diff --git a/lib/minikanren/relations.sx b/lib/minikanren/relations.sx index ca2abf09..1afee3c5 100644 --- a/lib/minikanren/relations.sx +++ b/lib/minikanren/relations.sx @@ -182,6 +182,14 @@ ((nullo l1) (nullo l2)) ((fresh (a d a-prime d-prime) (conso a d l1) (conso a-prime d-prime l2) (rel a a-prime) (mapo rel d d-prime)))))) +(define + iterate-no + (fn + (rel n x result) + (conde + ((== n :z) (== result x)) + ((fresh (n-1 mid) (== n (list :s n-1)) (rel x mid) (iterate-no rel n-1 mid result)))))) + (define everyo (fn diff --git a/lib/minikanren/tests/iterate-no.sx b/lib/minikanren/tests/iterate-no.sx new file mode 100644 index 00000000..56405e52 --- /dev/null +++ b/lib/minikanren/tests/iterate-no.sx @@ -0,0 +1,38 @@ +;; lib/minikanren/tests/iterate-no.sx — iterated relation application. + +(define + mk-nat + (fn (n) (if (= n 0) :z (list :s (mk-nat (- n 1)))))) + +(mk-test + "iterate-no-zero" + (run* + q + (iterate-no + (fn (a b) (== b (list :wrap a))) + (mk-nat 0) + :seed q)) + (list :seed)) + +(mk-test + "iterate-no-three-wraps" + (run* + q + (iterate-no (fn (a b) (== b (list :wrap a))) (mk-nat 3) :x q)) + (list (list :wrap (list :wrap (list :wrap :x))))) + +(mk-test + "iterate-no-succ-three-times" + (run* + q + (iterate-no (fn (a b) (== b (list :s a))) (mk-nat 3) :z q)) + (list (mk-nat 3))) + +(mk-test + "iterate-no-with-list-cons" + (run* + q + (iterate-no (fn (a b) (conso :a a b)) (mk-nat 4) (list) q)) + (list (list :a :a :a :a))) + +(mk-tests-run!) diff --git a/plans/minikanren-on-sx.md b/plans/minikanren-on-sx.md index 5307dc9c..2307e5c2 100644 --- a/plans/minikanren-on-sx.md +++ b/plans/minikanren-on-sx.md @@ -173,6 +173,7 @@ _(none yet)_ _Newest first._ +- **2026-05-08** — **iterate-no**: relational iterated application. Applies a 2-arg relation n times (Peano n) starting from x to produce result. Generalises succ-iteration / list-cons-iteration / etc. 4 new tests, 426/426 cumulative. - **2026-05-08** — **rev-acco / rev-2o**: accumulator-style reversal — faster than appendo-driven reverseo for forward queries because no quadratic appendos. Trade-off: rev-acco is asymmetric (cannot run cleanly backward in run*). 6 new tests, 422/422 cumulative. - **2026-05-08** — **even-i / odd-i (intarith)**: ground-only parity goals via project. Composes with membero for filtered enumeration: -> . 5 new tests, 416/416 cumulative. - **2026-05-08** — **selecto**: classic miniKanren "choose an element + rest". Direct base (l = (x . rest)) plus skip-head recurse. Enumerates all (element, rest) splits in run*; runs forward, backward, mid-pipeline. 6 new tests, 411/411 cumulative.