初次提交

src/index.ts

@@ -0,0 +1,36 @@
+import { escapeTable, unescapeTable } from "./table"
+
+/**
+ * escape string to HTML special entities
+ * @param str string
+ * @returns 
+ */
+export function escape(str: string) {
+	const buffer: Array<string> = []
+	let prev = 0
+	for (let i = 0; i < str.length; ++i) {
+		const cc = str.charCodeAt(i)
+		const name = escapeTable[cc]
+		if (name) {
+			buffer.push(str.substring(prev, i))
+			buffer.push(`&${name};`)
+			prev = i + 1
+		}
+	}
+	return buffer.join('')
+}
+
+/**
+ * unescape HTML special entities to normal string
+ * @param str string
+ * @returns 
+ */
+export function unescape(str: string) {
+	return str.replace(/&(\w+);/g, (match, name, index) => {
+		const code = unescapeTable[name]
+		if (!code) return match
+		return String.fromCharCode(code)
+	})
+}
+
+export default { escape, unescape }