patterns: Added protobuf pattern

patterns/protobuf.hexpat

@@ -0,0 +1,66 @@
+#include <std/mem.pat>
+
+#include <type/leb128.pat>
+
+struct ZigZag32 {
+	u32 value;
+} [[sealed, format("format_zigzag32")]];
+
+fn format_zigzag32(ZigZag32 zigzag) {
+	return s32((zigzag.value << 1) ^ (zigzag.value >> 31));
+};
+
+struct ZigZag64 {
+	u64 value;
+} [[sealed, format("format_zigzag64")]];
+
+fn format_zigzag64(ZigZag64 zigzag) {
+	return s64((zigzag.value << 1) ^ (zigzag.value >> 63));
+};
+
+enum WireType : u8 {
+	Varint 			= 0,
+	_64Bit 			= 1,
+	LengthDelimited = 2,
+	StartGroup 		= 3,
+	EndGroup 		= 4,
+	_32Bit 			= 5
+};
+
+bitfield Key {
+	field_number : 5;
+	wire_type    : 3;
+} [[left_to_right]];
+
+union _64Bit {
+	u64 fixed64;
+	ZigZag64 sfixed64;
+	double dbl;
+};
+
+union _32Bit {
+	u32 fixed32;
+	ZigZag32 sfixed32;
+	float flt;
+};
+
+struct LengthDelimited {
+	type::LEB128 length;
+	char data[length];
+};
+
+
+struct Entry {
+	Key key;
+	
+	if (key.wire_type == WireType::Varint)
+		type::LEB128 value;
+	else if (key.wire_type == WireType::_64Bit)
+		_64Bit value;
+	else if (key.wire_type == WireType::LengthDelimited)
+		LengthDelimited value;
+	else if (key.wire_type == WireType::_32Bit)
+		_32Bit value;
+};
+
+Entry entries[while(!std::mem::eof())] @ 0x00;