# dash.el [![Build Status](https://secure.travis-ci.org/magnars/dash.el.png)](http://travis-ci.org/magnars/dash.el) A modern list api for Emacs. No 'cl required. ## Installation It's available on [marmalade](http://marmalade-repo.org/) and [Melpa](http://melpa.milkbox.net/): M-x package-install dash Or you can just dump `dash.el` in your load path somewhere. If you want the function combinators, then also: M-x package-install dash-functional ## Using in a package Add this to the big comment block at the top: ;; Package-Requires: ((dash "2.10.0")) To get function combinators: ;; Package-Requires: ((dash "2.10.0") (dash-functional "1.2.0") (emacs "24")) ## Syntax highlighting of dash functions Font lock of dash functions in emacs lisp buffers is now optional. Include this in your emacs settings to get syntax highlighting: (eval-after-load "dash" '(dash-enable-font-lock)) ## Functions All functions and constructs in the library are prefixed with a dash (-). There are also anaphoric versions of functions where that makes sense, prefixed with two dashes instead of one. While `-map` takes a function to map over the list, you can also use the anaphoric form with double dashes - which will then be executed with `it` exposed as the list item. Here's an example: ```el (-map (lambda (n) (* n n)) '(1 2 3 4)) ;; normal version (--map (* it it) '(1 2 3 4)) ;; anaphoric version ``` of course the original can also be written like ```el (defun square (n) (* n n)) (-map 'square '(1 2 3 4)) ``` which demonstrates the usefulness of both versions. [[ function-list ]] [[ function-docs ]] ## Contribute Yes, please do. Pure functions in the list manipulation realm only, please. There's a suite of tests in `dev/examples.el`, so remember to add tests for your function, or I might break it later. You'll find the repo at: https://github.com/magnars/dash.el Run the tests with ./run-tests.sh Create the docs with ./create-docs.sh I highly recommend that you install these as a pre-commit hook, so that the tests are always running and the docs are always in sync: cp pre-commit.sh .git/hooks/pre-commit Oh, and don't edit `README.md` directly, it is auto-generated. Change `readme-template.md` or `examples-to-docs.el` instead. ## Changelist ### From 2.9 to 2.10 - Add `-let` destructuring to `-if-let` and `-when-let` (Fredrik Bergroth) ### From 2.8 to 2.9 - Add `-let`, `-let*` and `-lambda` with destructuring - Add `-tree-seq` and `-tree-map-nodes` - Add `-non-nil` - Add `-fix` - Add `-fixfn` (dash-functional 1.2) - Add `-copy` (Wilfred Hughes) ### From 2.7 to 2.8 - Add `-butlast` ### From 2.6 to 2.7 - `-zip` now supports more than two lists (Steve Lamb) - Add `-cycle` , `-pad` , `-annotate` , `-zip-fill` (Steve Lamb) - Add `-table`, `-table-flat` (finite cartesian product) - Add `-flatten-n` - `-slice` now supports "step" argument - Add functional combinators `-iteratefn`, `-prodfn` - Add `-replace`, `-splice`, `-splice-list` which generalize `-replace-at` and `-insert-at` - Add `-compose`, `-iteratefn` and `-prodfn` (dash-functional 1.1) ### From 2.5 to 2.6 - Add `-is-prefix-p`, `-is-suffix-p`, `-is-infix-p` (Matus Goljer) - Add `-iterate`, `-unfold` (Matus Goljer) - Add `-split-on`, `-split-when` (Matus Goljer) - Add `-find-last-index` (Matus Goljer) - Add `-list` (Johan Andersson) ### From 2.4 to 2.5 - Add `-same-items?` (Johan Andersson) - A few bugfixes ### From 2.3 to 2.4 - Add `-snoc` (Matus Goljer) - Add `-replace-at`, `-update-at`, `-remove-at`, and `-remove-at-indices` (Matus Goljer) ### From 2.2 to 2.3 - Add tree operations (Matus Goljer) - Make font-lock optional ### From 2.1 to 2.2 - Add `-compose` (Christina Whyte) ### From 2.0 to 2.1 - Add indexing operations (Matus Goljer) ### From 1.8 to 2.0 - Split out `dash-functional.el` (Matus Goljer) - Add `-andfn`, `-orfn`, `-not`, `-cut`, `-const`, `-flip` and `-on`. (Matus Goljer) - Fix `-min`, `-max`, `-min-by` and `-max-by` (Matus Goljer) ### From 1.7 to 1.8 - Add `-first-item` and `-last-item` (Wilfred Hughes) ### From 1.6 to 1.7 - Add `-rotate` (Matus Goljer) ### From 1.5 to 1.6 - Add `-min`, `-max`, `-min-by` and `-max-by` (Johan Andersson) ### From 1.4 to 1.5 - Add `-sum` and `-product` (Johan Andersson) ### From 1.3 to 1.4 - Add `-sort` - Add `-reduce-r` (Matus Goljer) - Add `-reduce-r-from` (Matus Goljer) ### From 1.2 to 1.3 - Add `-partition-in-steps` - Add `-partition-all-in-steps` ### From 1.1 to 1.2 - Add `-last` (Matus Goljer) - Add `-insert-at` (Emanuel Evans) - Add `-when-let` and `-if-let` (Emanuel Evans) - Add `-when-let*` and `-if-let*` (Emanuel Evans) - Some bugfixes ## Contributors - [Matus Goljer](https://github.com/Fuco1) contributed lots of features and functions. - [Takafumi Arakaki](https://github.com/tkf) contributed `-group-by`. - [tali713](https://github.com/tali713) is the author of `-applify`. - [Víctor M. Valenzuela](https://github.com/vemv) contributed `-repeat`. - [Nic Ferrier](https://github.com/nicferrier) contributed `-cons*`. - [Wilfred Hughes](https://github.com/Wilfred) contributed `-slice`, `-first-item` and `-last-item`. - [Emanuel Evans](https://github.com/shosti) contributed `-if-let`, `-when-let` and `-insert-at`. - [Johan Andersson](https://github.com/rejeep) contributed `-sum`, `-product` and `-same-items?` - [Christina Whyte](https://github.com/kurisuwhyte) contributed `-compose` - [Steve Lamb](https://github.com/steventlamb) contributed `-cycle`, `-pad`, `-annotate`, `-zip-fill` and an n-ary version of `-zip`. - [Fredrik Bergroth](https://github.com/fbergroth) made the `-if-let` family use `-let` destructuring and improved script for generating documentation. - [Mark Oteiza](https://github.com/holomorph) contributed the script to create an info manual. - [Vasilij Schneidermann](https://github.com/wasamasa) contributed `-some`. - [William West](https://github.com/occidens) made `-fixfn` more robust at handling floats. Thanks! ## License Copyright (C) 2012-2014 Magnar Sveen Authors: Magnar Sveen Keywords: lists This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see .