There ought to be a repository of common expressions and how they behave in each context
The perl documentation does that, doesn't it? perlop and perlfunc would be the places to look first.
what their default context is
There's no default context. An expression is always in a context. And it's always the caller that determines the context - there's no operator/function that says "you know what, I let my operands run in their default context". (And how could it?)

In reply to Re: Easy Reference for Contexts by JavaFan
in thread Easy Reference for Contexts by cat_baby

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