package ast

import "git.akyoto.dev/cli/q/src/build/token"

// EachInstruction calls the function on each instruction.
func EachInstruction(body token.List, call func(token.List) error) error {
	start := 0
	groupLevel := 0
	blockLevel := 0

	for i, t := range body {
		if start == i && t.Kind == token.NewLine {
			start = i + 1
			continue
		}

		switch t.Kind {
		case token.NewLine:
			if groupLevel > 0 || blockLevel > 0 {
				continue
			}

			err := call(body[start:i])

			if err != nil {
				return err
			}

			start = i + 1

		case token.GroupStart:
			groupLevel++

		case token.GroupEnd:
			groupLevel--

		case token.BlockStart:
			blockLevel++

		case token.BlockEnd:
			blockLevel--
		}
	}

	return nil
}