runtime mutable global state

examples/programs/control_flow/main.bro

@@ -44,11 +44,11 @@ main func() i32 {
 		total = total + 5          # 35
 	}
 
-	# block scoping: inner x shadows outer x, outer is unchanged after the block
+	# block scoping: inner bindings do not escape the block
 	x i32 = 1
 	if x == 1 {
-		x i32 = 100
-		if x == 100 {
+		inner_x i32 = 100
+		if inner_x == 100 {
 			total = total + 5      # 40
 		}
 	}

examples/programs/function_global_unused/main.bro

@@ -1,4 +1,4 @@
-bad int = 1
+bad i32 :: undefined
 
 read_bad func() int {
 	return bad

examples/programs/function_global_used/main.bro

@@ -1,4 +1,4 @@
-bad int = 1
+bad i32 :: undefined
 
 read_bad func() int {
 	return bad

examples/programs/mutable_global/main.bro

@@ -0,0 +1,30 @@
+Point :: struct {
+	x i32
+}
+
+counter int = 0
+ratio float = 1
+span range = 0..2
+point Point = Point { x = 1 }
+values [_]mut i32 = [10, 20]
+
+bump func(value @mut i32) void {
+	value^ += 1
+}
+
+main func() i32 {
+	counter = 10
+	counter += 5
+	bump(&counter)
+	point.x += counter
+	values[1] = point.x
+
+	total i32 = counter + point.x + values[1]
+	for span |i| {
+		total += i
+	}
+	if ratio == 1.0 {
+		total += 1
+	}
+	return total
+}

examples/programs/while_loop/main.bro

@@ -31,12 +31,12 @@ main func() i32 {
 		}
 	}
 
-	# The body-local k shadows only inside the body. The update still targets
+	# Body-local storage stays scoped to the body. The update still targets
 	# the mutable k declared before the loop.
 	k u32 = 0
 	while k < 4 : k = k + 1 {
-		k u32 = 100
-		if k == 100 {
+		body_k u32 = 100
+		if body_k == 100 {
 			total = total + 2
 		}
 	}