Update README.md

README.md

@@ -2,12 +2,21 @@
 
 This is an attempt to create a Lua virtual machine capable of true multithreading. Once the nctref compiler matures enough, I intend to plug it into Impotent as a JIT.
 
+Completed features:
+
+1. Per-thread heap /w special heap for exited threads called the "dead heap"
+2. Naive mark & sweep GC
+3. Thread-safe user interface (but barely tested)
+
 Impotent is still work-in-progress:
 
 1. Integers are 32-bit only
 2. No error handling, meaning any mistake will either crash the VM or make it silently fail
-3. No standard library other than `print`
+3. The only standard library is `print` and it doesn't work correctly
 4. Tables cannot be resized
-5. Most operators are missing
+5. Most operators are still missing
-6. Integers and floats are always separate table keys (unlike real Lua where e.g. `5` and `5.0` are considered identical)
+6. The user API is completely different from that of PoC Lua
-7. The GC isn't real and everything leaks
+
+Impotent requires C11 and an architecture with 8-byte atomic operations, but otherwise it is completely cross-platform.
+
+Performance-wise, it's surprisingly competitive with PoC Lua, considering how quickly it was made up to the point of writing this README (~2 weeks). By far the worst bottleneck is the GC, since it requires all threads and their heaps to synchronize.