I'd like to be able to only import namespaced items from a module in Racket. The prefix-in function does allow me to access functions from the module using the prefix, but it doesn't hide the old name.
$ racket
Welcome to Racket v6.6.
> (require (prefix-in tcp: racket/tcp))
> tcp-accept
#<procedure:tcp-accept>
> tcp:tcp-accept
#<procedure:tcp-accept>
Is there a simple way to hide the unprefixed names?
The prefix-in form only imports the prefixed names, not the unprefixed ones. However, the racket language includes the racket/tcp module by default, so it is already imported when the REPL starts up. If you use #lang racket/base, instead, then tcp-accept won’t be imported, so the prefixed import will be the only imported identifier. You can simulate this using the -I racket/base option in the REPL:
$ racket -iI racket/base
Welcome to Racket v6.7.0.4.
> (require (prefix-in tcp: racket/tcp))
> tcp-accept
; tcp-accept: undefined;
; cannot reference undefined identifier
; [,bt for context]
> tcp:tcp-accept
#<procedure:tcp-accept>
Related
If I evaluate the following in Emacs Cider:
(use 'alembic.still)
(alembic.still/distill '[enlive "1.1.5"])
(require '[net.cgrand.enlive-html :as html])
(html)
... evaluation of the (html) to see if it's a recognized symbol produces an 'Unable to resolve symbol' error. I'm evaluating it via cider connected to a REPL.
How can I use Alembic provided dependencies as an alias?
Your code is not working because html is an alias for a namespace here, not a symbol. The functions from enlive should work, however:
(use 'alembic.still)
(alembic.still/distill '[enlive "1.1.5"])
(require '[net.cgrand.enlive-html :as html])
(html/html-snippet "<div>Hello world</div>")
I'm working through the newly released Vulkan Tutorial in Clojure with CIDER, and I've hit a bit of a snag. The example makefile project works perfectly, but I'm having trouble translating it into Clojure.
My build.boot file just specifies the :source-paths and adds LWJGL as a dependency:
(set-env!
:source-paths #{"src"}
:dependencies
(let [lwjgl-version "3.0.0"]
[['org.lwjgl/lwjgl lwjgl-version]
['org.lwjgl/lwjgl-platform lwjgl-version :classifier "natives-linux"]]))
Then, in src/example/core.clj, I have an extension-count function that uses vkEnumerateInstanceExtensionProperties as demonstrated in the original example:
(ns example.core
(:import (org.lwjgl.vulkan VK10)))
(defn extension-count []
(let [^String layer-name nil
property-count (int-array 1)]
(VK10/vkEnumerateInstanceExtensionProperties layer-name property-count nil)
(first property-count)))
Now, from Bash, I can set the relevant environment variables LD_LIBRARY_PATH and VK_LAYER_PATH as I start up a REPL:
$ VULKAN_SDK_PATH=~/VulkanSDK/1.0.21.1/x86_64 LD_LIBRARY_PATH=$VULKAN_SDK_PATH/lib VK_LAYER_PATH=$VULKAN_SDK_PATH/etc/explicit_layer.d boot repl
boot.user=> (require '[example.core :refer [extension-count]])
nil
boot.user=> (extension-count)
4
As you can see, everything works correctly. But of course, when I use cider-jack-in by C-c M-j instead, I get an UnsatisfiedLinkError because CIDER isn't setting those variables:
boot.user> (import (java.util.function Consumer)
(org.lwjgl.system Configuration))
org.lwjgl.system.Configuration
boot.user> (Configuration/setDebugStreamConsumer
(reify Consumer
(accept [_ message]
(println message))))
nil
boot.user> (require '[example.core :refer [extension-count]])
nil
boot.user> (extension-count)
[LWJGL] Failed to load a library. Possible solutions:
a) Set -Djava.library.path or -Dorg.lwjgl.librarypath to the directory that contains the shared libraries.
b) Add the JAR(s) containing the shared libraries to the classpath.
