From cc3e680ae7120c3c5e4b521ded64126cfb62bfd5 Mon Sep 17 00:00:00 2001
From: Ekaitz Zarraga <ekaitz@elenq.tech>
Date: Sat, 9 Apr 2022 14:13:06 +0200
Subject: Add prism highlighter support for diff files

---
 themes/elenq/static/js/prism-hl.js | 67 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/themes/elenq/static/js/prism-hl.js b/themes/elenq/static/js/prism-hl.js
index f894d91..ad2a339 100644
--- a/themes/elenq/static/js/prism-hl.js
+++ b/themes/elenq/static/js/prism-hl.js
@@ -1361,3 +1361,70 @@ Prism.languages.yaml = {
 };
 
 Prism.languages.yml = Prism.languages.yaml;
+
+
+(function (Prism) {
+
+	Prism.languages.diff = {
+		'coord': [
+			// Match all kinds of coord lines (prefixed by "+++", "---" or "***").
+			/^(?:\*{3}|-{3}|\+{3}).*$/m,
+			// Match "@@ ... @@" coord lines in unified diff.
+			/^@@.*@@$/m,
+			// Match coord lines in normal diff (starts with a number).
+			/^\d.*$/m
+		]
+
+		// deleted, inserted, unchanged, diff
+	};
+
+	/**
+	 * A map from the name of a block to its line prefix.
+	 *
+	 * @type {Object<string, string>}
+	 */
+	var PREFIXES = {
+		'deleted-sign': '-',
+		'deleted-arrow': '<',
+		'inserted-sign': '+',
+		'inserted-arrow': '>',
+		'unchanged': ' ',
+		'diff': '!',
+	};
+
+	// add a token for each prefix
+	Object.keys(PREFIXES).forEach(function (name) {
+		var prefix = PREFIXES[name];
+
+		var alias = [];
+		if (!/^\w+$/.test(name)) { // "deleted-sign" -> "deleted"
+			alias.push(/\w+/.exec(name)[0]);
+		}
+		if (name === 'diff') {
+			alias.push('bold');
+		}
+
+		Prism.languages.diff[name] = {
+			pattern: RegExp('^(?:[' + prefix + '].*(?:\r\n?|\n|(?![\\s\\S])))+', 'm'),
+			alias: alias,
+			inside: {
+				'line': {
+					pattern: /(.)(?=[\s\S]).*(?:\r\n?|\n)?/,
+					lookbehind: true
+				},
+				'prefix': {
+					pattern: /[\s\S]/,
+					alias: /\w+/.exec(name)[0]
+				}
+			}
+		};
+
+	});
+
+	// make prefixes available to Diff plugin
+	Object.defineProperty(Prism.languages.diff, 'PREFIXES', {
+		value: PREFIXES
+	});
+
+}(Prism));
+
-- 
cgit v1.2.3