Function isUrlChar

src/ink/selection.ts:260–264

(c: string)

// check below is exact (no wide-char/grapheme drift).
const URL_BOUNDARY = new Set([...'<>"\'` '])
function isUrlChar(c: string): boolean {
  if (c.length !== 1) return false
  const code = c.charCodeAt(0)
  return code >= 0x21 && code <= 0x7e && !URL_BOUNDARY.has(c)
}

/**
 * Scan the screen buffer for a plain-text URL at (col, row). Mirrors the