  We reflect on programming with complicated effects, recalling an
undeservingly forgotten alternative to monadic programming and checking to see
how well it can actually work in modern functional languages. We adopt and
argue the position of factoring an effectful program into a first-order
effectful DSL with a rich, higher-order 'macro' system. Not all programs can be
thus factored. Although the approach is not general-purpose, it does admit
interesting programs. The effectful DSL is likewise rather problem-specific and
lacks general-purpose monadic composition, or even functions. On the upside, it
expresses the problem elegantly, is simple to implement and reason about, and
lends itself to non-standard interpretations such as code generation
(compilation) and abstract interpretation. A specialized DSL is liable to be
frequently extended; the experience with the tagless-final style of DSL
embedding shown that the DSL evolution can be made painless, with the maximum
code reuse. We illustrate the argument on a simple but representative example
of a rather complicated effect -- non-determinism, including committed choice.
Unexpectedly, it turns out we can write interesting non-deterministic programs
in an ML-like language just as naturally and elegantly as in the
functional-logic language Curry -- and not only run them but also statically
analyze, optimize and compile. The richness of the Meta Language does, in
reality, compensate for the simplicity of the effectful DSL. The key idea goes
back to the origins of ML as the Meta Language for the Edinburgh LCF theorem
prover. Instead of using ML to build theorems, we now build (DSL) programs.
