From aa6c90fa5bbbedaf7bb45cd654c78a00dca4036b Mon Sep 17 00:00:00 2001
From: Oded Shapira <32619328+dondish@users.noreply.github.com>
Date: Fri, 5 Aug 2022 14:45:34 +0300
Subject: [PATCH] includes/type: Added LEB128 type (#40)

* Implement VarInt type

* VarInts are little endian, make result u128

* Rename VarInt to LEB128

* It didn't remove the varint file
---
 includes/type/leb128.pat | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 includes/type/leb128.pat

diff --git a/includes/type/leb128.pat b/includes/type/leb128.pat
new file mode 100644
index 0000000..e9b7603
--- /dev/null
+++ b/includes/type/leb128.pat
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <std/io.pat>
+#include <std/mem.pat>
+
+namespace type {
+	
+	struct LEB128 {
+		u8 array[while($ == addressof(this) || std::mem::read_unsigned($-1, 1) & 0x80 != 0)] [[hidden]];
+	} [[format("type::impl::format_leb128"), transform("type::impl::transform_leb128")]];
+	
+	namespace impl {
+	
+		fn transform_leb128_array(auto array) {
+			u128 res = array[0] & 0x7f;
+			for(u8 i = 1, array[i-1] & 0x80 != 0, i+=1) {
+				res |= u64(array[i] & 0x7f) << 7 * i;
+			}
+			return res;
+		};
+		
+		fn format_leb128(auto leb128) {
+			u128 res = type::impl::transform_leb128_array(leb128.array);
+			return std::format("{} ({:#x})", res, res);
+		};
+	
+		fn transform_leb128(auto leb128) {
+			return type::impl::transform_leb128_array(leb128.array);
+		};
+	}
+	
+}
+