yq/pkg/yqlib/matchKeyString.go

package yqlib

func matchKey(name string, pattern string) (matched bool) {
	if pattern == "" {
		return name == pattern
	}
	if pattern == "*" {
		log.Debug("wild!")
		return true
	}
	return deepMatch(name, pattern)
}

// deepMatch reports whether the name matches the pattern in linear time.
// Source https://research.swtch.com/glob
func deepMatch(name, pattern string) bool {
	px := 0
	nx := 0
	nextPx := 0
	nextNx := 0
	for px < len(pattern) || nx < len(name) {
		if px < len(pattern) {
			c := pattern[px]
			switch c {
			default: // ordinary character
				if nx < len(name) && name[nx] == c {
					px++
					nx++
					continue
				}
			case '?': // single-character wildcard
				if nx < len(name) {
					px++
					nx++
					continue
				}
			case '*': // zero-or-more-character wildcard
				// Try to match at nx.
				// If that doesn't work out,
				// restart at nx+1 next.
				nextPx = px
				nextNx = nx + 1
				px++
				continue
			}
		}
		// Mismatch. Maybe restart.
		if 0 < nextNx && nextNx <= len(name) {
			px = nextPx
			nx = nextNx
			continue
		}
		return false
	}
	// Matched all of pattern to all of name. Success.
	return true
}