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README.md

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+# nibbles
+
+A toy C library that converts numbers to and from [BCD](https://en.wikipedia.org/wiki/Binary-coded_decimal).
+I suggest you don't use it.
+
+## Installation
+
+Don't. The makefile only includes a test target, because I want to test my code.
+
+## Usage
+
+The library knows how to convert `uint<n>_t` types into BCD. It also knows
+how to convert them back into `uint64_t`—only that because any other
+representation might lead to a loss of information. It can also convert from
+BCD to strings. The functions are:
+
+```c
+bcd bcd_zeros(); // creates a BCD of value 0
+
+bcd bcd_from_8(uint8_t); // creates a BCD from a byte
+bcd bcd_from_16(uint16_t); // creates a BCD from 2 bytes
+bcd bcd_from_32(uint32_t); // and so on
+bcd bcd_from_64(uint64_t); // ..
+
+uint8_t bcd_digits(bcd); // gets the number of digits in the BCD
+uint64_t bcd_to_64(bcd); // converts a BCD to a 8 bytes (64 bit) number
+char* bcd_to_string(bcd); // converts a BCD to a string (memory is now yours)
+```
+
+That's it!
+
+<hr/>
+
+Have fun!