read-eval-print-loop

How can I start an interactive console for Perl, similar to the irb command for Ruby or python for Python? You can use the perl debugger on a trivial program, like so: perl -de1 Alternatively there's Alexis Sukrieh 's Perl Console application, but I haven't used it. Not only did Matt Trout write an article about a REPL, he actually wrote one - Devel::REPL I've used it a bit and it works fairly well, and it's under active development. BTW, I have no idea why someone modded down the person who mentioned using "perl -e" from the console. This isn't really a REPL, true, but it's fantastically

I've noticed that Playgrounds in Xcode 10 no longer allow for the use of declared, but uninitialized variables. For example: while this code would work in an Xcode 9 playground, in an Xcode 10 playground (at least in Beta 1), it crashes: var myValue: Int //... myValue = 100 print (myValue) // Xcode 9 prints 100 // Xcode 10 reports an error: variables currently must have an initial value when entered at the top level of the REPL Is this the new behavior, or just a bug in the current Xcode 10 beta? I had been referring to earlier Xcode Playgrounds as an interpreter, but would one still consider

Writing (in-ns 'dbx) to a file and loading it isn't changing the default namespace of the repl (using cygwin/console). The namespace is still user=> , not dbx=> . vikrant[28] clj Clojure 1.3.0 user=> (load-file "try1.clj") #(Namespace dbx) user=> How can we start the REPL in a namespace defined in a script file? BLUEPIXY java -cp .;clojure-1.3.0.jar; clojure.main -e \ "(ns dbx) (clojure.main/repl) (in-ns 'dbx) (clojure.core/use 'clojure.core)" Nowadays is :repl-options {:init-ns foo.bar} . See https://github.com/technomancy/leiningen/blob/master/sample.project.clj Abimaran Kugathasan If you

Is there something like python's interactive REPL mode, but for Java? So that I can, for example, type InetAddress.getAllByName( localHostName ) in a window, and immediately get results, without all this public static void nightmare() thing? edit Since Java 9 there's JShell Original answer follows You can also use Groovy Console . It is an interactive console where you can do what you want. Since Groovy also includes classes from the core java platform, you'll be able to use those classes as well. It looks like this: Eclipse has a feature to do this, although it's not a loop. It's called a

In the Swift REPL, how to import (a.k.a. load, evaluate, require) a typical text *.swift file? I want to use the code from this file: ~/src/Foo.swift Syntax like this doesn't work: import ~/src/Foo.swift For comparison: An equivalent solution in the Swift REPL for a framework is: import Foundation An equivalent solution in the Ruby REPL for a *.ruby file is: require "~/src/foo" These are similar questions that are /not/ what I'm asking: How to use/make a Swift command-line script, executable, module, etc. How to use/make an XCode playground, project, library, framework, etc. How to launch the

I use Emacs 24.2. I've installed js-comint and js-mode from MELPA , executed run-js , and now in REPL instead of > sign i have this gibberish: ^[[1G> ^[[0K^[[3G The REPL itself in Inferior Javascript mode works just fine, just the > sign is changed. If you enter unfinished expression, it even prints ^[[1G... ^[[0K^[[5G . The ^[ are system characters, that are not copied with copy-paste, i add them for you to have an idea. In my init-file: (require 'js-comint) (setq inferior-js-program-command "nodejs") In terminal calling nodejs produces working REPL. Why prompt behaves this way? What should i

What is the preferred way of reloading functions defined in a Clojure file without having to restart the REPL. Right now, in order to use the updated file I have to: edit src/foo/bar.clj close the REPL open the REPL (load-file "src/foo/bar.clj") (use 'foo.bar) In addition, (use 'foo.bar :reload-all) does not result in required effect, which is evaluating the modified bodies of functions and returning new values, instead of behaving as the source haven't changed at all. Documentation: load-file use Or (use 'your.namespace :reload) papachan There is also an alternative like using tools.namespace