textedit/sequence.go

package textedit

func sequenceEdit(e []Editor) func(rune, []any) ([]rune, []any) {
	return func(r rune, s []any) ([]rune, []any) {
		var sr []any
		rr := []rune{r}
		for i, ei := range e {
			si := s[i]
			rin := rr
			rr = nil
			for _, ri := range rin {
				var rout []rune
				rout, si = ei.Edit(ri, si)
				rr = append(rr, rout...)
			}

			sr = append(sr, si)
		}

		return rr, sr
	}
}

func sequenceRelease(e []Editor) func([]any) []rune {
	return func(s []any) []rune {
		var rr []rune
		for i, ei := range e {
			r := ei.ReleaseState(s[i])
			for _, ri := range r {
				rri, ssi := sequenceEdit(e[i+1:])(ri, s[i+1:])
				rr = append(rr, rri...)
				s = append(s[:i+1], ssi...)
			}
		}

		return rr
	}
}

func sequence(e ...Editor) Editor {
	init := make([]any, len(e))
	for i, ei := range e {
		if initializer, ok := ei.(interface{ initialize() any }); ok {
			init[i] = initializer.initialize()
		}
	}

	return FuncInit(
		sequenceEdit(e),
		sequenceRelease(e),
		init,
	)
}