func if_s(env *environment.Environment, a types.Type) (types.Type, error) {
test, err := types.Car(a)
if err != nil {
return nil, err
}
b, err := Eval(env, test)
if err != nil {
return nil, err
}
var toEval types.Type
if b.(*types.Bool).Value {
toEval, err = types.Cadr(a)
if err != nil {
return nil, err
}
} else {
temp, err := types.Cdr(a)
if err != nil {
return nil, err
}
toEval, err = types.Cadr(temp)
if err != nil {
return nil, err
}
}
return Eval(env, toEval)
}
func define(env *environment.Environment, args types.Type) error {
name, err := types.Car(args)
if err != nil {
return err
}
value, err := types.Cadr(args)
if err != nil {
return err
}
evaldValue, err := Eval(env, value)
if err != nil {
return err
}
environment.Define(env, name.(*types.Symbol), evaldValue)
return nil
}