Disallow shadowing? #86

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scott · 2024-06-17T20:31:27Z

scott commented

2024-06-17 20:31:27 +00:00

No description provided.

scott commented

2024-06-21 02:58:47 +00:00

Is the correct?

Technically, what happens when a function body is a block?

Well, a block is a new scope. So when the function body is a new block, it's a child scope, with the parent scope being the scope for the function body. That means that we would have to special-case the "function body is a block" situation.

I'm disinclined to special-case things.

@matt What do you think? Should the following be allowed?

fn foo (bar) -> {
  let bar = inc (bar) & rebinding of parameter name
}

You wouldn't be able to do

fn foo (bar) -> let bar = bar

But actually, this wouldn't even parse, because function bodies actually must be non-binding expressions.

So the question is, is a block that's a function body different from other kinds of blocks, so people can't re-bind function parameter names?

Is the correct? Technically, what happens when a function body is a block? Well, a block is a new scope. So when the function body is a new block, it's a child scope, with the parent scope being the scope for the function body. That means that we would have to special-case the "function body is a block" situation. I'm disinclined to special-case things. @matt What do you think? Should the following be allowed? ``` fn foo (bar) -> { let bar = inc (bar) & rebinding of parameter name } ``` You wouldn't be able to do ``` fn foo (bar) -> let bar = bar ``` But actually, this wouldn't even parse, because function bodies actually must be non-binding expressions. So the question is, is a block that's a function body different from other kinds of blocks, so people can't re-bind function parameter names?

scott changed title from ~~Validator should not allow re-binding of function parameters~~ to Disallow shadowing?

2024-06-21 14:35:32 +00:00

scott commented

2024-06-21 14:36:27 +00:00

Actually, the conversation leads us to think we should disallow shadowing.

One question is whether we allow shadowing of names bound in Prelude. The first thought is that yes, you can shadow Prelude, but scripts may not shadow bindings they introduce.

Actually, the conversation leads us to think we should disallow shadowing. One question is whether we allow shadowing of names bound in Prelude. The first thought is that yes, you can shadow Prelude, but scripts may not shadow bindings they introduce.

scott added the

accepted

enhancement

labels 2024-07-03 00:18:33 +00:00

scott commented

2024-07-19 20:47:34 +00:00

Validator now disallows shadowing of any name in any context. Next up: develop logic in validator to only check names that are explicitly bound in a script, and not names that are in Prelude.