Added support for FTL (#2080)

This adds support for FTL (Freemarker language).

components.json

@@ -303,6 +303,11 @@
 			"title": "Fortran",
 			"owner": "Golmote"
 		},
+		"ftl": {
+			"title": "FreeMarker Template Language",
+			"require": "markup-templating",
+			"owner": "RunDevelopment"
+		},
 		"gcode": {
 			"title": "G-code",
 			"owner": "RunDevelopment"

components/prism-ftl.js

@@ -0,0 +1,97 @@
+(function (Prism) {
+
+	// https://freemarker.apache.org/docs/dgui_template_exp.html
+
+	// FTL expression with 4 levels of nesting supported
+	var FTL_EXPR = /(?!<#--)[^()"']|\((?:<expr>)*\)|<#--[\s\S]*?-->|"(?:[^\\"]|\\.)*"|'(?:[^\\']|\\.)*'/.source;
+	for (var i = 0; i < 2; i++) {
+		FTL_EXPR = FTL_EXPR.replace(/<expr>/g, FTL_EXPR);
+	}
+	FTL_EXPR = FTL_EXPR.replace(/<expr>/g, '[^\s\S]');
+
+	var ftl = {
+		'comment': /<#--[\s\S]*?-->/,
+		'string': [
+			{
+				// raw string
+				pattern: /\br("|')(?:(?!\1)[^\\]|\\.)*\1/,
+				greedy: true
+			},
+			{
+				pattern: RegExp(/("|')(?:(?!\1|\$\{)[^\\]|\\.|\$\{(?:<expr>)*?\})*\1/.source.replace(/<expr>/g, FTL_EXPR)),
+				greedy: true,
+				inside: {
+					'interpolation': {
+						pattern: RegExp(/((?:^|[^\\])(?:\\\\)*)\$\{(?:<expr>)*?\}/.source.replace(/<expr>/g, FTL_EXPR)),
+						lookbehind: true,
+						inside: {
+							'interpolation-punctuation': {
+								pattern: /^\$\{|\}$/,
+								alias: 'punctuation'
+							},
+							rest: null
+						}
+					}
+				}
+			}
+		],
+		'keyword': /\b(?:as)\b/,
+		'boolean': /\b(?:true|false)\b/,
+		'builtin-function': {
+			pattern: /((?:^|[^?])\?\s*)\w+/,
+			lookbehind: true,
+			alias: 'function'
+		},
+		'function': /\w+(?=\s*\()/,
+		'number': /\d+(?:\.\d+)?/,
+		'operator': /\.\.[<*!]?|->|--|\+\+|&&|\|\||\?{1,2}|[-+*/%!=<>]=?|\b(?:gt|gte|lt|lte)\b/,
+		'punctuation': /[,;.:()[\]{}]/
+	};
+
+	ftl.string[1].inside.interpolation.inside.rest = ftl;
+
+	Prism.languages.ftl = {
+		'ftl-comment': {
+			// the pattern is shortened to be more efficient
+			pattern: /^<#--[\s\S]*/,
+			alias: 'comment'
+		},
+		'ftl-directive': {
+			pattern: /^<[\s\S]+>$/,
+			inside: {
+				'directive': {
+					pattern: /(^<\/?)[#@][a-z]\w*/i,
+					lookbehind: true,
+					alias: 'keyword'
+				},
+				'punctuation': /^<\/?|\/?>$/,
+				'content': {
+					pattern: /[\s\S]*\S[\s\S]*/,
+					alias: 'ftl',
+					inside: ftl
+				}
+			}
+		},
+		'ftl-interpolation': {
+			pattern: /^\$\{[\s\S]*\}$/,
+			inside: {
+				'punctuation': /^\$\{|\}$/,
+				'content': {
+					pattern: /[\s\S]*\S[\s\S]*/,
+					alias: 'ftl',
+					inside: ftl
+				}
+			}
+		}
+	};
+
+	Prism.hooks.add('before-tokenize', function (env) {
+		var pattern = RegExp(/<#--[\s\S]*?-->|<\/?[#@][a-zA-Z](?:<expr>)*?>|\$\{(?:<expr>)*?\}/.source.replace(/<expr>/g, FTL_EXPR), 'gi');
+		Prism.languages['markup-templating'].buildPlaceholders(env, 'ftl', pattern);
+	});
+
+	Prism.hooks.add('after-tokenize', function (env) {
+		Prism.languages['markup-templating'].tokenizePlaceholders(env, 'ftl');
+	});
+
+}(Prism));

examples/prism-ftl.html

@@ -0,0 +1,21 @@
+<h2>Full example</h2>
+<pre><code>&lt;html>
+&lt;head>
+	&lt;title>Welcome!&lt;/title>
+&lt;/head>
+&lt;body>
+	&lt;h1>
+		Welcome ${user}&lt;#if user == "Big Joe">, our beloved leader&lt;/#if>!
+	&lt;/h1>
+	&lt;p>Our latest product:
+	&lt;a href="${latestProduct.url}">${latestProduct.name}&lt;/a>!
+	&lt;p>See what our happy customers have to say!&lt;/p>
+	&lt;ul>
+	&lt;#list userStories as story>
+		&lt;li>
+			&lt;p>${story.text?esc} - by &lt;span>${story.user.name}&lt;/span>
+		&lt;li>
+	&lt;/#list>
+	&lt;/ul>
+&lt;/body>
+&lt;/html></code></pre>

plugins/autoloader/prism-autoloader.js

@@ -33,6 +33,7 @@
 		"fsharp": "clike",
 		"firestore-security-rules": "clike",
 		"flow": "javascript",
+		"ftl": "markup-templating",
 		"glsl": "clike",
 		"gml": "clike",
 		"go": "clike",

plugins/show-language/prism-show-language.js

@@ -54,6 +54,7 @@
 		"erb": "ERB",
 		"fsharp": "F#",
 		"firestore-security-rules": "Firestore security rules",
+		"ftl": "FreeMarker Template Language",
 		"gcode": "G-code",
 		"gdscript": "GDScript",
 		"gedcom": "GEDCOM",