> - hidden control flow (function calls should look like function calls, an operation should never mask a function call) You can restrict operator definitions

> - hidden control flow (function calls should look like function calls, an operation should never mask a function call) You can restrict operator definitions to expressions containing other operators. Operators are now guaranteed to expose only as much control flow as the underlying operators would already expose. > - global weirdness. If a library changes the language, how does that affect some other code you're pulling in? Where do you effect those changes? I'm not sure what you mean. Behaviour depends on language semantics. You don't specify why operators are uniquely weird on this compared to literally any other function call when language semantics or library behaviour changes.