Add commands to run Emacs Lisp from Atom

Author: Alhadis

index.js

@@ -0,0 +1,141 @@
+"use strict";
+
+const childProcess = require("child_process");
+const path = require("path");
+
+
+class EmacsLisp{
+	
+	activate(){
+		const target = "atom-text-editor";
+		
+		atom.commands.add(target, "language-emacs-lisp:run-selection", e => {
+			const text = this.getSelection();
+			if(text && !/^\s+$/.test(text))
+				this.eval(text)
+					.then(output  => this.showOutput(output))
+					.catch(output => this.showOutput(output, true));
+		});
+		
+		atom.commands.add(target, "language-emacs-lisp:run-file", e => {
+			const ed = atom.workspace.getActiveTextEditor();
+			if(ed) this.runFile(ed.getPath())
+				.then(output  => this.showOutput(output))
+				.catch(output => this.showOutput(output, true));
+		});
+	}
+	
+	
+	/**
+	 * Evaluate a string of Emacs Lisp code.
+	 *
+	 * Returns a {Promise} that resolves to the stringified output.
+	 *
+	 * @public
+	 * @example eval("(+ 5 5)") -> "10"
+	 * @param {String} text
+	 * @return {Promise}
+	 */
+	eval(text){
+		return new Promise((resolve, reject) => {
+			const emacs = childProcess.spawn("emacs", [
+				"--batch",
+				"--eval",
+				`(message "%s" ${text})`
+			]);
+			
+			let output = "";
+			emacs.stderr.on("data", data => {
+				if(data) output += data.toString();
+			});
+			
+			emacs.on("close", code => {
+				output = output.replace(/^\n+|\n+$/g, "");
+				code !== 0
+					? reject(output)
+					: resolve(output);
+			})
+		});
+	}
+	
+	
+	/**
+	 * Run a Lisp file in Emacs.
+	 *
+	 * Returns a {Promise} with the script's output, if any.
+	 *
+	 * @public
+	 * @param {String} file - Path to file
+	 * @return {Promise}
+	 */
+	runFile(file){
+		return new Promise((resolve, reject) => {
+			const emacs = childProcess.spawn("emacs", ["--script", file]);
+			
+			let output = "";
+			emacs.stderr.on("data", data => {
+				if(data) output += data.toString();
+			});
+			
+			emacs.on("close", code => {
+				output = output.replace(/^\n+|\n+$/g, "");
+				code !== 0
+					? reject(output)
+					: resolve(output);
+			})
+		});
+	}
+	
+	
+	/**
+	 * Show output in the notifications area.
+	 *
+	 * @param {String} text
+	 * @param {Boolean} error
+	 * @private
+	 */
+	showOutput(text, error = false){
+		const msg = "**Emacs:** " + text;
+		const opt = {dismissable: true};
+		error
+			? atom.notifications.addError(msg, opt)
+			: atom.notifications.addInfo(msg, opt);
+	}
+
+	
+	/**
+	 * Retrieve an editor's currently-selected text.
+	 *
+	 * If nothing's selected, the scope enclosing the cursor's current
+	 * position is selected and returned instead.
+	 *
+	 * @param {TextEditor} ed - Defaults to current editor
+	 * @private
+	 */
+	getSelection(ed){
+		ed = ed || atom.workspace.getActiveTextEditor();
+		if(!ed) return;
+		let text = ed.getSelectedText();
+		
+		/** If the user hasn't made a selection, make one for 'em */
+		if(!text){
+			if(atom.packages.activePackages["bracket-matcher"]){
+				atom.commands.dispatch(ed.editorElement, "bracket-matcher:select-inside-brackets");
+				
+				/** Select containing brackets too */
+				let range = ed.getSelectedBufferRange();
+				--range.start.column;
+				++range.end.column;
+				ed.setSelectedBufferRange(range);
+			}
+			
+			/** Fallback if bracket-matcher isn't available */
+			else ed.selectWordsContainingCursors();
+			
+			text = ed.getSelectedText();
+		}
+		return text;
+	}
+}
+
+module.exports = new EmacsLisp();

tests/run.el

@@ -0,0 +1 @@
+(message "%s" (+ 2 2))