compound assignment

examples/interop/header/app/main.bro

@@ -23,8 +23,8 @@ main :: func() void {
 	_ = native.configured_value(9)
 	_ = native.IMPORTED_SHADOW_OBJECT
 	_ = native.IMPORTED_SHADOW_FUNCTION
-	native.imported_global = native.IMPORTED_MAGIC
-	native.imported_record_global.value = native.IMPORTED_MAGIC
+	native.imported_global += native.IMPORTED_MAGIC
+	native.imported_record_global.value += 2
 	color native.Imported_Color :: native.IMPORTED_COLOR
 	_ = native.imported_check_state(
 		color,

examples/programs/compound_assignment/main.bro

@@ -0,0 +1,45 @@
+# Milestone 6: compound assignment (`+=`, `-=`, `*=`, `/=`) and the binary
+# arithmetic operators `-`, `*`, `/` with multiplicative precedence.
+
+check_float :: func() i32 {
+	x f64 = 10.0
+	x /= 4.0 # 2.5
+	x *= 2.0 # 5.0
+	x -= 1.0 # 4.0
+	x += 0.5 # 4.5
+	if x > 4.0 {
+		return 1
+	}
+	return 0
+}
+
+check_unsigned :: func() i32 {
+	n u32 = 100
+	n /= 7 # 14 (truncating integer division)
+	n -= 4 # 10
+	if n == 10 {
+		return 1
+	}
+	return 0
+}
+
+main :: func() i32 {
+	total i32 = 0
+	total += 10 # 10
+	total -= 3  # 7
+	total *= 4  # 28
+	total /= 2  # 14
+
+	# binary operators honour precedence: 14 + (2 * 3) - 4 == 16
+	total = total + 2 * 3 - 4
+
+	# compound assignment as a while-loop update
+	i i32 = 0
+	while i < 5 : i += 1 {
+		total += 1 # +5 => 21
+	}
+
+	total += check_float()    # +1 => 22
+	total += check_unsigned() # +1 => 23
+	return total
+}