Update printing for length and size method error #25339
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base/replutil.jl
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| @@ -380,6 +380,10 @@ function showerror(io::IO, ex::MethodError) | |||
| end | |||
| print(io, ")") | |||
| end | |||
| if f_is_function && ( name == :length || name == :size ) | |||
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This should check whether the type that was attempted to be called is an iterator (e.g. using applicable(start, ex.args)) and iteratorsize is HasLength. The error message should then suggest changing the iteratorsize trait or implementing the methods.
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Also needs a test case. Thanks for working on this 👍 |
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Thanks for the comments. For the test case, should we read standard out to ensure that this error is being printed? |
ararslan
added
the
domain:display and printing
base/replutil.jl
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| @@ -380,6 +380,15 @@ function showerror(io::IO, ex::MethodError) | |||
| end | |||
| print(io, ")") | |||
| end | |||
| if f_is_function && applicable(start, ex.args) && !method_exists(f, arg_types) | |||
| if Base.iteratorsize(ex.args) == Base.HasLength() | |||
| print(io, "\nYou may consider implementing an additional", | |||
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I'd just say ... implementing the `length` method. Same below (no need to say "such as", as these are exactly the methods to implement).
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Thanks @nalimilan for the comments. @Keno or others, should embedding-test.jl execute this block and print this error message? If not, what condition would have to be used in this block to prevent the stderr in embedding-test.jl to have this statement? |
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@Keno, I believe this is ready to be reviewed. Let me know if you think other changes should be made. I can also rebase the commits into a single or a couple of commits. |
Change condition to use `applicable` based on comments by @Keno
Based on comments from @nalimilan
Fixes #25232
This commit adds special printing that hints that the user might be missing some of the additional iterator methods such as
lengthandsize.