ikitommi / edamame

EDN parser with location metadata and pluggable dispatch table.

Edamame

EDN parser with location metadata and pluggable dispatch table.

Rationale

This library can be useful when:

• You want to include locations in feedback about EDN files.
• You want to parse Clojure-like expressions and want to add support for unsupported EDN characters.

This library came out of sci, a small Clojure interpreter.

Features

• Parse EDN values with location as metadata.
• Pluggable dispatch table to extend EDN.

This library works with:

• Clojure on the JVM
• ClojureScript

Usage

(require '[edamame.core :refer [parse-string]])

Locations are attached as metadata:

(def s "
[{:a 1}
 {:b 2}]")
(map meta (parse-string s))
;;=>
({:row 2, :col 2}
 {:row 3, :col 2})

(->> "{:a {:b {:c [a b c]}}}"
     parse-string
     (tree-seq coll? #(if (map? %) (vals %) %))
     (map meta))
;;=>
({:row 1, :col 1}
 {:row 1, :col 5}
 {:row 1, :col 9}
 {:row 1, :col 13}
 {:row 1, :col 14}
 {:row 1, :col 16}
 {:row 1, :col 18})

Dispatch on a character, even if it's unsupported in EDN:

(parse-string "@foo" {:dispatch {\@ (fn [val] (list 'deref val))}})
;;=> (deref foo)

Dispatch on dispatch characters:

(parse-string "#\"foo\"" {:dispatch {\# {\" #(re-pattern %)}}})
;;=> #"foo"

(parse-string "#(inc 1 2 %)" {:dispatch {\# {\( (fn [expr] (read-string (str "#" expr)))}}})
;;=> (fn* [p1__11574#] (inc 1 2 p1__11574#))

Test

script/test/jvm
script/test/node
script/test/all

Status

Experimental. Breaking changes are expected to happen at this phase.

Installation

Use as a dependency:

Credits

The code is largely inspired by rewrite-clj and derived projects.

License

Copyright © 2019 Michiel Borkent

Distributed under the Eclipse Public License 1.0. This project contains code from Clojure and ClojureScript which are also licensed under the EPL 1.0. See LICENSE.