규칙 7.9

An expression must be evaluated left to right, as TypeScript and WGSL both evaluate it, and a call that writes (its object, a module variable, a storage binding, an atomic location) inside a larger expression must take effect in that order on every target. The compiler binds each such call to a temporary ahead of its statement, in source order, and binds ahead of the call an operand evaluated before it that reads what it writes; a call TypeScript evaluates conditionally, in an arm of ?: or the right operand of && or ||, keeps its condition as an if. A call that takes a reference (Rule 8.25) is a call that writes each place it is handed, and ref(place) is a place and not a read: a call that writes a variable, in an argument after ref of that variable, runs ahead of the call that takes the reference, which then reads the variable as the call that wrote it left it. A loop condition runs on every iteration, so it may hold such a call only as one side of its comparison.