nix-amer/internal/instruction/reader.go

package instruction

import (
	"strings"
)

// Parse from a raw line
func Parse(raw string) (T, error) {

	// 1. format (trim + split first space)
	split := strings.SplitN(raw, " ", 2)
	if len(split) < 2 { // at least 1 command + arguments
		return nil, ErrInvalidSyntax
	}

	split[0] = strings.Trim(split[0], " \t")

	// 2. fail if invalid base syntax 'cmd args...'
	split[1] = strings.Trim(split[1], " \t")

	// 3. Extract instruction type
	switch split[0] {
	case "install":
		i := &install{}
		err := i.Build(split[1])
		return i, err
	case "delete":
		i := &delete{}
		err := i.Build(split[1])
		return i, err
	case "service":
		i := &service{}
		err := i.Build(split[1])
		return i, err
	case "run":
		i := &run{}
		err := i.Build(split[1])
		return i, err
	case "set":
		i := &set{}
		err := i.Build(split[1])
		return i, err
	case "alias":
		i := &alias{}
		err := i.Build(split[1])
		return i, err
	default:
		return nil, ErrUnknownInstruction
	}

	// return nil, nil
}