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+Which type should numeric operations use?
+
+Currently, it works like this:
+
+    byte a = 250
+    byte b = 10
+    ...
+    byte x = (a + b) - 20   # this overflows, because a+b is computed as a byte
+
+And this is actually inefficient, because the operation would most likely be
+performed using 32 or even 64 bit registers. The exception is when the
+temporary variable for (a+b) is spilled to stack.
+
+Comparison to other languages
+-----------------------------
+
+C (from reading the ANSI C spec):
+    - performs operations as int or a larger type
+    - promotes to the largest operand (appears to not care about the result type)
+    - unsigned wins when there are operands with mixed signedness
+
+Rust (from reading random blogs):
+    - all integer literals need to have a suffix, e.g. u8
+      (except for the default, which I think is int?)
+    - all casts, even narrowing ones, have to be explicit
+
+FreePascal (don't remember this exactly):
+    - Promotes to Int64 in mixed-sign comparisons