func isPrefixNumDate()

in match/cmp.go [116:152]

• 27 lines of code
• 9 McCabe index (conditional complexity)

func isPrefixNumDate(r *syntax.Regexp) bool {
	if r.Op != syntax.OpConcat || r.Sub[0].Op != syntax.OpBeginText {
		return false
	}

	i := 1
	if isRegularLiteral(r.Sub[i]) {
		i++
	}

	// check starts with digits `\d{n}` or `[0-9]{n}`
	if !isMultiDigits(r.Sub[i]) {
		return false
	}
	i++

	for i < len(r.Sub) {
		// check separator
		if !isRegularLiteral(r.Sub[i]) {
			return false
		}
		i++

		// regex has 'OpLiteral' suffix, without any more digits/patterns following
		if i == len(r.Sub) {
			return true
		}

		// check digits
		if !isMultiDigits(r.Sub[i]) {
			return false
		}
		i++
	}

	return true
}