implement bigint

main.ua

@@ -0,0 +1,21 @@
+# bigint
+
+# base -- internal representation of number
+β ← 1e9
+
+# add two little-endian digital bigints
+# ? b1 b2
+Add ← (
+  ˜⊂0⬚0+          # fill-add and expand digits
+  ⍥(+↻¯1⊃(⌊÷)◿β)∞ # carry calc
+  ⍜⇌(⍥↘₁=0⊸⊢)     # trim trailing zeroes
+)
+
+# repeated addition of two little-endian digital bigints
+# ? multiplier multiplicand
+Mult ← ⍥Add⌝⊥β ⊙(⊥β0)
+
+┌─╴test
+  ⍤⤙≍ ⊙+◡(⌝⊥β Add ∩(⊥β)) 10000000000000 10000000000000
+  ⍤⤙≍ ⊙×◡(⌝⊥β Mult ∩(⊥β)) 3 7
+└─╴