[LWJGL] Enable debug mode with -Dorg.lwjgl.util.Debug=true for better diagnostics.
java.lang.UnsatisfiedLinkError: Failed to locate library: libvulkan.so.1
Am I supposed to be setting java.library.path or org.lwjgl.librarypath, as suggested in the above error message, instead of LD_LIBRARY_PATH? I can set either of those variables from profile.boot:
(System/setProperty
"java.library.path"
(str (System/getProperty "user.home") "/VulkanSDK/1.0.21.1/x86_64/lib"))
Now when I try C-c M-j again, it works:
boot.user> (require '[example.core :refer [extension-count]])
nil
boot.user> (extension-count)
4
However, this still doesn't let me set VK_LAYER_PATH, which will be fairly important in the future:
We will start using validation layers in Vulkan and you need to tell the Vulkan library where to load these from using the VK_LAYER_PATH variable:
test: VulkanTest
LD_LIBRARY_PATH=$(VULKAN_SDK_PATH)/lib VK_LAYER_PATH=$(VULKAN_SDK_PATH)/etc/explicit_layer.d ./VulkanTest
How can I set these environment variables for cider-jack-in? I'd prefer not to have to manually configure CIDER's dependencies for a standalone repl in a separate terminal and then connect to it using cider-connect, but if there's no other option here, I guess that's what I'll have to do.
Given this code:
#lang racket/base
(module+ test
(require rackunit rackunit/text-ui)
(provide suite)
(define suite
(test-suite
"test tests"
(test-equal? "test string test"
"string"
"string")))
(run-tests suite))
;(require 'test)
;(suite)
If the last two lines are left commented and the file is run with raco test test.rkt, will output
raco test: (submod "test.rkt" test)
1 success(es) 0 failure(s) 0 error(s) 1 test(s) run
0
1 test passed
Which is expected.
How can I make the file run its tests when it's run just as a script, not by raco?
I thought the two commented lines at the end would do what I want: import the submodule and then call the function,
(require 'test)
(suite)
but instead I get:
$ racket test.rkt
require: unknown module
module name: #<resolved-module-path:'test>
context...:
standard-module-name-resolver
Learn Racket in Y Minutes seems to say that 'test as a 'symbol is for submodules, but perhaps not.
Submodules declared with module+ and module* aren't available for require in their containing module because they can depend on their containing module, and cycles in the module dependency graph aren't allowed. (In contrast, submodules declared with module can't depend on their containing module, but their containing module can require them.)
Try adding a main submodule; that should get run when the file is run as a script:
(module+ main
(require (submod ".." test))
(run-tests suite))
BTW, the Racket convention is for the test submodule to run the tests, not just to define them. Adding a main submodule might make raco test stop working for your script; the fix would be to move the (run-tests suite) call to the test submodule instead.
I'm a Lisp beginner trying to understand how to properly use Lisp package system while learning LTK for GUI programming, using SBCL 1.0.55.0.debian and Limp 0.3.4 (and Debian Wheezy if that matters). I have installed ASDF using aptitude package manager (packages cl-asdf & cl-common-lisp-controller), then I installed Quicklisp using the instructions on Quicklisp website (http://www.quicklisp.org/beta/index.html) (not from Debian repository) and then I have installed LTK with (ql:quickload 'ltk) in SBCL console.
hello-1.lisp (directly from LTK tutorial):
(defun hello-1()
(with-ltk ()
(let ((b (make-instance ’button
:master nil
:text "Press Me"
:command (lambda ()
(format t "Hello World!~&")))))
(pack b))))
If I compile this straight on in a new SBCL Lisp image, I get the message that WITH-LTK and PACK are undefined functions and 'BUTTON is undefined variable.
So, I found out that I need to load 'ltk first and then use in-package.I to be able to run it, I first have to use (ql:quickload 'ltk) and (in-package :ltk) in SBCL console. However, I still an error message that 'BUTTON is undefined variable.
