Fixes#45652.
Change-Id: I5e1434480c12815369a6ce204f3729eb63139125
Reviewed-on: https://go-review.googlesource.com/c/go/+/405757
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Taking into account the discussion and relevant feedback on a
change proposed in 2013 (see e-mail thread mentioned in issue).
Fixes#48864.
Change-Id: I811d518b7cbdf6b815695174f1da3d4251f491c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/405756
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Fixes#52628.
Change-Id: If4261abc25868d62f7689253d40f872692c23a4d
Reviewed-on: https://go-review.googlesource.com/c/go/+/405755
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Change scope rules per the accepted proposal #52038.
Match prose for type parameters of type declarations.
Fixing the implementation is tracked by #51503.
Fixes#52038.
For #51503.
Change-Id: Iebd88a82c896b7b2e8520cd514ef6a2cc903e807
Reviewed-on: https://go-review.googlesource.com/c/go/+/405754
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Change-Id: I0ab34f2f931e0e712218e4eb086f4535cc17775c
Reviewed-on: https://go-review.googlesource.com/c/go/+/405614
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Be explicit that we always mean non-interface types when we
talk about sets of types.
Also, clarify that the quantification "all non-interface types"
means all such types in all possible programs, not just the
current program.
Per suggestion from Philip Wadler.
Change-Id: Ibc7b5823164e547bfcee85d4e523e58c7c27ac8a
Reviewed-on: https://go-review.googlesource.com/c/go/+/398655
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Even though the change in the behavior of 'runtime.GOROOT' was
not actually due to a change in the runtime package proper, I
suspect that users who notice it will look for the release note
in that section, not the 'cmd/go' section.
Fixes#51461.
Change-Id: I271752968d4152a7fdf3e170537e3072bf87ce86
Reviewed-on: https://go-review.googlesource.com/c/go/+/400814
Reviewed-by: Ian Lance Taylor <iant@google.com>
They were swapped.
Fixes#52205
Change-Id: Iea2626aa2204f3bc96d08c571a1aa669436a32ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/398895
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This reverts a behavior change introduced in Go 1.18 (commit 9f69a443;
CL 340049). In Go 1.17 and earlier, draw.Draw(etc, draw.Src) with
image.NRGBA dst and src images would pass through a (heap allocated)
color.Color interface value holding a color.NRGBA concrete value.
Threading that color.NRGBA value all the way through preserves
non-premultiplied alpha transparency information (distinguishing e.g.
transparent blue from transparent red).
CL 340049 optimized out that heap allocation (per pixel), calling new
SetRGBA64At and RGBA64At methods instead. However, these methods (like
the existing image/color Color.RGBA method) work in premultiplied alpha,
so any distinction between transparent colors is lost.
This commit re-introduces the preservation of distinct transparencies,
when dst and src are both *image.NRGBA (or both *image.NRGBA64) and the
op is draw.Src.
Fixes#51893
Change-Id: Id9c64bfeeaecc458586f169f50b99d6c8aa52a7f
Reviewed-on: https://go-review.googlesource.com/c/go/+/396795
Trust: Nigel Tao <nigeltao@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
In the Type identity section, the example provides various types as givens.
The example refers to the type *T5, but it is not provided in the givens.
I am assuming this was a typo, and was meant to refer to *A1 or *B1.
*B1 seems to be in alignment with the rest of the provided examples.
Change-Id: I554319ee8bca185c3643559321417e8b2a544ba0
GitHub-Last-Rev: e80560d32a
GitHub-Pull-Request: golang/go#52143
Reviewed-on: https://go-review.googlesource.com/c/go/+/398075
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Ian Lance Taylor <iant@golang.org>
Change timeouts to be Is(context.DeadlineExceeded) and cancelation to
be Is(context.Canceled).
Fixes#51428
Change-Id: Ic580bd9da0f338e993fb79138875a78d99cc1a1d
Reviewed-on: https://go-review.googlesource.com/c/go/+/396877
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Octal values over 255, like \400 or \777, are illegal. It wasn't clear if the expected behavior was a compile error, encoding the value as two characters, or if the value would be capped at 255.
This example explicitly shows that octal values over 255 are illegal.
