generalize simple language runners

i.e. if we only run a command and pass the file as the last argument,
then we can use one method for running them all.

go/linguaevalia/linguaevalia.go

@@ -19,11 +19,23 @@ type Language interface {
	Extension() string
}
type LanguageGo struct{}
type LanguagePython struct{}
type LanguageGeneral struct {
	Name    string
	Ext     string
	Command string
	Args    []string
}
func (l LanguageGeneral) RunFile(f *os.File) ([]byte, error) {
	args := append(l.Args, f.Name())
	cmd := exec.Command(l.Command, args...)
	return cmd.CombinedOutput()
}
var Go = LanguageGo{}
var Python = LanguagePython{}
func (l LanguageGeneral) Extension() string { return l.Ext }
var Go = LanguageGeneral{"Go", "go", "go", []string{"run"}}
var Python = LanguageGeneral{"Python", "py", "python", []string{}}
var languageMappings = map[string]Language{
	"go":     Go,
@@ -44,20 +56,6 @@ func writeCode(code string, extension string) (*os.File, error) {
	return f, nil
}
func (l LanguageGo) RunFile(f *os.File) ([]byte, error) {
	cmd := exec.Command("go", "run", f.Name())
	return cmd.CombinedOutput()
}
func (l LanguageGo) Extension() string { return "go" }
func (l LanguagePython) RunFile(f *os.File) ([]byte, error) {
	cmd := exec.Command("python", f.Name())
	return cmd.CombinedOutput()
}
func (l LanguagePython) Extension() string { return "py" }
func Eval(lang Language, code string) ([]byte, error) {
	// write code to temp file
	f, err := writeCode(code, lang.Extension())