Fix example for NamedTuple.from #3911
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| # NamedTuple(foo: String, bar: Int64).from({:foo => "world", :bar => 2}).class # => {foo: String, bar: Int64} | ||
| # ``` | ||
| # num_or_str : Int32 | String | ||
| # num_or_str = 42 |
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This does not creates a union:
num_or_str : Int32 | String
num_or_str = 42
pp typeof(num_or_str) # => Int32Either num_or_str = 42 || "a", num_or_str = 42.as(Int32 | String) or num_or_str = rand >= 0.0 ? 42 : "a" are the usual idioms used for one liners unions.
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Ah thanks - thats interesting since:
str_or_num : String | Int32
str_or_num = 1_i64 => type must be (Int32 | String), not Int64I will use num_or_str = 42.as(Int32 | String) thanks
| # | ||
| # num_or_str = "a string" | ||
| # NamedTuple(name: String, val: Int32).from({"name" => "number", "val" => num_or_str}) # => can't cast String to Int32 |
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To keep consistency, I think the text should be:
# raises TypeCastError (cast from String to Int32 failed)
check PR #3820 and https://github.com/maiha/comment-spec.cr
| # | ||
| # num_or_str = "a string" | ||
| # NamedTuple(name: String, val: Int32).from({"name" => "number", "val" => num_or_str}) # => can't cast String to Int32 |
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To keep consistency, I think the text should be:
# raises TypeCastError (cast from String to Int32 failed)
check PR #3820 and https://github.com/maiha/comment-spec.cr
| # NamedTuple(foo: String, bar: Int64).from({:foo => "world", :bar => 2}).class # => {foo: String, bar: Int64} | ||
| # ``` | ||
| # num_or_str = 42.as(Int32 | String) | ||
| # NamedTuple(name: String, val: Int32).from({"name" => "number", "val" => num_or_str}) # => {name: "number", val: 42} |
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New examples are using Hash instead of NamedTuple for an argument. Also, I'd stick to one-liners in this particular case, otherwise you must to reread previous line to get the value of num_or_str instead of just having it inline along with all expression.
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@Sija the samples were using Hash before. The change is whether the keys are Strings or Symbols. I think is good to show that both will work.
I think is ok to keep num_or_str. The sample is too long, yet simple. The name of the the variable is clear enough I think.
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@bcardiff Are you still waiting for changes on this? |
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@mjago I don't think he is. Thanks for this ❤️ . |
This is a fix to the NamedTuple.from example which should close #3792