为JSON Schema优化正则表达式：匹配合规的含重音字符字符串

Hey there! Let's fix your regex problem while checking all your boxes—no more awkward three-group structure, proper首尾 character restrictions, and no consecutive spaces or hyphens. Here's how to do it step by step:

Core Regex Solution #

First, here's the optimized regex that meets all your requirements:

^(?=.{0,100}$)(?:(?!Ð×Þß÷þø)[A-Za-zÀ-ÿŒœ](?:[' -](?!Ð×Þß÷þø)[A-Za-zÀ-ÿŒœ])*)?$

Breakdown of Each Part #

Let's walk through this so you understand exactly how it works:

1. Length Control: (?=.{0,100}$)
   • This positive lookahead ensures the entire string is between 0 and 100 characters long, satisfying your first constraint.
2. Empty String Allowance: The outer (?:...)? makes the entire non-empty pattern optional, so empty strings are valid.
3. Valid Start/End Characters:
   • The pattern starts with (?!Ð×Þß÷þø)[A-Za-zÀ-ÿŒœ]: this matches a valid letter or accented character (including œ, excluding the forbidden Greek/special characters you listed). This immediately blocks spaces, single quotes, or hyphens from appearing at the start.
4. Internal Separators (No Consecutive Ones!):
   • The (?:[' -](?!Ð×Þß÷þø)[A-Za-zÀ-ÿŒœ])* part allows any number of "separator + valid character" pairs.
     • Separators (space, ', -) can only appear between two valid characters, so they'll never end up at the string's tail.
     • Since each separator must be followed by a valid character, consecutive separators (like --, , or - ) are automatically blocked—no extra checks needed!

Test Cases to Validate #

Let's confirm this works for common scenarios:

• Valid: Empty string, "Élodie", "Jean-Luc", "O'Neil", "Marie Claire", a 100-character valid string
• Invalid: " -Test" (starts with separators), "Test-" (ends with hyphen), "Test " (ends with spaces), "Test--Name" (consecutive hyphens), "Ðavid" (contains forbidden character), 101-character string

JSON Schema Integration #

When using this in a JSON Schema, remember to escape backslashes if your tooling requires it. Here's what that looks like:

{
  "type": "string",
  "pattern": "^(?=.{0,100}$)(?:(?!Ð×Þß÷þø)[A-Za-zÀ-ÿŒœ](?:[' -](?!Ð×Þß÷þø)[A-Za-zÀ-ÿŒœ])*)?$"
}

内容的提问来源于stack exchange，提问作者Will59