在slime REPL中使用clojure.contrib函数 [英] Using clojure.contrib functions in slime REPL

问题描述

我想在REPL中使用slime中clojure.contrib.trace命名空间中的函数。如何让泥煤自动加载？一个相关的问题，我如何添加一个特定的命名空间到正在运行的repl？

在clojure.contrib API它描述的用法如下：

 （ns my-namespace 
（：require clojure.contrib.trace））
  

但是将此添加到我的代码会导致文件无法从跟踪命名空间加载任何函数的无法解析符号错误。

我使用leiningen'lein swank'启动ServerSocket，并且project.clj文件如下所示：

 （defproject test-project0.1.0
：descriptionConnect 4用Clojure编写的代理
：dependencies [[org.clojure / clojure1.2.0-master-SNAPSHOT ] 
 [org.clojure / clojure-contrib1.2.0-SNAPSHOT]] 
：dev-dependencies [[leiningen / lein-swank1.2.0-SNAPSHOT] 
 [swank-clojure1.2.0]]）
  

一切似乎都是最新的， deps'不产生任何变化。那么是什么？

解决方案

1. 因为：require 不会从给定的命名空间中提取任何Vars，它只会使命名空间本身可用。

   
   
   

   因此，如果你 ns 表单中的（：require foo.bar），你必须写 foo.bar/quux 可从命名空间 foo.bar中访问Var quux >。您还可以使用（：require [foo.bar：as fb]）以将其缩短为 fb / quux 。最终可能是写（：use foo.bar）;这使得所有来自 foo.bar 的变量在您的命名空间中可用。注意，它一般被认为是不好的风格，：use 外部库;




2. Re：自动在REPL上提供资料：

   
   
   

   ：require ，：use 和：refer ns 表单在 require ， use 和指向 clojure.core 中的函数。还有对应于：refer-clojure 和：import 的宏。
   
   

   这意味着为了使 clojure.contrib.trace 在REPL可用，你可以做类似（require'clojure。 contrib.trace）或（require'[clojure.contrib.trace：as trace]）。注意，因为 require 是一个函数，你需要引用库规范。 （使用和引用也可以引用lib规范; import 和 refer-clojure 不需要引用。）

   
   
   

   每次启动时都有某些命名空间可用的最简单方法Clojure REPL（包括当你使用SLIME时）在〜/ .clojure / user.clj require $ c>。有关详细信息，请参阅要求所有可能的命名空间博文Lawrence Aspden说明你可以在 user.clj 中输入全部的贡献（我不这样做，虽然我有一个（使用'clojure.contrib.repl-utils）在那里）。




I want to use the functions in the clojure.contrib.trace namespace in slime at the REPL. How can I get slime to load them automatically? A related question, how can I add a specific namespace into a running repl?

On the clojure.contrib API it describes usage like this:

(ns my-namespace
  (:require clojure.contrib.trace))

But adding this to my code results in the file being unable to load with an "Unable to resolve symbol" error for any function from the trace namespace.

I use leiningen 'lein swank' to start the ServerSocket and the project.clj file looks like this

 (defproject test-project "0.1.0"
   :description "Connect 4 Agent written in Clojure"
   :dependencies [[org.clojure/clojure "1.2.0-master-SNAPSHOT"]
                  [org.clojure/clojure-contrib "1.2.0-SNAPSHOT"]]
   :dev-dependencies [[leiningen/lein-swank "1.2.0-SNAPSHOT"]
                      [swank-clojure "1.2.0"]])

Everything seems up to date, i.e. 'lein deps' doesn't produce any changes. So what's up?

解决方案

1. You're getting "Unable to resolve symbol" exceptions because :require doesn't pull in any Vars from the given namespace, it only makes the namespace itself available.

   Thus if you (:require foo.bar) in your ns form, you have to write foo.bar/quux to access the Var quux from the namespace foo.bar. You can also use (:require [foo.bar :as fb]) to be able to shorten that to fb/quux. A final possiblity is to write (:use foo.bar) instead; that makes all the Vars from foo.bar available in your namespace. Note that it is generally considered bad style to :use external libraries; it's probably ok within a single project, though.

2. Re: automatically making stuff available at the REPL:

   The :require, :use and :refer clauses of ns forms have counterparts in the require, use and refer functions in clojure.core. There are also macros corresponding to :refer-clojure and :import.

   That means that in order to make clojure.contrib.trace available at the REPL you can do something like (require 'clojure.contrib.trace) or (require '[clojure.contrib.trace :as trace]). Note that because require is a function, you need to quote the library spec. (use and refer also take quoted lib specs; import and refer-clojure require no quoting.)

   The simplest way to have certain namespaces available every time you launch a Clojure REPL (including when you do it with SLIME) is to put the appropriate require calls in ~/.clojure/user.clj. See the Requiring all possible namespaces blog post by John Lawrence Aspden for a description of what you might put in user.clj to pull in all of contrib (something I don't do, personally, though I do have a (use 'clojure.contrib.repl-utils) in there).

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