* (ql:quickload 'ltk)
To load "ltk":
Load 1 ASDF system:
ltk
; Loading "ltk"
(LTK)
* (in-package :ltk)
#<PACKAGE "LTK">
* (compile-file "/home/user/code/lisp/hello-1.lisp")
; caught WARNING:
; undefined variable: ’BUTTON
;
; compilation unit finished
; Undefined variable:
; ’BUTTON
; caught 1 WARNING condition
; /home/user/code/lisp/hello-1.fasl written
; compilation finished in 0:00:00.009
#P"/home/user/code/lisp/hello-1.fasl"
T
T
*
Then, as this didn't work out as I wanted, I also attempted to define my own package definitions according to the answers of another question (Problems with ltk (common lisp)), Xach's blog entry "Making a small Lisp project with quickproject and Quicklisp" http://xach.livejournal.com/278047.html?thread=674335 and ASDF Manual (http://common-lisp.net/project/asdf/asdf/The-defsystem-form.html) using quickproject:make-project, but without success. Currently I have the following files:
package.lisp (compiles cleanly if I first (ql:quickload 'ltk) SBCL REPL):
(defpackage :hello-world-ltk-system
(:use :cl :asdf :ltk))
hello-world-ltk.asd (compiles cleanly after I have first compiled package.lisp):
(in-package :hello-world-ltk-system)
(asdf:defsystem :hello-world-ltk
:serial t
:description "Describe hello-world-ltk here"
:author "Your Name <your.name#example.com>"
:license "Specify license here"
:depends-on (:cl :asdf :ltk)
:components ((:file "package")
(:file "hello-world-ltk")))
hello-world-ltk.lisp (I get compile error The name "HELLO-WORLD-LTK" does not designate any package).
(require 'hello-world-ltk)
(in-package :hello-world-ltk)
(defun hello-world-1 ()
(with-ltk ()
(let ((b (make-instance 'button
:master nil
:text "Press me!"
:command (lambda ()
(format t "Hello world!~&")))))
(pack b))))
When I attempt to compile this hello-world-ltk.lisp after successfully compiling package.lisp and hello-world-ltk.asd (which all reside in the same directory) I get the following error:
; compiling (IN-PACKAGE :HELLO-WORLD-LTK)
debugger invoked on a SB-KERNEL:SIMPLE-PACKAGE-ERROR in thread
#<THREAD "initial thread" RUNNING {10029A0FA3}>:
The name "HELLO-WORLD-LTK" does not designate any package.
Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL.
restarts (invokable by number or by possibly-abbreviated name):
0: [ABORT] Exit debugger, returning to top level.
(SB-INT:%FIND-PACKAGE-OR-LOSE "HELLO-WORLD-LTK")
0]
(load "/home/user/code/lisp/hello-world-ltk/hello-world-ltk")
debugger invoked on a SIMPLE-ERROR in thread
#<THREAD "initial thread" RUNNING {10029A0FA3}>:
attempt to load an empty FASL file:
"/home/user/code/lisp/hello-world-ltk/hello-world-ltk.fasl"
Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL.
restarts (invokable by number or by possibly-abbreviated name):
0: [ABORT] Reduce debugger level (to debug level 1).
1: Exit debugger, returning to top level.
(SB-FASL::LOAD-AS-FASL
#<SB-SYS:FD-STREAM
for "file /home/user/code/lisp/hello-world-ltk/hello-world-ltk.fasl"
{1005291233}>
NIL
#<unavailable argument>)
0[2]
So, I'm quite lost here with all different ways to define packages, ASDF, Quicklisp, package.lisp, quickproject, asdf:defsystem, require and ql:quickload... quickproject:make-project looks promising, but I really don't know what's still wrong with my source files. I'm looking for a solution that should handle all the compilations and package loadings preferibly in one single command for the whole project and that should be extendable for bigger projects too.
