dify

dify/web/app/components/datasets/create/step-two/unescape.ts

@@ -0,0 +1,54 @@
+// https://github.com/iamakulov/unescape-js/blob/master/src/index.js
+
+/**
+ * \\ - matches the backslash which indicates the beginning of an escape sequence
+ * (
+ *   u\{([0-9A-Fa-f]+)\} - first alternative; matches the variable-length hexadecimal escape sequence (\u{ABCD0})
+ * |
+ *   u([0-9A-Fa-f]{4}) - second alternative; matches the 4-digit hexadecimal escape sequence (\uABCD)
+ * |
+ *   x([0-9A-Fa-f]{2}) - third alternative; matches the 2-digit hexadecimal escape sequence (\xA5)
+ * |
+ *   ([1-7][0-7]{0,2}|[0-7]{2,3}) - fourth alternative; matches the up-to-3-digit octal escape sequence (\5 or \512)
+ * |
+ *   (['"tbrnfv0\\]) - fifth alternative; matches the special escape characters (\t, \n and so on)
+ * |
+ *   \U([0-9A-Fa-f]+) - sixth alternative; matches the 8-digit hexadecimal escape sequence used by python (\U0001F3B5)
+ * )
+ */
+const jsEscapeRegex = /\\(u\{([0-9A-Fa-f]+)\}|u([0-9A-Fa-f]{4})|x([0-9A-Fa-f]{2})|([1-7][0-7]{0,2}|[0-7]{2,3})|(['"tbrnfv0\\]))|\\U([0-9A-Fa-f]{8})/g
+
+const usualEscapeSequences: Record<string, string> = {
+  '0': '\0',
+  'b': '\b',
+  'f': '\f',
+  'n': '\n',
+  'r': '\r',
+  't': '\t',
+  'v': '\v',
+  '\'': '\'',
+  '"': '"',
+  '\\': '\\',
+}
+
+const fromHex = (str: string) => String.fromCodePoint(Number.parseInt(str, 16))
+const fromOct = (str: string) => String.fromCodePoint(Number.parseInt(str, 8))
+
+const unescape = (str: string) => {
+  return str.replace(jsEscapeRegex, (_, __, varHex, longHex, shortHex, octal, specialCharacter, python) => {
+    if (varHex !== undefined)
+      return fromHex(varHex)
+    else if (longHex !== undefined)
+      return fromHex(longHex)
+    else if (shortHex !== undefined)
+      return fromHex(shortHex)
+    else if (octal !== undefined)
+      return fromOct(octal)
+    else if (python !== undefined)
+      return fromHex(python)
+    else
+      return usualEscapeSequences[specialCharacter]
+  })
+}
+
+export default unescape