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| author | Marvin Borner | 2023-10-06 18:51:53 +0200 |
|---|---|---|
| committer | Marvin Borner | 2023-10-06 18:51:53 +0200 |
| commit | e17ea13e7b94986af5d4b60ee6b83a34a0748249 (patch) | |
| tree | a77880dd11e2e5cf437756a28a5e79925377b455 /std/Monad.bruijn | |
| parent | 6a451b6cad18a5b4ba60b6017dbfaa4ab707db8a (diff) | |
Fun with monads
Diffstat (limited to 'std/Monad.bruijn')
| -rw-r--r-- | std/Monad.bruijn | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/std/Monad.bruijn b/std/Monad.bruijn index e015efa..97291eb 100644 --- a/std/Monad.bruijn +++ b/std/Monad.bruijn @@ -2,7 +2,7 @@ # monadic interface for anything based on lists (e.g. IO, strings) # afaik originally proposed by John Tromp and inspired by Haskell -:import std/Pair . +:import std/List . :import std/Combinator . read [0] ⧗ a → (M a) @@ -25,3 +25,20 @@ pure return ⧗ a → (M a) …>>… [[1 >>= [1]]] ⧗ (M a) → (M b) → (M b) :test ((read >> (return 'a')) "hah") ("aah") + +# monadifies a list +lift-m map ⧗ (a → b) → (M a) → (M b) + +# monadifies a list with two monadic arguments +lift-m2 [[[concat ([[4 1 0] <$> 1] <$> 1)]]] ⧗ (a → b → c) → (M a) → (M b) → (M c) + +# evaluates monadic actions +sequence foldr (lift-m2 cons) {}empty ⧗ (List (M a)) → (M (List a)) + +>‣ [sequence ∘∘ 0] + +# performs action n times +replicate-m >replicate ⧗ Number → (M a) → (M (List a)) + +# maps elements to a monadic action +map-m >map ⧗ (a → (M b)) → (List a) → (M (List b)) |