There is no chained keyword argument syntax. When you write params(a=b=1) it means params(a=(b=1)) which is equivalent to doing b=1; params(a=1). There is no syntax error because the value of a keyword can be an arbitrary expression and since Julia is an expression-oriented language, everything is an expression, including assignments like b=1. This is the kind of thing a syntax linting tool could warn you about though.
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