Fun new tupling technique

1 files changed, 69 insertions, 8 deletions

diff --git a/samples/rosetta/variadic_fixed-point_combinator.bruijn b/samples/rosetta/variadic_fixed-point_combinator.bruijn
index cf50875..f5d6ec8 100644
--- a/samples/rosetta/variadic_fixed-point_combinator.bruijn
+++ b/samples/rosetta/variadic_fixed-point_combinator.bruijn
@@ -1,10 +1,13 @@
+:import std/Combinator .
 :import std/Number .
 :import std/List .
 
-y* [[[0 1] <$> 0] ([[1 <! ([[1 2 0]] <$> 0)]] <$> 0)]
+# ---------------
+# explicit Church
+# ---------------
 
-# --- example usage ---
-# mutual recurrence relation of odd?/even?
+# passes all functions explicitly
+explicit-y* [[[0 1] <$> 0] ([[1 <! ([[1 2 0]] <$> 0)]] <$> 0)]
 
 # even x = if x == 0 then true else odd? (x-1)
 g [[[=?0 [[1]] (1 --0)]]]
@@ -12,11 +15,69 @@ g [[[=?0 [[1]] (1 --0)]]]
 # odd x = if x == 0 then false else even? (x-1)
 h [[[=?0 [[0]] (2 --0)]]]
 
-even? ^(y* (g : {}h))
+# merged even/odd
+rec explicit-y* (g : {}h)
 
-odd? _(y* (g : {}h))
+:test (^rec (+5)) ([[0]])
+:test (_rec (+5)) ([[1]])
 
-:test (even? (+5)) ([[0]])
-:test (odd? (+5)) ([[1]])
+# n % 3
+mod3 ^(explicit-y* (zero : (one : {}two)))
+	zero [[[[=?0 (+0) (2 --0)]]]]
+	one [[[[=?0 (+1) (1 --0)]]]]
+	two [[[[=?0 (+2) (3 --0)]]]]
 
-main [[0]]
+:test ((mod3 (+5)) =? (+2)) ([[1]])
+
+# ----------------
+# explicit tupling
+# ----------------
+
+# passes all functions explicitly
+# requires a tuple mapping function first
+tupled-y* [y [[2 (1 0) 0]]]
+
+# merged even odd
+rec tupled-y* map [0 g h]
+	map [&[[[0 (3 2) (3 1)]]]]
+
+# [[1]] / [[0]] are tuple selectors:
+
+:test (rec [[1]] (+5)) ([[0]])
+:test (rec [[0]] (+5)) ([[1]])
+
+# n % 3, [[[2]]] selects first tuple element
+mod3 tupled-y* map [0 zero one two] [[[2]]]
+	map [&[[[[0 (4 3) (4 2) (4 1)]]]]]
+	zero [[[[=?0 (+0) (2 --0)]]]]
+	one [[[[=?0 (+1) (1 --0)]]]]
+	two [[[[=?0 (+2) (3 --0)]]]]
+
+:test ((mod3 (+5)) =? (+2)) ([[1]])
+
+# ---------------
+# implicit Church
+# ---------------
+
+# passes all functions in a single list
+implicit-y* y [[&(1 0) <$> 0]]
+
+# even x = if x == 0 then true else odd? (x-1)
+g [[=?0 [[1]] (_1 --0)]]
+
+# odd x = if x == 0 then false else even? (x-1)
+h [[=?0 [[0]] (^1 --0)]]
+
+# merged even/odd
+rec implicit-y* (g : {}h)
+
+:test (^rec (+5)) ([[0]])
+:test (_rec (+5)) ([[1]])
+
+# n % 3
+mod3 ^(implicit-y* (zero : (one : {}two)))
+	zero [[=?0 (+0) (_1 --0)]]
+	one [[=?0 (+1) (^(~1) --0)]]
+	two [[=?0 (+2) (^1 --0)]]
+
+:test ((mod3 (+5)) =? (+2)) ([[1]])