From 9b019e37aa32263b9853c17ec4e11048ce2df569 Mon Sep 17 00:00:00 2001
From: clyne <clyne@bitgloo.com>
Date: Tue, 29 Dec 2020 19:21:32 -0500
Subject: [PATCH] Clean up readme, add guide

---
 README.md | 38 ++++++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 374051b..21e139f 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,12 @@
 # consteval-huffman
 
-Allows for long strings of text or data to be compressed at compile-time, with an efficient decoder routine for decompression at run-time. The decoder conforms to `std::forward_iterator`, allowing for use in ranged-for or standard algorithms.
+A C++20 utility for compressing string literals at compile-time to save program space. The compressed data can be decompressed at run-time through the use of a decoder that follows `std::forward_iterator`.
 
-Compression is achieved using [Huffman coding](https://en.wikipedia.org/wiki/Huffman_coding), which works by creating short codes (measured in bits) for frequently-occuring characters. This works best on larger pieces of data, or more so data that is limited in its range of values (e.g. written text).
+Compression is achieved using [Huffman coding](https://en.wikipedia.org/wiki/Huffman_coding), which works by creating short codes (measured in bits) for frequently-occuring characters. This works best on larger pieces of data that are limited in their range of values (e.g. written text).
+
+## Requirements
+
+A C++20 compliant compiler. `consteval-huffman` is confirmed to work on gcc 10.1 and later, doesn't work yet on clang.
 
 ## Use cases
 
@@ -12,21 +16,31 @@ A ~3.5kB string of JSON can be compressed down ~2.5kB ([see it on Godbolt](https
 
 **2. Scripts (e.g. Lisp)**
 
-A ~40 line comment-including sample of Lisp can be reduced from 1,662 bytes to 1,244 (418 bytes saved) ([Godbolt](https://godbolt.org/z/Kbenbh)).
+A ~40 line comment-including sample of Lisp can be reduced from 1,662 bytes to 1,251 (412 bytes saved) ([Godbolt](https://godbolt.org/z/Kbenbh)).
+
+**3. Numbers?**
+
+A string of numbers 1 to 100 separated with spaces can be compressed to 64% of its original size ([Godbolt](https://godbolt.org/z/Te17aM)).
 
 ## How to Use
 
 ```cpp
+// 1.
 #include "consteval_huffman.hpp"
 
-// Using the _huffman suffix creates an object with the compressed data.
-// If data is not smaller after compression, the object will keep the data uncompressed.
-constinit auto some_data = "This is my string of data"_huffman;
+// 2.
+auto data = "This is my string of data"_huffman; // "\0\x1 Non-text data works too!"
 
-int main()
-{
-    // Decompress and print out the data
-    for (auto c : some_data)
-        putchar(c);
-}
+// 3.
+for (char c : data)
+    std::cout << c;
 ```
+
+Use `data.begin()` or `data.cbegin()` to get an iterator for the data which decompresses the next byte with every increment.  
+These of course come with `end()` and `cend()`.
+
+Use `data()` to get a pointer to the *compressed* data.
+
+Use `size()` to get the size of the compressed data.
+
+Should compression not decrease the size of the given data, the data will be stored uncompressed. The above functions will still behave as they should.