--- /dev/null
+'use strict'
+
+module.exports = alphabetical
+
+// Check if the given character code, or the character code at the first
+// character, is alphabetical.
+function alphabetical(character) {
+ var code = typeof character === 'string' ? character.charCodeAt(0) : character
+
+ return (
+ (code >= 97 && code <= 122) /* a-z */ ||
+ (code >= 65 && code <= 90) /* A-Z */
+ )
+}