From 6c832faeaa12861673f5913eb30ad5001e716e4d Mon Sep 17 00:00:00 2001
From: mratsim <mamy.ratsimbazafy_dev@gadz.org>
Date: Thu, 8 Feb 2018 22:02:56 +0100
Subject: [PATCH] Add uint256 support

---
 examples/example_uint.nim | 35 ++++++++++++++++
 src/ttmath.nim            |  3 ++
 src/ttmathuint.nim        | 86 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 examples/example_uint.nim
 create mode 100644 src/ttmathuint.nim

diff --git a/examples/example_uint.nim b/examples/example_uint.nim
new file mode 100644
index 0000000..eb3fdc8
--- /dev/null
+++ b/examples/example_uint.nim
@@ -0,0 +1,35 @@
+import ttmath
+
+var a = 2.u256
+var b = 2.u256
+
+echo a + b
+echo a - b
+echo a * b
+echo a / b
+
+echo a < b
+echo a > b
+echo 3.u256 > b
+echo a < 3.u256
+echo a <= b
+echo a >= b
+a += b
+echo a
+a *= b
+echo a
+a -= b
+echo a
+a /= b
+echo a
+echo a mod b
+echo a div b
+echo a and b
+echo a or b
+echo a xor b
+echo pow(a, 2)
+echo a shl 2
+echo a shr 2
+echo a.getUInt
+echo -a
+echo "02".u256
diff --git a/src/ttmath.nim b/src/ttmath.nim
index 16ca540..1e76fe5 100644
--- a/src/ttmath.nim
+++ b/src/ttmath.nim
@@ -1,3 +1,6 @@
+import ttmathuint
+export ttmathuint
+
 const TTMATH_HEADER = "headers/ttmath.h"
 
 type
diff --git a/src/ttmathuint.nim b/src/ttmathuint.nim
new file mode 100644
index 0000000..0ca62a9
--- /dev/null
+++ b/src/ttmathuint.nim
@@ -0,0 +1,86 @@
+const TTMATH_HEADER = "headers/ttmathuint.h"
+
+type
+  UInt256* {.importc: "ttmath::UInt<4>", header: TTMATH_HEADER.} = object
+    table: array[4, uint64]
+
+  stdString {.importc: "std::string", header: "<string.h>".} = object
+
+proc `+`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# + #)".}
+
+proc `-`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# - #)".}
+
+proc `*`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# * #)".}
+
+proc `/`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# / #)".}
+
+proc `div`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# / #)".}
+
+proc `==`*(a: UInt256, b: UInt256): bool {.importcpp: "(# == #)".}
+
+proc `<`*(a: UInt256, b: UInt256): bool {.importcpp: "(# < #)".}
+
+proc `<=`*(a: UInt256, b: UInt256): bool {.importcpp: "(# <= #)".}
+
+proc `+=`*(a: var UInt256, b: UInt256) {.importcpp: "# += #".}
+
+proc `-=`*(a: var UInt256, b: UInt256) {.importcpp: "# -= #".}
+
+proc `*=`*(a: var UInt256, b: UInt256) {.importcpp: "# *= #".}
+
+proc `/=`*(a: var UInt256, b: UInt256) {.importcpp: "# /= #".}
+
+template `-`*(a: UInt256): UInt256 =
+  0.u256 - a
+
+proc `and`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# & #)".}
+
+proc `or`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# | #)".}
+
+proc `xor`*(a: UInt256, b: UInt256): UInt256 {.importcpp: "(# ^ #)".}
+
+proc u256*(a: uint64): UInt256 {.importcpp: "ttmath::UInt<4>((uint)#)".}
+
+proc u256*(a: cstring): UInt256 {.importcpp: "ttmath::UInt<4>(#)".}
+
+proc u256*(a: string): UInt256 =
+  cstring(a).u256
+
+proc inplacePow(a: var UInt256, b: UInt256) {.importcpp: "(#.Pow(#))".}
+
+proc inplaceDiv(a: var UInt256, b: UInt256, c: var UInt256) {.importcpp: "(#.Div(#, #))".}
+
+proc pow*(a: UInt256, b: uint64): UInt256 =
+  var tmp = a
+  tmp.inplacePow(b.u256)
+  result = tmp
+
+proc `mod`*(a: UInt256, b: UInt256): UInt256 =
+  var tmp = a
+  tmp.inplaceDiv(b, result)
+
+proc ToString(a: UInt256, s: stdString | cstring) {.importcpp: "#.ToString(#)", header: TTMATH_HEADER.}
+
+proc strcpy(c: cstring, s: cstring) {.importc: "strcpy", header: "<cstring>".}
+
+proc c_str(s: stdString): cstring {.importcpp: "#.c_str()", header: "<string.h>".}
+
+#proc toCString*(a: UInt256): cstring =
+
+proc `shl`*(a: UInt256, b: uint64): UInt256 {.importcpp: "(# << #)".}
+
+proc `shr`*(a: UInt256, b: uint64): UInt256 {.importcpp: "(# >> #)".}
+
+proc getUInt*(a: UInt256): uint64 =
+  a.table[0]
+
+proc `$`*(a: UInt256): string =
+  var tmp: stdString
+  # TODO: something smarter
+  {.emit: "tmp = \"                                                                                \";".}
+  var s: cstring
+  {.emit: "s = new char[256];".}
+  a.ToString(tmp)
+  strcpy(s, tmp.c_str())
+  result = $s
+  {.emit: "delete[] s;".}