Make E0243/E0244 message consistent with E0107

[sinkuu]

E0243/E0233 prints expected {}, found {} on the span note, while E0107 prints it on the first line. This is confusing when both error occur simultaneously.

This PR makes E0243/E0233 print expected {}, found {} on the first line.

Code:

structFoo<'a,'b>{s:&'astr,t:&'bstr,}typeBar<T,U> = Foo<T,U>;

rustc output (before):

error[E0107]: wrong number of lifetime parameters: expected 2, found 0
--> test.rs:6:18
|
6 | type Bar<T, U> = Foo<T, U>;
| ^^^^^^^^^ expected 2 lifetime parameters
error[E0244]: wrong number of type arguments
--> test.rs:6:18
|
6 | type Bar<T, U> = Foo<T, U>;
| ^^^^^^^^^ expected no type arguments, found 2

rustc output (after):

error[E0107]: wrong number of lifetime parameters: expected 2, found 0
--> /tmp/test.rs:6:18
|
6 | type Bar<T, U> = Foo<T, U>;
| ^^^^^^^^^ expected 2 lifetime parameters
error[E0244]: wrong number of type arguments: expected 0, found 2
--> /tmp/test.rs:6:18
|
6 | type Bar<T, U> = Foo<T, U>;
| ^^^^^^^^^ expected no type arguments

[rust-highfive]

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[petrochenkov]

There's one more inconsistency!
E0107 says "parameters" and E0244 says "arguments" while they both should be "arguments".

[sinkuu]

Currently documentations and compiler messages don't tell lifetime arguments/parameters apart (they seem to be called "parameters" everywhere).

[GuillaumeGomez]

cc @jonathandturner

[bors]

☔ The latest upstream changes (presumably #36862) made this pull request unmergeable. Please resolve the merge conflicts.

[GuillaumeGomez]

cc @jonathandturner

[sophiajt]

This looks close, but as @petrochenkov points out both should be arguments since they are calls.

Also this is confusing:

error[E0107]: wrong number of lifetime parameters: expected 2, found 0
--> /tmp/test.rs:6:18
|
6 | type Bar<T, U> = Foo<T, U>;
| ^^^^^^^^^ expected 2 lifetime parameters

You're underlining 2 arguments and saying that's what you expect. How is this an error?

[sinkuu]

T and U are not lifetime arguments but type arguments.

[sophiajt]

@sinkuu do you have an updated example of what it will look like?

[sophiajt]

Ah in that case perhaps it should note the difference. I totally overlooked it

[sinkuu]

I'll try to do that.

[bors]

☔ The latest upstream changes (presumably #37269) made this pull request unmergeable. Please resolve the merge conflicts.

[sinkuu]

Converted "lifetime parameters" to "lifetime arguments".

For noting differences between lifetime args and type args, I'm not sure what the note should say. When types are mixed-up with lifetimes, the compiler will put both E0107 and E0244 anyway.gi

[nikomatsakis]

Hmm I'm of two minds about whether to say "arguments" or "parameters". A quick google search suggests that most people say "generic type parameters" (C#, Java), though there are some who say "arguments" (TypeScript). Definitely searching for "generic type parameters" gives a lot more results (1.6mil) than "generic type arguments (670k, the top few of which are actually saying "parameters"). I definitely agree consistency is better though. =)

[nrc]

+1 for parameters

[brson]

The debate about "arguments" vs "parameters" seems to transcend this PR. Can we just press on as-is?

[nikomatsakis]

@brson agreed, this PR just keeps existing language it seems

[alexcrichton]

In that sense, ping r? @nrc for helping to move forward

[nrc]

@bors: r+

[bors]

📌 Commit 12f0b6f has been approved by nrc

[bors]

⌛ Testing commit 12f0b6f with merge 280362a...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-cargotest, auto-linux-64-cross-freebsd, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-opt-rustbuild, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-opt, auto-mac-64-opt-rustbuild, auto-mac-cross-ios-opt, auto-win-gnu-32-opt, auto-win-gnu-32-opt-rustbuild, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-cargotest, auto-win-msvc-64-opt, auto-win-msvc-64-opt-rustbuild
Approved by: nrc
Pushing 280362a to master...