Add emoji support

Author: kgryte

lib/node_modules/@stdlib/repl/presentation/README.md

@@ -227,6 +227,18 @@ For example,
 
 ```
 
+#### Emoji
+
+To include an [emoji][@stdlib/datasets/emoji], insert the relevant [emoji code][@stdlib/datasets/emoji-code-picto]. For example,
+
+```text
+
+:books: :grinning: :+1: :man: :woman:
+
+```
+
+Note, however, that [emoji][@stdlib/datasets/emoji] support is **limited** to [emoji][@stdlib/datasets/emoji] which are **two** columns wide. Accordingly, not all [emoji][@stdlib/datasets/emoji] are supported.
+
 </section>
 
 <!-- /.intro -->
@@ -1470,6 +1482,10 @@ $ stdlib-repl-presentation ./path/to/presentation.txt
 
 [@stdlib/repl]: https://github.com/stdlib-js/stdlib
 
+[@stdlib/datasets/emoji]: https://github.com/stdlib-js/stdlib
+
+[@stdlib/datasets/emoji-code-picto]: https://github.com/stdlib-js/stdlib
+
 </section>
 
 <!-- /.links -->

lib/node_modules/@stdlib/repl/presentation/examples/presentation.txt

@@ -16,7 +16,7 @@ Speaker notes.
 
 ---
 
-| standard library for JavaScript and Node.js
+| :books: standard library for JavaScript and Node.js :books:
 \s
 
 --

lib/node_modules/@stdlib/repl/presentation/lib/emoji.js

@@ -0,0 +1,101 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2019 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';
+
+// MODULES //
+
+var replace = require( '@stdlib/string/replace' );
+var hasOwnProp = require( '@stdlib/assert/has-own-property' );
+var table = require( '@stdlib/datasets/emoji-code-picto' );
+
+
+// VARIABLES //
+
+var TABLE = table();
+
+
+// MAIN //
+
+/**
+* Replaces emoji codes with rendered emoji in a line of slide text.
+*
+* ## Notes
+*
+* -   The input line object is mutated.
+*
+* @private
+* @param {Object} line - line
+* @returns {Object} rendered line
+*/
+function emoji( line ) {
+	var RE_EMOJI_CODE;
+	var len;
+
+	// Create a regular expression for matching emoji codes (code schema: `:<short_name>[::<modifier>[, <modifier>[, ...]]]`):
+	RE_EMOJI_CODE = /:([\w+\-]+)(?::{2}([\w+\-,\s]+))?:/g; // eslint-disable-line no-useless-escape
+
+	// Initialize a length adjustment factor:
+	len = 0;
+
+	// Replace emoji codes with rendered emojis:
+	line.text = replace( line.text, RE_EMOJI_CODE, replacer );
+
+	// Update the effective line length:
+	line.length += len;
+
+	// Return the rendered line:
+	return line;
+
+	/**
+	* Callback invoked for each match.
+	*
+	* @private
+	* @param {string} match - matched substring
+	* @param {string} p1 - first string found by a parenthesized capture group
+	* @param {(string|void)} p2 - second string found by a parenthesized capture group
+	* @returns {string} replacement string
+	*/
+	function replacer( match, p1, p2 ) {
+		var code;
+		var out;
+
+		// Reconstitute the emoji code in order to normalize the code string:
+		code = ':' + p1 + ':';
+		if ( p2 ) {
+			p2 = p2.split( /,\s*/ ).join( ', ' ); // normalize any modifiers by ensuring consistent modifier spacing
+			code += ':' + p2 + ':';
+		}
+		if ( hasOwnProp( TABLE, code ) ) {
+			out = TABLE[ code ];
+
+			// Note: we limit ourselves to emojis that are two columns wide--emoji being considered wide characters--hence, minus two. Depending on Unicode support, other emoji may not render as a single glyph.
+			if ( out.length === 2 ) {
+				len -= match.length - 2;
+				return out;
+			}
+		}
+		// If unable to convert an emoji code to a rendered emoji, return the matched substring unchanged:
+		return match;
+	}
+}
+
+
+// EXPORTS //
+
+module.exports = emoji;

lib/node_modules/@stdlib/repl/presentation/lib/parse.js

@@ -24,6 +24,7 @@ var RE_EOL = require( '@stdlib/regexp/eol' );
 var trim = require( '@stdlib/string/trim' );
 var max = require( '@stdlib/math/base/special/max' );
 var style = require( './style_line.js' );
+var emoji = require( './emoji.js' );
 
 
 // VARIABLES //
@@ -109,7 +110,8 @@ function parse( out, str ) {
 					'length': line.length
 				});
 
-				// TODO: apply emojis!
+				// Apply emojis:
+				line = emoji( line );
 
 				// Append the line to the fragment:
 				f.push( line );