implement syntax: emoji, custom emoji

README.md

@@ -41,4 +41,9 @@ npm run parse
 ```
 
 ## License
-This software is released under the [MIT License](LICENSE).
+This software is released under the [MIT License](LICENSE) unless otherwise noted.  
+
+This software includes code of therd paty softwares below:  
+- twemoji-parser  
+  Copyright (c) 2018 Twitter, Inc.  
+  MIT Licence: https://github.com/twitter/twemoji-parser/blob/master/LICENSE.md  

src/parser/core-parser.pegjs

@@ -4,6 +4,8 @@
 		mergeText
 	} = require('./parser-utils');
 
+	const emojiRegex = require('./twemoji').default;
+
 	function applyParser(input, startRule) {
 		let parseFunc = peg$parse;
 		return parseFunc(input, startRule ? { startRule } : { });
@@ -14,7 +16,7 @@ rootParser
 	= ts:(block / inline)* { return mergeText(ts); }
 
 plainParser
-	= ts:(text /*/ emoji*/)* { return mergeText(ts); }
+	= ts:(customEmoji / textOrEmoji)* { return mergeText(ts); }
 
 inlineParser
 	= ts:(inline)* { return mergeText(ts); }
@@ -43,12 +45,8 @@ inline
 	// / hashtag
 	// / url
 	// / link
-	// / emoji
-	/ text
-
-text
-	= c:. { return createTree('text', { text: c }); }
-
+	/ customEmoji
+	/ textOrEmoji
 
 // block: title
 
@@ -276,6 +274,27 @@ mathInline
 }
 
 
+// inline: custom emoji
+
+customEmoji
+	= ":" name:$[a-z0-9_+-]+ ":"
+{
+	return createTree('emoji', { name: name });
+}
+
+
+// inline: text or emoji
+
+textOrEmoji
+	= c:((a:[\uD800-\uDBFF] b:[\uDC00-\uDFFF] { return a + b; }) / .)
+{
+	if (emojiRegex.test(c)) {
+		return createTree('emoji', { emoji: c });
+	}
+	return createTree('text', { text: c });
+}
+
+
 // Core rules
 
 CHAR