When DrRacket starts up, and the language is set to Determine Language From Source (aka not the student languages), DrRacket starts every new file with a default line:
#lang racket
Normally this is good because its a nice default for writing quick scripts, throw away examples, etc. And if you want a more specific language, say racket/base, its easy enough to go change it.
However, the racket language lacks a few features that I find really nice for quick scratch work. The agile language however does have many of the libraries that I want included by default. However, replacing the racket with agile is just as annoying as writing out (require syntax/parse/define).
Is there a way I can tell DrRacket to change my default #lang? That way new files will start with:
#lang agile
Yes, it actually is possible to change the default language DrRacket uses for new files.
To change this setting go to: Languages -> Choose Language -> Show Details
and at the bottom right corner you will see Automatic #lang line. Change that to whatever you want and that will be the first line of new Racket files. Click Ok and your preference is set.
Related
Just FYI, I am new to the .emacs file.
I would lik to set up my .emacs file to auto-indent and auto-pair a certain way to make writing code a little faster. I have found some info as to how to do these things independently but I'm not sure how to put it all together for the emacs version that I have. Ultimately, I would like to set up these definitions specific to which ever language I am coding in. Just to get me started I will use java as an example.
Obviously auto-pairing for ", (, ' are pretty straigforward. I would just like it to auto insert a closing ", ), ' and place the cursor in the middle.
For {, I would like it auto insert two newlines and the closing } whith the cursor in the middle.
Example
while (true) {
<--- cursor would be here with auto-indent of 2 spaces
}
I would also like this to work for nested curly braces which the appropriate indentation.
Example
while(true) {
if (...) {
}
}
Here is what I have so far in my .emacs file:
(defun java-autoindent ()
(when (and (eq major-mode 'java-mode) (looking-back "[{;]"))
(newline-and-indent)))
(add-hook 'post-self-insert-hook 'java-autoindent)
Obviously this just inserts a line and auto indents, but I also want the closed } to be included on the line below. I also tried using electric-pair but that didn't work.
My wish list may be a little unrealistic. I'm not even sure that this is possible, but I would be happy with the closest that I could get.
Any help to get me going in the right direction would be greatly appreciated.
Emacs defines modes for each type of language you code in. Some modes are derived from others and there is a mode called prog-mode which most programming modes are derived from.
The mode for a language is where things like indentation are defined because these tend to be language specific. The rules for indentation can be quite complicated, which is why people often use a mode with similar indentation style as the parent and derive a new mode from that.
Have a look at modes and derived mode in the emacs elisp manual.
With respect to adding matching/closing delimiters, have a look at electric-pair-mode (I think it was in emacs 24.4 - I'm running 25 and forget when it was introduced).
With respect to your requirement to enter some code, some newlines and position the cursor in a specific place, you probably want to look at one of emacs' template solutions. yasnippet is a popular choice and it is easy to define new templates in it. There are also many existing packaged yasnippet templates you can download/install. If you don't like yasnippet, google emacs template and have a look there are quitre a few frameworks.
I've recently switched from using Eclipse to emacs. I'm trying to find a way to emulate eclipse's Ctrl-Shft-r functionality which lets you type in a file name and it begins showing all files in the current workspace that begin with the string you are typing.
C-x C-f seems to handle just tab-completion in the current directory, whereas Eclipse's functionality looked through all sub-directories to find matching files.
I'm looking for something (maybe there's a plugin that does this) that allows you to type the name of folder to look in, and then a partial file and returns back the results in a buffer. Possibly that uses auto-complete to list off matching files with their full paths.
First of all, steer clear of vanilla find-file function (that's the interactive function that is run when you hit C-x C-f). It is very limited, it forces you to hit TAB all the time, and the first thing most people do when switching to emacs is replace find-file with something more powefull.
There're a number of alternatives. ido-mode is one, helm is another. The former is light-weight, fast and comes built-in with emacs. The latter is immensely powerful and strives to be fast, too.
Second of all, there're two ways a recursive file search can usually be done:
directory search - that's when you just search a directory, no surprises here;
project search - that's when you setup a project your're working on, thus making emacs aware of which files are of interest to you right now.
For directory search, ido-find-file and helm-find-file are both viable options. Ido does its search automatically when you pause typing; helm uses (C-u) M-g s to activate grep. See this SO question for more info.
For project search, you need a library to manage your projects. Projectile is great for that. Set it up and use C-c p f or C-c p F to list files in current or all of your projects, respectively. Oh, and projectile uses ido by default, but there is helm support, too.
You're looking for projectile which indexes your project's files. I used it for a while but have recently switched to using helm-recentf
(global-set-key "\C-x\ \C-r" 'helm-recentf)
I have recent files set to a large number. Pretty much anything I've ever opened is a few keystrokes away. This even doubles up as a handy way to switch buffers.
(require 'recentf)
(setq recentf-auto-cleanup 'never)
(recentf-mode 1)
(setq recentf-max-saved-items 200)
I'm tinkering about switching my IDE to emacs. (I'm still an emacs newbie.)
The problem is that I customized my IDE quite well and I'd regret to leave my helpers behind.
Let me explain:
Shows the current open files/buffers, allows fast switching with a hotkey (C-1, C-2, ...)
Shows the most recent texts on the "clipboard" or inserted by complete (no. 4), text insertable with a hotkey (C-b 1, C-b 2, ...) Last inserted shown in bold, insertable with C-`
The last inserted complete (no. 4) text, insertable with M-`
Autocomplete-ish list, gathered from all open files, regardless of their type with some magical logic. text insertable with a hotkey (M-1, M-2, ...)
I guess emacs has such features, but I'm a visual type I'd like to see what I have available.
Of course actual hotkeys don't matter much, but as you see having all that info visible makes it easy to hit the spot with the least keypresses.
