add support for .wat files, add xorscroll.wat example

Cargo.lock

@@ -1543,6 +1543,7 @@ dependencies = [
  "pico-args",
  "uw8-tool",
  "wasmtime",
+ "wat",
 ]
 
 [[package]]

Cargo.toml

@@ -12,4 +12,5 @@ minifb = "0.19"
 notify = "4"
 pico-args = "0.4"
 curlywas = { git = "https://github.com/exoticorn/curlywas.git", rev = "196719b" }
+wat = "1"
 uw8-tool = { path = "uw8-tool" }

examples/wat/xorscroll.wat

@@ -0,0 +1,26 @@
+(module
+  (import "env" "memory" (memory 4))
+  (func (export "upd")
+    (local $i i32) ;; local variables are zero initialized
+
+    (loop $pixels
+      local.get $i ;; pixel index to write to
+
+      (i32.rem_u (local.get $i) (i32.const 320)) ;; x
+      (i32.div_u (i32.load (i32.const 64)) (i32.const 10)) ;; time / 10
+      i32.add
+
+      (i32.div_u (local.get $i) (i32.const 320)) ;; y
+
+      i32.xor ;; (x + time / 10) ^ y
+      (i32.shr_u (i32.const 3)) ;; .. >> 3
+      (i32.and (i32.const 127)) ;; .. & 127
+
+      i32.store8 offset=120 ;; store at pixel index + 120
+
+      (i32.add (local.get $i) (i32.const 1)) ;; i + 1
+      local.tee $i ;; write it back but keep it on the stack
+      (br_if $pixels (i32.lt_s (i32.const 76800))) ;; branch to start of loop if i < 320*240
+    )
+  )
+)

src/main.rs

@@ -97,7 +97,11 @@ fn load_cart(filename: &Path, uw8: &mut MicroW8, config: &Config) -> Result<()>
 
     if cart[0] >= 10 {
         let src = String::from_utf8(cart)?;
-        cart = curlywas::compile_str(&src, filename, curlywas::Options::default())?;
+        cart = if src.chars().find(|c| !c.is_whitespace()) == Some('(') {
+            wat::parse_str(src)?
+        } else {
+            curlywas::compile_str(&src, filename, curlywas::Options::default())?
+        };
     }
 
     if config.pack {