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Clojure parser for Emacs Lisp

parseclj is an Emacs Lisp library for parsing Clojure code and EDN data. It supports several input and output formats, all powered by the same shift-reduce parser function.

Take a look at the design document for more details.

parseclj is in alpha state right now, its API might be subject to change.

Installation

Available on the major package.el community maintained repos - MELPA Stable and MELPA repos.

MELPA Stable is the recommended repo as it has the latest stable version. MELPA has a development snapshot for users who don't mind (infrequent) breakage but don't want to run from a git checkout.

You can install parseclj using the following command:

M-x package-install [RET] parseclj [RET]

or if you'd rather keep it in your dotfiles:

(unless (package-installed-p 'parseclj)
  (package-install 'parseclj))

If the installation doesn't work try refreshing the package list:

M-x package-refresh-contents

Usage

parseclj contains function that return an AST that, for example, given as input (1 2 [:a :b :c]), it looks like this:

((:node-type . :root)
 (:position . 1)
 (:children ((:node-type . :list)
             (:position . 1)
             (:children ((:node-type . :number)
                         (:position . 2)
                         (:form . "1")
                         (:value . 1))
                        ((:node-type . :number)
                         (:position . 4)
                         (:form . "2")
                         (:value . 2))
                        ((:node-type . :vector)
                         (:position . 6)
                         (:children ((:node-type . :keyword)
                                     (:position . 7)
                                     (:form . ":a")
                                     (:value . :a))
                                    ((:node-type . :keyword)
                                     (:position . 10)
                                     (:form . ":b")
                                     (:value . :b))
                                    ((:node-type . :keyword)
                                     (:position . 13)
                                     (:form . ":c")
                                     (:value . :c))))))))

In order to use any of these functions, you first need to require it:

(require 'parseclj)

And then you will have the following functions at your disposal:

  • parseclj-parse-clojure &rest string-and-options

    When no arguments, parses Clojure source code into an AST and returns it. When given a string as a first argument, parses it and returns the corresponding AST.

    A list of options can be passed down to the parsing process, particularly:

    • :lexical-preservation: a boolean value to retain whitespace, comments, and discards. Defaults to nil.
    • :fail-fast: a boolean value to raise an error when encountering invalid syntax. Defaults to t.

    Examples:

    (parseclj-parse-clojure) ;; will parse clojure code in the current buffer and return an AST
    (parseclj-parse-clojure "(1 2 3)")  ;; => ((:node-type . :root) ... )
    (parseclj-parse-clojure :lexical-preservation t) ;; will parse clojure code in current buffer preserving whitespaces, comments and discards

    Note: there's an open issue to extend this API to parse clojure code within some boundaries of a buffer. Pull requests are welcome.

  • parseclj-unparse-clojure ast

    Transform the given AST into Clojure source code and inserts it into the current buffer.

  • parseclj-unparse-clojure-to-string ast

    Transfrom the given AST into Clojure source code and returns it as a string.

License

© 2017-2021 Arne Brasseur and contributors.

Distributed under the terms of the GNU General Public License 3.0 or later. See LICENSE.