Function substringIndFunc

func.go:505–542

substringIndFunc is XPath functions substring-before/substring-after function returns a part of a given string.

(arg1, arg2 query, after bool)

// substringIndFunc is XPath functions substring-before/substring-after function returns a part of a given string.
func substringIndFunc(arg1, arg2 query, after bool) func(query, iterator) interface{} {
	return func(_ query, t iterator) interface{} {
		var str string
		switch v := functionArgs(arg1).Evaluate(t).(type) {
		case string:
			str = v
		case query:
			node := v.Select(t)
			if node == nil {
				return ""
			}
			str = node.Value()
		}
		var word string
		switch v := functionArgs(arg2).Evaluate(t).(type) {
		case string:
			word = v
		case query:
			node := v.Select(t)
			if node == nil {
				return ""
			}
			word = node.Value()
		}
		if word == "" {
			return ""
		}

		i := strings.Index(str, word)
		if i < 0 {
			return ""
		}
		if after {
			return str[i+len(word):]
		}
		return str[:i]
	}
}

// stringLengthFunc is XPATH string-length( [string] ) function that returns a number
// equal to the number of characters in a given string.