"Convert RESULTS into an appropriate elisp value.
If the results look like a list or tuple, then convert them into an
Emacs-lisp table, otherwise return the results as a string."
(org-babel-script-escape results))
(defun org-babel-perl-evaluate (session body &optional result-type)
"Pass BODY to the Perl process in SESSION.
If RESULT-TYPE equals 'output then return a list of the outputs
of the statements in BODY, if RESULT-TYPE equals 'value then
return the value of the last statement in BODY, as elisp."
(when session (error "Sessions are not supported for Perl."))
((lambda (raw)
(if (or (member "code" result-params)
(member "pp" result-params)
(and (member "output" result-params)
(not (member "table" result-params))))
raw
(org-babel-perl-table-or-string (org-babel-trim raw))))
(case result-type
(output (org-babel-eval org-babel-perl-command body))
(value (let ((tmp-file (org-babel-temp-file "perl-")))
(org-babel-eval
org-babel-perl-command
(format org-babel-perl-wrapper-method body
(org-babel-process-file-name tmp-file 'noquote)))
(org-babel-eval-read-file tmp-file))))))
The new parts are org-babel-perl-table-or-string and the part in org-babel-perl-evaluate between the empty lines (plus 1 closing parenthesis at the end).
So what this now does is let perl print lists similar to the way python prints them and put the printed results through org-babel's formating procedures.
Now to the result:
A List:
#+begin_src perl :results value
return qw(1 2 3);
#+end_src
#+results:
| 1 | 2 | 3 |
A scalar:
#+begin_src perl :results value
return "Hello test 123";
#+end_src
#+results:
: Hello test 123
Ways you can use this code:
Place it in scratch and M-x eval-buffer for testing
Place it in a elsip src block at the beginning of your org-document
Place it in your .emacs after babel is loaded
Modify ob-perl.el in your lisp/org folder (might need to recompile org-mode afertwards)
I didn't not tested this much further than the output examples I gave you so if it misbehaves for other examples feel free to complain.
I'm both new and old to programming -- mostly I just write a lot of small Perl scripts at work. Clojure came out just when I wanted to learn Lisp, so I'm trying to learn Clojure without knowing Java either. It's tough, but it's been fun so far.
I've seen several examples of similar problems to mine, but nothing that quite maps to my problem space. Is there a canonical way to extract lists of values for each line of a CSV file in Clojure?
Here's some actual working Perl code; comments included for non-Perlers:
# convert_survey_to_cartography.pl
open INFILE, "< coords.csv"; # Input format "Northing,Easting,Elevation,PointID"
open OUTFILE, "> coords.txt"; # Output format "PointID X Y Z".
while (<INFILE>) { # Read line by line; line bound to $_ as a string.
chomp $_; # Strips out each line's <CR><LF> chars.
#fields = split /,/, $_; # Extract the line's field values into a list.
$y = $fields[0]; # y = Northing
$x = $fields[1]; # x = Easting
$z = $fields[2]; # z = Elevation
$p = $fields[3]; # p = PointID
print OUTFILE "$p $x $y $z\n" # New file, changed field order, different delimiter.
}
I've puzzled out a little bit in Clojure and tried to cobble it together in an imperative style:
; convert-survey-to-cartography.clj
(use 'clojure.contrib.duck-streams)
(let
[infile "coords.csv" outfile "coords.txt"]
(with-open [rdr (reader infile)]
(def coord (line-seq rdr))
( ...then a miracle occurs... )
(write-lines outfile ":x :y :z :p")))
I don't expect the last line to actually work, but it gets the point across. I'm looking for something along the lines of:
(def values (interleave (:p :y :x :z) (re-split #"," coord)))
Thanks, Bill
Please don't use nested def's. It doesn't do, what you think it does. def is always global! For locals use let instead. While the library functions are nice to know, here a version orchestrating some features of functional programming in general and clojure in particular.
