What's the preferred way to run a raco command from a script?
I've been doing things like:
#lang racket
(system "raco frog -b")
but there has got to be a better solution.
Yes indeed, there is a better way:
#lang racket
(require raco/all-tools)
(define v (all-tools))
(parameterize ([current-command-line-arguments (vector "-b")])
(dynamic-require (second (hash-ref v "frog")) #f))
Many thanks to Sam Tobin-Hochstadt.
https://github.com/racket/racket-lang-org/pull/26#issuecomment-267160884
Related
I'd like to take an existing language, say, htdp/isl, and add a few definitions that aren't included by default. I can (require blah) at the top of every file, but I want to just be able to write #lang my-modified-isl at the top, and get those definitions along with the rest of the language. It's okay if this only works for languages that are "close" to Racket (i.e., have a boring reader).
In Racket, a #lang is basically just any module that provides #%module-begin (and optionally a reader/parser). As an example, you can check out my SML package (no relation to Standard ML), which is almost vanilla Racket, but a few custom tweaks to make it really good for describing data (like YAML).
Let's say you want to make a version of vanilla Racket, but that includes the function standard-fish, and lacks a divide (/) function. You could make your file:
#lang racket ; custom-racket.rkt
(require pict)
(provide (except-out (all-from-out racket) /)
standard-fish)
And now you can use s-exp to put your new language in the #lang line:
#lang s-exp "custom-racket.rkt"
(standard-fish) ; A fish
(/ 10 2) ; Error, `/` undefined
(Note that if you want to get rid of S-Expressions entirely and replace the reader, you would use #lang reader instead.)
Finally, you can package your file into a custom Racket package to use directly. Rename custom-racket.rkt from above to custom-racket/main.rkt, add an info.rkt file, and install the package:
$ mkdir custom-racket
$ cd custom-racket
$ vim main.rkt
#lang racket ; custom-racket.rkt
(require pict)
(provide (except-out (all-from-out racket) /)
standard-fish)
(module reader syntax/module-reader
custom-lang)
$ vim info.rkt
#lang info
(define collection "custom-racket")
$ raco pkg install
And now you can use custom-racket directly in the #lang line:
#lang custom-racket
(standard-fish) ; A fish
(/ 10 2) ; Error, `/` undefined
I'm looking for some assistance, please, to programmatically distinguish between system-type Windows XP versus Windows 7 -- using the same Emacs version.
Emacs Version: GNU Emacs 24.3.94.1 (i686-pc-mingw32) of 2014-10-02 on LEG570
I would like to do something like:
(cond
((eq system-type 'darwin)
. . .)
((and
(eq system-type 'windows-nt)
(eq ... Windows XP)) ;; pseudocode
. . .)
((and
(eq system-type 'windows-nt)
(eq ... Windows 7)) ;; pseudocode
. . .) )
Try M-:x (w32-version) RET on those two systems. The result should be different.
Then use it in something like:
(cond ((equal (w32-version) '...) ...)
I think that the approach here would be the following:
Have sub-conditions when the system-type is 'windows-nt.
Parse the output of some foreign code to get the Windows variant.
Approach 1 : Dummy shell command(output specific to OS locale??)
Use ver to get the os version.
http://www.windows-commandline.com/find-windows-os-version-from-command/
The above approach might produce different string output based on the user locale settings.
Approach 2 : Use some external custom code
Alternatively you could compile some external C++ app and deal with OS semantic versions mappings (http://support2.microsoft.com/kb/307394)
Then things become simple
if system-type is windows-nt
variant = parse (shell-command-to-string "ver")
conditions to run code for interesting variant with a default :else case
There is a defun in .emacs to get erlang project path, how can I execute a shell-command to do the following:
cd *~/erlang-project-folder*
make
I'm using rebar to build my project, and there is a Makefile to do everything.
I can compile by overriding erlang-compile-function, but I'm not familiar with Emacs Lisp, please help.
Here is my .emacs:
(defun erlang-project-dir ()
(let* ((src-path (file-name-directory (buffer-file-name)))
(pos (string-match "/src/" src-path)))
(if pos (substring src-path 0 (+ 1 pos)) src-path)))
;; there is an error: wrong type argument: commandp
(defun my-inferior-erlang-compile ()
(shell-command.