My pain is that there is a plethora of emacs extensions providing various features, checking all seems to take a lifetime.
My question is:
are there any emacs extensions to achieve similar looks and behavour?
as I'm a programmer, which extensions could I take as a base to assemble something like this?
Thanks!
Elaborating a bit more:
I’m a python dev, so most of the code I’m writing is python. Add some HTML JS CSS XML to the picture.
One important thing is that completion needs to work across filetype boundaries, because python / HTML(template) / XML(config) / doctest identifiers are cross-referenced. It’s a huge pain with some IDEs that completion works only for python filetypes.
I have a lot of same named files but in different folders, like init.py, configure.zcml, etc. It seems to be a pain to switch between those by filename.
Better said that’s a list of recently inserted text. To be reused by the fewest keys as possible. Usually when coding I’m reusing the same identifiers/whatever within the same task. So it’s handy to have them listed instead having to retype the starting x chars to get completion again.
Usually best use of this feature is when changing/refactoring code. Like adding one more extra feature and the identifier is needed several times over the place.
TL;DR
Learn keyboard macros. Learn yasnippet.
Autocomplete mode is probably similar to what you have.
Get acquainted with emacs kill-ring before trying to change it, it wants to be your friend. Then you'll know what to look for when you DO want to change it.
Long Version
Shows the current open files/buffers, allows fast switching with a hotkey (C-1, C-2, ...)
You have three options for this.
My personal preference is to have all source files open at all times. So I don't need a visual list of open buffers. Whenever I want to switch to a file I hit C-= (which I've bound to iswitchb-buffer) and type a couple of unique letters. It's common to constantly switch between the same two buffers so I also bound C-backspace to previous-buffer.
Another option I can recommend is tabbar. It's not exactly like your setup, but it displays a list of open buffers (just like webpages in a browser) and it has functions for cycling through the tabs, so it shouldn't be hard to reproduce your C-number key bindings.
You could use speedbar or ecb. They would be the most similar to your current visual configuration, but I'd argue the other options are more efficient.
Shows the most recent texts on the "clipboard" or inserted by complete (no. 4), text insertable with a hotkey (C-b 1, C-b 2, ...) Last inserted shown in bold, insertable with...
I see you've sort of mixed the clipboard with completion history. When it comes to emacs, yasnippet and autocomplete are just so good you're better off going with them for completion (see below).
Emacs clipboard is called the kill-ring. I'm sure you know of C-y and M-y, so you can always recover anything you've cut in the past. Unfortunately, I don't know of any packages that constantly display the kill ring or allow you to yank a specific part of it (though that shouldn't be too hard to write), but at least you know what to search for (kill-ring).
The last inserted complete (no. 4) text, insertable with M-`
I'll be honest, I don't see that much use in this. If you have to repetitively insert text, you should learn keyboard macros. In fact, you should learn keyboard macros anyway, they're the first reason I got hooked to emacs.
Autocomplete-ish list, gathered from all open files, regardless of their type with some magical logic. text insertable with a hotkey (M-1, M-2, ...)
Emacs had many great completion options. In your case, the best one is probably autocomplete-mode. It pops-up completion options (much like your separate completions window), and I think it allows for quick selection of a specific option (like your M-number shortcuts). Also it has several different ways of deciding which completions to offer you (it calls them "sources") and one of them is to gather from all buffers.
In addition to that you have yasnippet, and I couldn't possibly recommend it enough. Seriously. Learning to use it and writing your own snippets will change the way you write code. You'll become a mage whose fingers produce pages of code flowing through your screen in blazing speeds. Use yasnippet!
Once you have it configured, every 3 or 4 keys you press will generate a line (or more) of code for you.
After all that, if you still miss something from your previous editor you'll write it yourself. :-)
Your setup looks exactly like https://github.com/emacsmirror/ecb.
To me at least, since I don't use side-bars:)
You should take a look at the extension speedbar. I have installed this extension, but I rarely use it even for a very large project.
I've just found speedbar and it's a wonderfully useful tool. I really like how it can drill into (python) files to show me a list of classes, methods and functions.
Is there any way I can get speedbar to auto-expand the tree of class/function references for the file in the currently active buffer?
It would be a bonus too if I could just expand to where the current cursor is; for instance, if the cursor was located in the foo function of the bar class, speedbar would expand to myfile.py > class bar > foo.
There is no canned solution for what you are asking about. Speedbar does, of course, know how to do it, but you will need to write a new command to do it.
I'll guess you might be interested in ECB, which can serve a similar function. It breaks the side window into multiple parts, and one of the windows does follow the cursor around in the list of tags. I'll guess this is what you want.
in gedit it's possible to define so-called "snippets" for simpler input.
For example, there is a snippet while. This means: If you type while -> (-> stands for tab key). And gedit automatically converts it to the following (including correct indentation):
while (condition){
}
In vim (in conjunction with latex-suite) I saw the following: If you type (, vim inserts just a (. If you type ( a second time, vim automatically converts it to \left( \right).
I found abbrev-mode but this mode doesn't place the cursor properly (i.e. between parentheses or inside the while loop).
I managed to create custom emacs keybindings/macros that do just the same (without having to press the tab key), so I know it's possible.
However, is there already and package where you can define such "snippets" without much effort? Or are there even any serious reasons not to use such things?
See yasnippet. It provides snippets for most major languages, and it is easy to add new ones or modify the old ones.
Yes, yasnippet is probably the way to go. But make sure you learn the major mode you're using for your editing - when writing in LaTeX, learn auctex. Major modes can contain functionality that makes some snippets pointless, and do the same thing even better. So instead of using a begin/end-snippet in a LaTeX buffer, try C-c C-e in auctex. Etc :)
Don't forget abbrev-mode.