auto keyword for vars #851
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Sorry that this proposal got largely missed and not promptly reviewed.
I generally like the direction here. I've left one comment, but its pretty minor. I do want to check that the @carbon-language/carbon-leads don't want to see anything else here before moving forward or don't have any concerns.
| Disadvantages: | ||
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| - Type inference becomes the _lack_ of a type, rather than the presence of | ||
| something different. | ||
| - C++'s syntax legacy may have needed `auto` in order to provide type | ||
| inference, where Carbon does not. |
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I think it'd be good to also capture that this creates the potential for ambiguity with expression patterns as well. There are possible ways of addressing that ambiguity (some of which you get into in the background section), but I feel like its still an important consideration in the tradeoff here. @zygoloid might even be able to suggest something here.
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Added a bullet for that, linking the background.
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Mid-air collision between your update and my suggestion. Here's what I'd written up (which looks similar enough to your new bullet):
| Disadvantages: | |
| - Type inference becomes the _lack_ of a type, rather than the presence of | |
| something different. | |
| - C++'s syntax legacy may have needed `auto` in order to provide type | |
| inference, where Carbon does not. | |
| Disadvantages: | |
| - Type inference becomes the _lack_ of a type, rather than the presence of | |
| something different. | |
| - C++'s syntax legacy may have needed `auto` in order to provide type | |
| inference, where Carbon does not. | |
| - Removes syntactic distinction between binding of a new name and reference | |
| to an existing name. Reintroducing this distinction would likely require | |
| additional syntax, such as Swift's nested `let`. |
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Noting here -- replaced mine with @zygoloid's
| Disadvantages: | ||
|
|
||
| - Type inference becomes the _lack_ of a type, rather than the presence of | ||
| something different. | ||
| - C++'s syntax legacy may have needed `auto` in order to provide type | ||
| inference, where Carbon does not. |
There was a problem hiding this comment.
Mid-air collision between your update and my suggestion. Here's what I'd written up (which looks similar enough to your new bullet):
| Disadvantages: | |
| - Type inference becomes the _lack_ of a type, rather than the presence of | |
| something different. | |
| - C++'s syntax legacy may have needed `auto` in order to provide type | |
| inference, where Carbon does not. | |
| Disadvantages: | |
| - Type inference becomes the _lack_ of a type, rather than the presence of | |
| something different. | |
| - C++'s syntax legacy may have needed `auto` in order to provide type | |
| inference, where Carbon does not. | |
| - Removes syntactic distinction between binding of a new name and reference | |
| to an existing name. Reintroducing this distinction would likely require | |
| additional syntax, such as Swift's nested `let`. |
Co-authored-by: Richard Smith <[email protected]>
Co-authored-by: josh11b <[email protected]>
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I was doing this for #851 initially, but I think #438 and #826 hadn't made it in (possibly intentionally due to #851? I don't recall). Co-authored-by: Chandler Carruth <[email protected]> Co-authored-by: Richard Smith <[email protected]>
Allow `var <identifier>: auto = <expression>;` syntax. Co-authored-by: Richard Smith <[email protected]> Co-authored-by: josh11b <[email protected]>
I was doing this for #851 initially, but I think #438 and #826 hadn't made it in (possibly intentionally due to #851? I don't recall). Co-authored-by: Chandler Carruth <[email protected]> Co-authored-by: Richard Smith <[email protected]>
Allow
var <identifier>: auto = <expression>;syntax.