Add support for the all builtin
#54
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| for ; raised == nil; o, raised = Next(f, iter) { | ||
| if ret, raised := IsTrue(f, o); raised != nil { | ||
| return nil, raised | ||
| } else if !ret { |
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Prefer to avoid else when possible.
if ret, raised := ... {
return ...
}
if !ret {
return ...
}
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I don't know if this is consequential, but he couldn't use that syntax. He would have to declare ret outside of the if:
ret, raised := IsTrue(f, o)
if raised != nil {
return nil, raised
}
if !ret {
return False.ToObject(), nil
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Thanks for pointing that out. The code I wrote isn't correct for that reason. But declaring outside the if is the style I've followed in the source code. It is more verbose (and also pollutes the outer scope's namespace more) but I think the clarity is worth it.
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But declaring outside the if is the style I've followed in the source code.
I will change it to early return, but for the record I lifted that pretty much straight from Contains in core.go 😄
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... declaring outside the if is the style I've tried to follow in the source code... :D
| if !raised.isInstance(StopIterationType) { | ||
| return nil, raised | ||
| } | ||
| f.RestoreExc(nil, nil) |
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It's unfortunate that there's so much boilerplate for iterating over a sequence. seqForEach almost does what you want but doesn't support breaking out of the loop early. We could add support for that by returning an additional bool value from the callback which signals whether to continue. Might be messy though. I'll leave it up to you whether you want to try something like that.
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I will try and see if it gets messy. Thanks for the review!
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Another issue is that seqForEach itself only returns the exception. It would have to be modified to return an *Object as well. Worse than that really -- an object for the false case and one from the true case (and those would probably need to be parameters as well).
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Ugh. Yeah. I think I remember trying to do this at some point and ran into the same thing. Let's leave things as-is and address this down the road with a more general mechanism.
Implement the `all` as defined here: * https://docs.python.org/2/library/functions.html#all
Implement the `any` as defined here:
* https://docs.python.org/2/library/functions.html#any
Note that a new helper function `seqFindFirst` was added that
is used to implement `builtinAll`, `builtinAny`, and `seqContains`.
Implement the `cmp` as defined here: * https://docs.python.org/2/library/functions.html#cmp Implementing this builtin required implementing a fair amount of supporting logic to do 3-way comparisons. The 3-way comparison implementation in CPython is somewhat complex, thus there may be some cases that still need support. This is a good start, though.
Implement the
allas defined here: