More std functions

3 files changed, 43 insertions, 11 deletions

diff --git a/std/Float.bruijn b/std/Float.bruijn
new file mode 100644
index 0000000..d3fce4e
--- /dev/null
+++ b/std/Float.bruijn
@@ -0,0 +1,16 @@
+# MIT License, Copyright (c) 2022 Marvin Borner
+# Arbitrary-precision floating-point arithmetic implementation using
+#   (+3.14) = pair (+3) (+14)
+
+:import std/Combinator .
+:import std/Number .
+:import std/List .
+:import std/Pair P
+
+# generates a float from a normal balanced ternary number
+float! \(P.:) (+0)
+
+# adds two floating numbers
+# TODO: Carry support
+# - needed: mod, div (?) -> ternary carry != decimal carry
+add P.zip-with (+)
diff --git a/std/Math.bruijn b/std/Math.bruijn
index 31dd572..d63fb2f 100644
--- a/std/Math.bruijn
+++ b/std/Math.bruijn
@@ -58,9 +58,9 @@ gcd z [[[(1 =? 0) case-eq ((1 >? 0) case-gre case-les)]]] ⧗ Number → Number
 	case-gre 2 (1 - 0) 0
 	case-les 2 1 (0 - 1)
 
-:test ((gcd (+2) (+4)) =? ((+2))) (true)
-:test ((gcd (+10) (+5)) =? ((+5))) (true)
-:test ((gcd (+3) (+8)) =? ((+1))) (true)
+:test ((gcd (+2) (+4)) =? (+2)) (true)
+:test ((gcd (+10) (+5)) =? (+5)) (true)
+:test ((gcd (+3) (+8)) =? (+1)) (true)
 
 # power function
 pow […!!… (iterate (…⋅… 0) (+1))] ⧗ Number → Number → Number
diff --git a/std/Number/Unary.bruijn b/std/Number/Unary.bruijn
index 244eefb..edc9dcd 100644
--- a/std/Number/Unary.bruijn
+++ b/std/Number/Unary.bruijn
@@ -1,14 +1,13 @@
 # MIT License, Copyright (c) 2022 Marvin Borner
+# with help from Justine Tunney
 # classic Church style numerals
 
 :import std/Logic .
 :import std/Combinator .
 :import std/Pair .
 
-zero [[0]]
-
 # returns true if a unary number is zero
-zero? [0 [zero] true] ⧗ Unary → Boolean
+zero? [0 [(+0u)] true] ⧗ Unary → Boolean
 
 =?‣ zero?
 
@@ -114,8 +113,7 @@ mul …∘… ⧗ Unary → Unary → Unary
 :test ((+2u) ⋅ (+3u)) ((+6u))
 
 # divs two unary numbers
-div [z div* ++0] ⧗ Unary → Unary → Unary
-	div* [[[[[[=?0 ((+0u) 2 1) (2 (5 0 3 2 1))] (3 - 2)]]]]]
+div [[[[3 [[0 1]] [1] (3 [3 [[0 1]] [3 (0 1)] [0]] 0)]]]] ⧗ Unary → Unary → Unary
 
 …/… div
 
@@ -124,16 +122,23 @@ div [z div* ++0] ⧗ Unary → Unary → Unary
 :test ((+2u) / (+2u)) ((+1u))
 :test ((+2u) / (+3u)) ((+0u))
 
+# slower div
+div* [z rec ++0] ⧗ Unary → Unary → Unary
+	rec [[[[[[=?0 ((+0u) 2 1) (2 (5 0 3 2 1))] (3 - 2)]]]]]
+
 # returns remainder of integer division
-mod [[1 [0 [[(0 ⋀? (3 ≤? 1)) case-rec case-end]]] (1 : true) [[1]]]] ⧗ Unary → Unary → Unary
-	case-rec (1 - 3) : true
-	case-end 1 : false
+mod [[[[3 [0 [[1]]] (3 [3 [[[0 (2 (5 1)) 1]]] [1] 1] [1]) [[0]]]]]] ⧗ Unary → Unary → Unary
 
 …%… mod
 
 :test ((+10u) % (+3u)) ((+1u))
 :test ((+3u) % (+5u)) ((+3u))
 
+# slower mod
+mod* [[1 [0 [[(0 ⋀? (3 ≤? 1)) case-rec case-end]]] (1 : true) [[1]]]] ⧗ Unary → Unary → Unary
+	case-rec (1 - 3) : true
+	case-end 1 : false
+
 # exponentiates two unary number
 # doesn't give correct results for x^0
 pow* [[1 0]] ⧗ Unary → Unary → Unary
@@ -145,3 +150,14 @@ pow [[0 [[3 (1 0)]] [[1 0]]]] ⧗ Unary → Unary → Unary
 
 :test ((+2u) ^ (+3u)) ((+8u))
 :test ((+3u) ^ (+2u)) ((+9u))
+
+# fibonacci sequence
+# index +1 vs std/Math fib
+fib [0 [[[2 0 [2 (1 0)]]]] [[1]] [0]] ⧗ Unary → Unary
+
+:test (fib (+6u)) ((+8u))
+
+# factorial function
+fac [[1 [[0 (1 [[2 1 (1 0)]])]] [1] [0]]] ⧗ Unary → Unary
+
+:test (fac (+3u)) ((+6u))