Thank you for any help :)
The first problem in your code is that you use apostrophe (’) instead of tick ('). That's why you get undefined variable error, as ’button is read as variable name (it's not quoted).
Now regarding packages and systems. A package is defined with defpackage and it is a collection of symbols, which are used after the in-package form inside a file (or in interactive session). A package has internal and external (exported) symbols, that can be accessed as package::internal-symbol and package:external-symbol respectively. Packages can also import symbols from other packages. If you use-package, you import all its external symbols. While in-package switches the current package to the specified one and you start to define symbols in it (and it is not desirable to do such things in 3rd-party packages, like LTK). So if you want to use LTK symbols, like with-ltk or button, you just need to either use-package LTK or import these symbols from LTK in your defpackage form:
(defpackage :hello-world-ltk-system
(:use :cl)
(:import-from :ltk :with-ltk :button))
or simply import all LTK symbols (with use clause):
(defpackage :hello-world-ltk-system
(:use :cl :ltk))
Finally, systems and packages are totally unrelated things. A system is an instance of a class ASDF:SYSTEM, which holds information about physical files and their relations, so that they can be compiled and loaded appropriately. For your hello-world application I would suggest, that you don't bother about systems for now, and write all your code in one file. This file should start with a defpackage form, followed by in-package, and then the rest of your code.
When this file will grow large enough, that you'll see clear parts in it, you can factor out those parts into separate files. Then you'll have to create a system definition file, that will look like this:
(asdf:defsystem :hello-world
:depends-on (:ltk)
:serial t
:components ((:file "package")
(:file "first")
(:file "second")
...))
The "package.lisp" file will now hold your package definition.
I have been reading a lot about Reinforcement Learning lately, and I have found "Reinforcement Learning: An Introduction" to be an excellent guide. The author's helpfully provice source code for a lot of their worked examples.
Before I begin the question I should point out that my practical knowledge of lisp is minimal. I know the basic concepts and how it works, but I have never really used lisp in a meaningful way, so it is likely I am just doing something incredibly n00b-ish. :)
Also, the author states on his page that he will not answer questions about his code, so I did not contact him, and figured Stack Overflow would be a much better choice.
I have been trying to run the code on a linux machine, using both GNU's CLISP and SBCL but have not been able to run it. I keep getting a whole list of errors using either interpreter. In particular, most of the code appears to use a lot of utilities contained in a file 'utilities.lisp' which contains the lines
(defpackage :rss-utilities
(:use :common-lisp :ccl)
(:nicknames :ut))
(in-package :ut)
The :ccl seems to refer to some kind of Mac-based version of lisp, but I could not confirm this, it could just be some other package of code.
> * (load "utilities.lisp")
>
> debugger invoked on a
> SB-KERNEL:SIMPLE-PACKAGE-ERROR in
> thread #<THREAD "initial thread"
> RUNNING {100266AC51}>: The name
> "CCL" does not designate any package.
>
> Type HELP for debugger help, or
> (SB-EXT:QUIT) to exit from SBCL.
>
> restarts (invokable by number or by
> possibly-abbreviated name): 0:
> [ABORT] Exit debugger, returning to
> top level.
>
> (SB-INT:%FIND-PACKAGE-OR-LOSE "CCL")
I tried removing this particular piece (changing the line to
(:use :common-lisp)
but that just created more errors.