(import 'java.io.FileWriter 'java.io.FileReader 'java.io.BufferedReader)
(defn translate-coords
Docstrings can be queried in the REPL via (doc translate-coords). Works eg. for all core functions. So supplying one is a good idea.
"Reads coordinates from infile, translates them with the given
translator and writes the result to outfile."
translator is a (maybe anonymous) function which extracts the translation from the surrounding boilerplate. So we can reuse this functions with different transformation rules. The type hints here avoid reflection for the constructors.
[translator #^String infile #^String outfile]
Open the files. with-open will take care, that the files are closed when its body is left. Be it via normal "drop off the bottom" or be it via a thrown Exception.
(with-open [in (BufferedReader. (FileReader. infile))
out (FileWriter. outfile)]
We bind the *out* stream temporarily to the output file. So any print inside the binding will print to the file.
(binding [*out* out]
The map means: take the seq and apply the given function to every element and return the seq of the results. The #() is a short-hand notation for an anonymous function. It takes one argument, which is filled in at the %. The doseq is basically a loop over the input. Since we do that for the side effects (namely printing to a file), doseq is the right construct. Rule of thumb: map: lazy => for result, doseq: eager => for side effects.
(doseq [coords (map #(.split % ",") (line-seq in))]
println takes care for the \n at the end of the line. interpose takes the seq and adds the first argument (in our case " ") between its elements. (apply str [1 2 3]) is equivalent to (str 1 2 3) and is useful to construct function calls dynamically. The ->> is a relatively new macro in clojure, which helps a bit with readability. It means "take the first argument and add it as last item to the function call". The given ->> is equivalent to: (println (apply str (interpose " " (translator coords)))). (Edit: Another note: since the separator is \space, we could here write just as well (apply println (translator coords)), but the interpose version allows to also parametrize the separator as we did with the translator function, while the short version would hardwire \space.)
(->> (translator coords)
(interpose " ")
(apply str)
println)))))
(defn survey->cartography-format
"Translate coords in survey format to cartography format."
Here we use destructuring (note the double [[]]). It means the argument to the function is something which can be turned into a seq, eg. a vector or a list. Bind the first element to y, the second to x and so on.
[[y x z p]]
[p x y z])
(translate-coords survey->cartography-format "survey_coords.txt" "cartography_coords.txt")
Here again less choppy:
(import 'java.io.FileWriter 'java.io.FileReader 'java.io.BufferedReader)
(defn translate-coords
"Reads coordinates from infile, translates them with the given
translator and writes the result to outfile."
[translator #^String infile #^String outfile]
(with-open [in (BufferedReader. (FileReader. infile))
out (FileWriter. outfile)]
(binding [*out* out]
(doseq [coords (map #(.split % ",") (line-seq in))]
(->> (translator coords)
(interpose " ")
(apply str)
println)))))
(defn survey->cartography-format
"Translate coords in survey format to cartography format."
[[y x z p]]
[p x y z])
(translate-coords survey->cartography-format "survey_coords.txt" "cartography_coords.txt")
Hope this helps.
Edit: For CSV reading you probably want something like OpenCSV.
Here's one way:
(use '(clojure.contrib duck-streams str-utils)) ;;'
(with-out-writer "coords.txt"
(doseq [line (read-lines "coords.csv")]
(let [[x y z p] (re-split #"," line)]
(println (str-join \space [p x y z])))))
with-out-writer binds *out* such that everything you print will go to the filename or stream you specify, rather than standard-output.
Using def as you're using it isn't idiomatic. A better way is to use let. I'm using destructuring to assign the 4 fields of each line to 4 let-bound names; then you can do what you want with those.
If you're iterating over something for the purpose of side-effects (e.g. I/O) you should usually go for doseq. If you wanted to collect up each line into a hash-map and do something with them later, you could use for:
(with-out-writer "coords.txt"
(for [line (read-lines "coords.csv")]
(let [fields (re-split #"," line)]
(zipmap [:x :y :z :p] fields))))