feat: add syntax highlighting in the REPL

lib/node_modules/@stdlib/repl/lib/ansi_colors.js

@@ -0,0 +1,58 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2024 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MAIN //
+
+/**
+* Table mapping generic color names to their ANSI color codes.
+*
+* @private
+* @name ANSI
+* @type {Object}
+*/
+var ANSI = {
+	// Original colors:
+	'black': '\u001b[30m',
+	'red': '\u001b[31m',
+	'green': '\u001b[32m',
+	'yellow': '\u001b[33m',
+	'blue': '\u001b[34m',
+	'magenta': '\u001b[35m',
+	'cyan': '\u001b[36m',
+	'white': '\u001b[37m',
+
+	// Bright colors:
+	'brightBlack': '\u001b[90m',
+	'brightRed': '\u001b[91m',
+	'brightGreen': '\u001b[92m',
+	'brightYellow': '\u001b[93m',
+	'brightBlue': '\u001b[94m',
+	'brightMagenta': '\u001b[95m',
+	'brightCyan': '\u001b[96m',
+	'brightWhite': '\u001b[97m',
+
+	// Reset colors:
+	'reset': '\u001b[0m'
+};
+
+
+// EXPORTS //
+
+module.exports = ANSI;

lib/node_modules/@stdlib/repl/lib/complete_expression.js

@@ -54,7 +54,7 @@
 * @param {string} expression - expression to complete
 * @returns {string} filter
 */
 function complete( out, context, expression ) {
 	var filter;
 	var script;
 	var node;
@@ -74,7 +74,7 @@
 	ast = parse( expression, AOPTS );
 
 	debug( 'Resolving local scopes within the AST.' );
-	ast = resolveLocalScopes( ast );
+	resolveLocalScopes( ast );
 
 	// Get the last program top-level AST "node":
 	debug( 'Number of statements: %d', ast.body.length );

lib/node_modules/@stdlib/repl/lib/main.js

@@ -63,6 +63,7 @@
 var completerFactory = require( './completer.js' );
 var PreviewCompleter = require( './completer_preview.js' );
 var AutoCloser = require( './auto_close_pairs.js' );
+var SyntaxHighlighter = require( './syntax_highlighter.js' );
 var ALIAS_OVERRIDES = require( './alias_overrides.js' );
 var SETTINGS = require( './settings.js' );
 var SETTINGS_VALIDATORS = require( './settings_validators.js' );
@@ -270,11 +271,14 @@
 	// Initialize a preview completer:
 	setNonEnumerableReadOnly( this, '_previewCompleter', new PreviewCompleter( this._rli, this._completer, this._ostream, this._settings.completionPreviews ) );
 
+	// Initialize a syntax-highlighter:
+	setNonEnumerableReadOnly( this, '_syntaxHighlighter', new SyntaxHighlighter( this, this._ostream ) );
+
 	// Cache a reference to the private readline interface `ttyWrite` to allow calling the method when wanting default behavior:
 	setNonEnumerableReadOnly( this, '_ttyWrite', this._rli._ttyWrite );
 
 	// Overwrite the private `ttyWrite` method to allow processing input before a "keypress" event is triggered:
 	this._rli._ttyWrite = beforeKeypress; // WARNING: overwriting a private property
 
 	// Add event listeners:
 	this._rli.on( 'close', onClose );
@@ -294,9 +298,9 @@
 	// Write a welcome message:
 	this._wstream.write( opts.welcome );
 
 	// TODO: check whether to synchronously initialize a REPL history file
 
 	// TODO: check whether to synchronously initialize a REPL log file
 
 	// Check whether to load and execute a JavaScript file (e.g., prior REPL history) upon startup...
 	if ( opts.load ) {
@@ -334,6 +338,7 @@
 	*/
 	function onKeypress( data, key ) {
 		var autoClosed;
+
 		if ( key && key.name === 'tab' ) {
 			return;
 		}
@@ -343,6 +348,9 @@
 		if ( autoClosed ) {
 			self._previewCompleter.clear();
 		}
+		if ( self._isTTY ) {
+			self._syntaxHighlighter.onKeypress();
+		}
 		self._previewCompleter.onKeypress( data, key );
 	}
 
@@ -445,9 +453,9 @@
 		// Update the internal command history buffer: [..., <id>, <cmd>, <success>, ...]
 		self._history.push( self._count, cmd, success );
 
 		// TODO: if successful and if necessary, (asynchronously?) write the command to a history file (question: do we only want to write successful commands to the history file? maybe we need to option for limiting to successful commands?)
 
 		// TODO: if necessary, (asynchronously?) write the command and result to a log file (JSON serialization?)
 	}
 }
 
@@ -671,7 +679,7 @@
 
 	// Before creating a new execution context in a non-sandboxed environment, remove current workspace variables in order to allow garbage collection and avoid memory leaks (e.g., variables/functions declared during a REPL session which might remain bound to the environment `global` after clearing a REPL):
 	if ( this._sandbox === false ) {
 		// WARNING: in a non-sandboxed environment, if a global variable is externally introduced during a REPL session (i.e., introduced via a mechanism outside of the REPL environment), we will delete that global variable, which means the following logic may introduce unintended side-effects for this particular edge case (e.g., application code may expect the presence of the subsequently deleted global variable). While not ideal, (a) user applications should not be introducing globals to begin with and (b) the probability of a user running a REPL session, a user clearing that REPL session, AND a global variable being introduced between starting a REPL and clearing the REPL should be negligible.
 		tmp = this._context.vars();
 		for ( i = 0; i < tmp.length; i++ ) {
 			if ( isConfigurableProperty( this._context, tmp[ i ] ) ) {
@@ -1064,9 +1072,9 @@
 	// Clear the command queue:
 	this._queue.clear();
 
 	// TODO: ensure REPL history is saved (flushed) to file before closing the REPL (see https://github.com/nodejs/node/blob/b21e7c7bcf23a2715951e4cd96180e4dbf1dcd4d/lib/repl.js#L805)
 
 	// TODO: ensure REPL log is saved (flushed) to file before closing the REPL
 
 	nextTick( onTick );
 
@@ -1089,7 +1097,7 @@
 
 		// If this is a non-sandboxed REPL, remove global variables/properties which were introduced during context creation and by a user during a REPL session...
 		if ( self._sandbox === false ) {
 			// WARNING: in a non-sandboxed environment, if a global variable is externally introduced during a REPL session (i.e., introduced via a mechanism outside of the REPL environment), we will delete that global variable, which means the following logic may introduce unintended side-effects for this particular edge case (e.g., application code may expect the presence of the subsequently deleted global variable). While not ideal, (a) user applications should not be introducing globals to begin with and (b) the probability of a user running a REPL session, a user closing that REPL session, AND a global variable being introduced between starting a REPL and closing the REPL should be negligible.
 			tmp = self._context.vars(); // current workspace variables
 			for ( i = 0; i < tmp.length; i++ ) {
 				if ( isConfigurableProperty( self._context, tmp[ i ] ) ) {

lib/node_modules/@stdlib/repl/lib/resolve_globals.js

@@ -76,7 +76,7 @@ function resolveGlobals( ast ) {
 	globals = [];
 
 	// Resolve local scopes:
-	ast = resolveLocalScopes( ast );
+	resolveLocalScopes( ast );
 
 	// Define callbacks for relevant AST nodes:
 	visitors = {