> ; in: LAMBDA NIL ; (+
> RSS-UTILITIES::*MENUBAR-BOTTOM* ;
> (/ (- RSS-UTILITIES::MAX-V
> RSS-UTILITIES::V-SIZE) 2)) ; ; caught
> WARNING: ; undefined variable:
> *MENUBAR-BOTTOM*
>
> ; (-
> RSS-UTILITIES::*SCREEN-HEIGHT*
> RSS-UTILITIES::*MENUBAR-BOTTOM*) ; ;
> caught WARNING: ; undefined
> variable: *SCREEN-HEIGHT*
>
> ; (IF RSS-UTILITIES::CONTAINER ;
> (RSS-UTILITIES::POINT-H ;
> (RSS-UTILITIES::VIEW-SIZE
> RSS-UTILITIES::CONTAINER)) ;
> RSS-UTILITIES::*SCREEN-WIDTH*) ; ;
> caught WARNING: ; undefined
> variable: *SCREEN-WIDTH*
>
> ; (RSS-UTILITIES::POINT-H
> (RSS-UTILITIES::VIEW-SIZE
> RSS-UTILITIES::VIEW)) ; ; caught
> STYLE-WARNING: ; undefined function:
> POINT-H
>
> ; (RSS-UTILITIES::POINT-V
> (RSS-UTILITIES::VIEW-SIZE
> RSS-UTILITIES::VIEW)) ; ; caught
> STYLE-WARNING: ; undefined function:
> POINT-V
Anybody got any idea how I can run this code? Am I just totally ignorant of all things lisp?
UPDATE [March 2009]: I installed Clozure, but was still not able to get the code to run.
At the CCL command prompt, the command
(load "utilities.lisp")
results in the following error output:
;Compiler warnings :
; In CENTER-VIEW: Undeclared free variable *SCREEN-HEIGHT*
; In CENTER-VIEW: Undeclared free variable *SCREEN-WIDTH*
; In CENTER-VIEW: Undeclared free variable *MENUBAR-BOTTOM* (2 references)
> Error: Undefined function RANDOM-STATE called with arguments (64497 9) .
> While executing: CCL::READ-DISPATCH, in process listener(1).
> Type :GO to continue, :POP to abort, :R for a list of available restarts.
> If continued: Retry applying RANDOM-STATE to (64497 9).
> Type :? for other options.
1 >
Unfortuately, I'm still learning about lisp, so while I have a sense that something is not fully defined, I do not really understand how to read these error messages.
My guess is that the code is CCL-dependent, so use CCL instead of CLISP or SBCL. You can download it from here: http://trac.clozure.com/openmcl
That code is for Macintosh Common Lisp (MCL). It will only run there. Using Clozure CL (CCL) will not help. You would have to comment the graphics code. The random state stuff also is slightly special for MCL. You have to port it to portable Common Lisp (make-random-state, etc.). Also the file names are special for the Mac.
Clozure CL is a fork from Macintosh Common Lisp, but has be changed to Unix conventions (pathnames, ...) and does not include the special graphics code of MCL.
Using the latest version of CCL on linux x86, with this file saved as foo.lisp:
#+ccl (defun random-state (x y)
(ccl::initialize-random-state x y))
(load "utilities.lisp")
(use-package 'rss-utilities)
(load "testbed.lisp")
(setup)
(init)
(print (runs 10 10 .1))
Running
~/svn/ccl/lx86cl -l foo.lisp
prints a bunch of warning messages and the desired answer of:
(-0.77201915 0.59691894 0.78171235 0.41514033 0.6744591 0.26383805 0.8981678 1.1274683 0.50265205 0.4081622)
To figure out the required #'random-state defun, I guessed that the “#.(RANDOM-STATE 64497 9)” was a serialized random-state object from MCL. To see how CCL handles that, I checked what MAKE-RANDOM-STATE outputs in CCL:
$ ~/svn/ccl/lx86cl
Welcome to Clozure Common Lisp Version 1.3-r11936 (LinuxX8632)!
? (make-random-state)
#.(CCL::INITIALIZE-RANDOM-STATE 64497 9)
If you have never used lisp in a meaningful way, there is a Matlab code for "Reinforcement Learning: An Introduction".
In addition to Rainer Joswig's answer: Once you install Clozure you'll have to update references to the function RANDOM-STATE in utilities.lisp to random-mrg31k3p-state.
More specifically replace: #.(RANDOM-STATE 64497 9) with #.(ccl::random-mrg31k3p-state)
random-mrg31k3p-state seems to have replaced random-state sometime after the code was written see l1-numbers.lisp?rev=13327