(concat (concat (concat "cd" erlang-project-dir) "; make"))))
(defvar erlang-compile-function 'my-inferior-erlang-compile)
Instead of relying on directory structure, it's better to try to locate the rebar.config file that is in the root of your project. This could be achieved with following code:
(defun my-find-rebar-root ()
(let ((dir (locate-dominating-file default-directory "rebar.config")))
(or dir default-directory)))
and after that you can use this function for compilation:
(defun my-inferior-erlang-compile ()
(interactive)
(let ((default-directory (my-find-rebar-root)))
(compile "make")))
Although, I'm not sure that the make is right command here - maybe it's better to use rebar compile instead?
P.S. I hope, that I'll find some free time, and will finish rebar support in EDE - in this case, it will be the same unified interface for work with projects.
Sorry for my poor English.
I'm configuring my emacs with erlang flymake. Source files in src's nested folders report 'can't find include file', but files in src/folder can find the include file.
My emacs settings for erlang:
;; erlang-mode
(setq load-path (cons "/usr/local/Cellar/erlang/R15B02/lib/erlang/lib/tools-2.6.8/emacs" load-path))
(setq erlang-root-dir "/usr/local/Cellar/erlang/R15B02/lib/erlang")
(setq exec-path (cons "/usr/local/Cellar/erlang/R15B02/lib/erlang/bin" exec-path))
(require 'erlang-start)
;; distel
(add-to-list 'load-path "/usr/local/share/distel/elisp/")
(require 'distel)
(distel-setup)
;; erlang-flymake
(require 'erlang-flymake)
(erlang-flymake-only-on-save)
My erlang application folder is like following:
app/src/ (source code)
src/mod
src/lib
app/include/ (hrls)
app/ebin/ (compiled code)
...etc
In erlang-flymake there are 2 variables (erlang-flymake-get-include-dirs-function and erlang-flymake-get-code-path-dirs-function), that specify functions to search include & ebin directories. Right now, they're pointing to the functions erlang-flymake-get-include-dirs and erlang-flymake-get-code-path-dirs that simply return current dir + include and ebin correspondingly. For example, you can use following code to do this:
(defun get-erlang-app-dir ()
(let* ((src-path (file-name-directory (buffer-file-name)))
(pos (string-match "/src/" src-path)))
(if pos
(substring src-path 0 (+ 1 pos))
src-path)))
(setq erlang-flymake-get-code-path-dirs-function
(lambda ()
(concat (get-erlang-app-dir) "ebin")))
(setq erlang-flymake-get-code-include-dirs-function
(lambda ()
(concat (get-erlang-app-dir) "include")))
P.S. Are you using rebar to maintain your project?
If you use erlang-flymake you might want to look at https://github.com/ten0s/syntaxerl. It's a syntax checker for Erlang. It uses erlang-flymake under the hood, but instead of `erlc' it uses a custom syntax checker that can evaluate .erl, .hrl, .config, .rel, .app, .app.src, .escript files. The syntax checker is rebar aware, but also works with standard Erlang/OTP directory structure. Emacs's setup is also there.
It's a very easy scheme function
(define member?
(lambda (a lat)
(cond
((null? lat) #f)
(else (or (eq? (car lat) a)
(member? a (cdr lat))
))
)
)
)
However, when I pressed ,d or ,F in vim to run this function, there is an error
/home/oo/tmp/t.scm:64 read-error: no dispatch function defined for
#\F
Line: 4, Column: 21, File-Position: 64
Stream: #<SB-SYS:FD-STREAM for "file /home/oo/tmp/t.scm" {AC84DA9}>
Chris already pointed out that you tried to use Scheme code with a Common Lisp swank server.
You need to run a Scheme swank server (e.g. swank-mit-scheme.scm, also included in Slimv).
Normally Slimv should autodetect MIT scheme on Linux without any tweaking in the .vimrc. For the autodetection to work properly you need MIT Scheme installed and the scheme command be available.
I suggest that you remove any Slimv related settings from your .vimrc. Then load the .scm in Vim and type this command:
:echo SlimvSwankCommand()
If Scheme was autodetected then this should print the command that runs the Scheme swank server (search for swank-mit-scheme.scm in the output). If the autodetection was unsuccessful then either you don't have the scheme command or Slimv did not find swank-mit-scheme.scm. In this case you need to tell Slimv the command to run the Scheme swank server. You can do in by adding a similar command to your .vimrc:
let g:slimv_swank_cmd = '! xterm -e scheme --load /your-path-to/slime/contrib/swank-mit-scheme.scm &'
But do this only if autodetection fails. If you need some more assistance, please feel free to contact me, I'm the author of Slimv.