update readme

README.md

@@ -1,52 +1,91 @@
-# yo-compiler
+# yo
 
-```c
-package main
+A bytecode compiler and stack-based VM for a statically-typed language.
 
-type Any struct {
-	x,y int;
-	arr [8]int;
-};
+Inspired by Inferno OS's Limbo language and Dis virtual machine.
 
-fn main() int {
-	arr := [8]int{};
-	return nqueen(0, 0, arr[:]);
-};
+## Features
 
-fn fib(n int) int{
-	if n <= 1 {
-		return n;
-	};
-	return fib(n-1) + fib(n-2);
-};
+- Static type system: `int`, `bool`, `struct`, `array`, `slice`, `pointer`
+- Go/Limbo-style syntax: `fn`, `:=`, `for`, `if`
+- Recursion, slicing, struct literals
+- Module system with `package`, `import`, `export`
 
-fn nqueen(r,ans int, arr []int) int{
-	if r == len(arr) {
-		return ans + 1;
-	};
-	for c:=0; c < len(arr); c=c+1{
-		arr[r] = c;
-		if canput(r, arr) {
-			ans = nqueen(r+1, ans, arr);
-		};
-	};
-	return ans;
-};
+## Build
 
-fn canput(r int, arr []int) bool {
-	for i:=0; i < r; i=i+1 {
-		if arr[r] == arr[i] || abs(arr[r] - arr[i]) == abs(r - i) {
-			return false;
-		};
-	};
-	return true;
-};
+	make
 
-fn abs(x int) int {
-	if x < 0 {
-		return x * -1;
-	};
-	return x;
-};
+## Run
+
+Compile a single package:
+
+	./com ./test/fib
+	./vm/run obj
+
+## Test
+
+Run the full test with package imports:
+
+	./com ./test/fib && cp exported obj ./test/fib/
+	./com ./test/nqueen && cp exported obj ./test/nqueen/
+	./com ./test && ./vm/run obj
+	# result 147
+
+## Example
 
 ```
+// test/fib/fib.yo
+package fib
+
+export fn fib(n int) int {
+    if n <= 1 { return n; };
+    return fib(n-1) + fib(n-2);
+};
+```
+
+```
+// test/main.yo
+package main
+
+import "./test/fib"
+import "./test/nqueen"
+
+fn main() int {
+    return fib.fib(10) + nqueen.solve(8);
+};
+```
+
+See [test/](test/) for full examples including N-Queens solver with slices.
+
+## Architecture
+
+Five-stage compilation pipeline:
+
+- [lex.c](lex.c): tokenizer
+- [parse.c](parse.c): recursive descent parser, builds AST
+- [assert.c](assert.c), [type.c](type.c): semantic analysis, type checking
+- [gen.c](gen.c), [com.c](com.c): instruction selection, register allocation
+- [dis.c](dis.c): bytecode serialization
+
+VM execution:
+
+- [vm/vm.c](vm/vm.c): stack-based VM with activation frames
+- [vm/dec.c](vm/dec.c): bytecode decoder
+
+## Files
+
+	lex.c       lexical analyzer
+	parse.c     syntax parser
+	node.c      AST node construction
+	type.c      type system
+	decl.c      declaration and scope management
+	gen.c       instruction generation
+	com.c       expression compiler
+	asm.c       assembly output
+	dis.c       bytecode emitter
+	vm/         virtual machine
+
+## References
+
+- https://github.com/inferno-os/inferno-os/tree/master/dis
+- https://github.com/inferno-os/inferno-os/tree/master/limbo

test.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+./com ./test/fib && cp exported obj ./test/fib/
+./com ./test/nqueen && cp exported obj ./test/nqueen/
+./com ./test && ./vm/run obj