From 48a659629738399573a451e757652b3c0667528a Mon Sep 17 00:00:00 2001
From: pengzhanbo <volodymyr@foxmail.com>
Date: Wed, 14 Aug 2024 03:54:52 +0800
Subject: [PATCH] perf(plugin-shikiji): improve `highlight whitespace`

---
 .../src/node/utils/whitespace.ts               | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 plugins/plugin-shikiji/src/node/utils/whitespace.ts

diff --git a/plugins/plugin-shikiji/src/node/utils/whitespace.ts b/plugins/plugin-shikiji/src/node/utils/whitespace.ts
new file mode 100644
index 00000000..558d48f2
--- /dev/null
+++ b/plugins/plugin-shikiji/src/node/utils/whitespace.ts
@@ -0,0 +1,18 @@
+export const WHITESPACE_REGEXP = /:whitespace(?:=(all|boundary|trailing)?)?\b/
+export const NO_WHITESPACE_REGEXP = /:no-whitespace\b/
+
+export type WhitespacePosition = 'all' | 'boundary' | 'trailing'
+
+export function resolveWhitespacePosition(info: string, defaultPosition?: boolean | WhitespacePosition): WhitespacePosition | false {
+  if (NO_WHITESPACE_REGEXP.test(info)) {
+    return false
+  }
+
+  defaultPosition = defaultPosition === true ? undefined : defaultPosition
+
+  const match = info.match(WHITESPACE_REGEXP)
+  if (match) {
+    return (match[1] || defaultPosition || 'all') as WhitespacePosition
+  }
+  return defaultPosition ?? false
+}