Add support for Jexl

Jexl is the [Javascript Expression
Language](https://github.com/TomFrost/Jexl).

components.json

@@ -605,6 +605,10 @@
 			"title": "Java stack trace",
 			"owner": "RunDevelopment"
 		},
+		"jexl": {
+			"title": "Jexl",
+			"owner": "czosel"
+		},
 		"jolie": {
 			"title": "Jolie",
 			"require": "clike",

components/prism-jexl.js

@@ -0,0 +1,13 @@
+Prism.languages.jexl = {
+	string: /(["'])(?:\\(?:[\s\S])|(?!\1)[^\\])*\1/,
+	transform: {
+		pattern: /\|\s*[a-zA-Zа-яА-Я_\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF$][a-zA-Zа-яА-Я0-9_\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF$]*/,
+		alias: "function",
+	},
+	function: /[a-zA-Zа-яА-Я_\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF$][a-zA-Zа-яА-Я0-9_\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF$]*\s*(?=\()/,
+	number: /\b(?:(?:\d*\.\d+)|\d+)/,
+	operator: /[<>]=?|[!=]=?|-|\+|&&|\|\||\/\/?|[?:*^%]/,
+	boolean: /\b(?:true|false)\b/,
+	keyword: /\bin\b/,
+	punctuation: /[{}[\](),.]/,
+};

examples/prism-jexl.html

@@ -0,0 +1,8 @@
+<h2>Full example</h2>
+<pre><code>
+[
+  fun(1,2),
+  { obj: "1" }.obj,
+  ctx|transform
+]|join(", ")
+</code></pre>

tests/languages/jexl/boolean_feature.test

@@ -0,0 +1,13 @@
+true
+false
+
+----------------------------------------------------
+
+[
+	["boolean", "true"],
+	["boolean", "false"]
+]
+
+----------------------------------------------------
+
+Checks for booleans.

tests/languages/jexl/function_feature.test

@@ -0,0 +1,96 @@
+foo()
+foo ()
+foo
+()
+foo . bar ()
+foo_bar()
+foo_bar ( )
+f42()
+_()
+$()
+ä()
+Ý()
+foo({ x: 1 })
+foo({ y: fun() })
+foo(bar())
+
+----------------------------------------------------
+
+[
+	["function", "foo"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "foo "],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "foo\r\n"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	"\r\nfoo ",
+	["punctuation", "."],
+	["function", "bar "],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "foo_bar"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "foo_bar "],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "f42"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "_"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "$"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "ä"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "Ý"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	["function", "foo"],
+	["punctuation", "("],
+	["punctuation", "{"],
+	" x",
+	["operator", ":"],
+	["number", "1"],
+	["punctuation", "}"],
+	["punctuation", ")"],
+
+	["function", "foo"],
+	["punctuation", "("],
+	["punctuation", "{"],
+	" y",
+	["operator", ":"],
+	["function", "fun"],
+	["punctuation", "("],
+	["punctuation", ")"],
+	["punctuation", "}"],
+	["punctuation", ")"],
+
+	["function", "foo"],
+	["punctuation", "("],
+	["function", "bar"],
+	["punctuation", "("],
+	["punctuation", ")"],
+	["punctuation", ")"]
+]
+
+----------------------------------------------------
+
+Checks for functions. Also checks for unicode characters in identifiers.

tests/languages/jexl/keyword_feature.test

@@ -0,0 +1,23 @@
+in
+"foo" in ["foo"]
+"f" in "foo"
+
+----------------------------------------------------
+
+[
+	["keyword", "in"],
+
+	["string", "\"foo\""],
+	["keyword", "in"],
+	["punctuation", "["],
+	["string", "\"foo\""],
+	["punctuation", "]"],
+
+	["string", "\"f\""],
+	["keyword", "in"],
+	["string", "\"foo\""]
+]
+
+----------------------------------------------------
+
+Checks for all keywords.

tests/languages/jexl/number_feature.test

@@ -0,0 +1,15 @@
+42
+3.14159
+-5.7
+
+----------------------------------------------------
+
+[
+	["number", "42"],
+	["number", "3.14159"],
+	["operator", "-"], ["number", "5.7"]
+]
+
+----------------------------------------------------
+
+Checks for integers and floats. Negative numbers are handled differently than in Jexl for simplicity: In Jexl, the minus sign in "-1" is parsed as an operator in "1-1" and as part of the number literal in ("-1").

tests/languages/jexl/operator_feature.test

@@ -0,0 +1,33 @@
+-
++
+< <=
+> >=
+= ==
+! !=
+&& ||
+*
+/ //
+^
+? :
+%
+
+----------------------------------------------------
+
+[
+	["operator", "-"],
+	["operator", "+"],
+	["operator", "<"], ["operator", "<="],
+	["operator", ">"], ["operator", ">="],
+	["operator", "="], ["operator", "=="],
+	["operator", "!"], ["operator", "!="],
+	["operator", "&&"], ["operator", "||"],
+	["operator", "*"],
+	["operator", "/"], ["operator", "//"],
+	["operator", "^"],
+	["operator", "?"], ["operator", ":"],
+	["operator", "%"]
+]
+
+----------------------------------------------------
+
+Checks for all operators.

tests/languages/jexl/string_feature.test

@@ -0,0 +1,35 @@
+'a'
+'ä'
+'本'
+'À'
+'\''
+'""'
+'Hello,
+world!'
+
+"\n"
+"\""
+"Hello,
+world!"
+"日本語"
+
+----------------------------------------------------
+
+[
+	["string", "'a'"],
+	["string", "'ä'"],
+	["string", "'本'"],
+	["string", "'À'"],
+	["string", "'\\''"],
+	["string", "'\"\"'"],
+	["string", "'Hello,\r\nworld!'"],
+
+	["string", "\"\\n\""],
+	["string", "\"\\\"\""],
+	["string", "\"Hello,\r\nworld!\""],
+	["string", "\"日本語\""]
+]
+
+----------------------------------------------------
+
+Jexl strings can contain special characters, and even linebreaks.

tests/languages/jexl/transform_feature.test

@@ -0,0 +1,51 @@
+"foo"|bar
+"foo"| bar
+"foo"
+|   
+bar
+
+foo|Ý
+
+foo|bar()
+foo|bar(1,2)
+foo|bar(
+1,2
+)
+
+----------------------------------------------------
+
+[
+	["string", "\"foo\""], ["transform", "|bar"],
+	["string", "\"foo\""], ["transform", "| bar"],
+	["string", "\"foo\""],
+	["transform", "|   \r\nbar"],
+
+	"\r\n\r\nfoo", ["transform", "|Ý"],
+
+	"\r\n\r\nfoo",
+	["transform", "|bar"],
+	["punctuation", "("],
+	["punctuation", ")"],
+
+	"\r\nfoo",
+	["transform", "|bar"],
+	["punctuation", "("],
+	["number", "1"],
+	["punctuation", ","],
+	["number", "2"],
+	["punctuation", ")"],
+
+	"\r\nfoo",
+	["transform", "|bar"],
+	["punctuation", "("],
+
+	["number", "1"],
+	["punctuation", ","],
+	["number", "2"],
+
+	["punctuation", ")"]
+]
+
+----------------------------------------------------
+
+Checks for transforms. Transforms follow the same naming rules as functions.