strings.mml

fn firstOr(v, l) len(l) > 0 ? l[0] : v

export fn (
	join(j, s)              len(s) < 2 ? firstOr("", s) : s[0] + j + join(j, s[1:])
	joins(j, ...s)          join(j, s)
	joinTwo(j, left, right) joins(j, left, right)
	formats(f, ...a)        format(f, a)
	formatOne(f, a)         formats(f, a) // TODO: drop
)

export fn escape(s) {
	if s == "" {
		return ""
	}

	let ~ first s[0]
	switch first {
	case "\b":
		first = "\\b"
	case "\f":
		first = "\\f"
	case "\n":
		first = "\\n"
	case "\r":
		first = "\\r"
	case "\t":
		first = "\\t"
	case "\v":
		first = "\\v"
	case "\"":
		first = "\\\""
	case "\\":
		first = "\\\\"
	}

	return first + escape(s[1:])
}

export fn unescape(s) {
	let (
		~ esc false
		~ r   []
	)

	for i in 0:len(s) {
		let c s[i]
		if esc {
			switch c {
			case "b":
				c = "\b"
			case "f":
				c = "\f"
			case "n":
				c = "\n"
			case "r":
				c = "\r"
			case "t":
				c = "\t"
			case "v":
				c = "\v"
			}

			r = [r..., c]
			esc = false
			continue
		}

		if c == "\\" {
			esc = true
			continue
		}

		r = [r..., c]
	}

	return join("", r)
}