Change-Id: I45d94680107029c5f083e5d434e6270cc5b258c1
GitHub-Last-Rev: f6bef0379f
GitHub-Pull-Request: golang/go#52111
Reviewed-on: https://go-review.googlesource.com/c/go/+/397555
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
\u007f is not wrong but it's weird to use \u when we could use the
shorter \x.
Fixes#52062
Change-Id: Ica4bdc2463128051876f44e15297ed1e9edf1de8
Reviewed-on: https://go-review.googlesource.com/c/go/+/397255
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Be clear that the type of a term (not the term itself, which may
be of the form ~P) cannot be a type parameter.
For #50420.
Change-Id: I388d57be0618393d7ebe2c74ec04c1ebe3f33f7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/396915
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
For #51572
Change-Id: Ib27be79379c8b3f72e29365b58067d7ee1919e52
Reviewed-on: https://go-review.googlesource.com/c/go/+/396295
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
- Allow for a type parameter as length/capacity to make.
- Be slightly more precise in prose for append.
- Add a couple of links.
Change-Id: Ib97e528bab1ab55d271beeeb53d9bb7a07047b9b
Reviewed-on: https://go-review.googlesource.com/c/go/+/391754
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
- Remove "Draft" disclaimer. We're not done but the spec
is in usable shape with respect to generics features.
- Remove section on "Earlier version" and fold information
into the "Intro" section.
- Remove caveat for shifts: the rules for arithmetic operators
on type parameters apply for them as well.
- Simply state that we don't support arguments of type parameter
type for the built-ins real, imag, and complex.
Fixes#51182.
Change-Id: I6df1427de685cfe7055b64e91753aa7ebff70565
Reviewed-on: https://go-review.googlesource.com/c/go/+/391695
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
- Change section title from "Type parameters lists" to
"Type parameter declarations" as the enclosing section
is about declarations.
- Correct section on parsing ambiguity in type parameter
lists.
- Rephrase paragraphs on type parameters for method receivers
and adjust examples.
- Remove duplicate prose in section on function argument type
inference.
- Clarified "after substitution" column in Instantiations section.
Change-Id: Id76be9804ad96a3f1221e5c4942552dde015dfcb
Reviewed-on: https://go-review.googlesource.com/c/go/+/390994
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Specific types were introduced to explain rules for operands of
type parameter type. Specific types are really an implementation
mechanism to represent (possibly infinite) type sets in the machine;
they are not needed in the specification.
A specific type is either standing for a single named or unnamed
type, or it is the underlying (unnamed) type of an infinite set of
types. Each rule that applies to a type T of the set of specific
types must also apply to all types T' in the type set for which T
is a representative of. Thus, in the spec we can simply refer to
the type set directly, infinite or not.
Rather then excluding operands with empty type sets in each instance,
leave unspecified what happens when such an operand is used. Instead
give an implementation some leeway with an implementation restriction.
(The implementation restriction also needs to be formulated for types,
such as in conversions, which technically are not "operands". Left for
another CL.)
Minor: Remove the two uses of the word "concrete" to refer to non-
interface types; instead just say "non-interface type" for clarity.
Change-Id: I67ac89a640c995369c9d421a03820a0c0435835a
Reviewed-on: https://go-review.googlesource.com/c/go/+/390694
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Type inference for types was always a "nice to have" feature.
Given the under-appreciated complexity of making it work in all
cases, and the fact that we don't have a good understanding of
how it might affect readability of generic code, require explicit
type arguments for generic types.
This matches the current implementation.
Change-Id: Ie7ff6293d3fbea92ddc54c46285a4cabece7fe01
Reviewed-on: https://go-review.googlesource.com/c/go/+/390577
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
This change includes several smaller changes based on feedback
received so far.
These changes were reviewed at CL 385536. The only additional
change here is to the current date in the subtitle.
Change-Id: I653eb4a143e3b86c5357a2fd3b19168419c9f432
Reviewed-on: https://go-review.googlesource.com/c/go/+/390634
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #51153
Change-Id: I4374c63498b62ba7a08f146eebd034cbd50623f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/389634
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
This template is based on CL 342070 and previous ones like it.
Continue to eagerly include often-used sections, and clarify that
the TODO is about completing the section, or removing if it turns
out not to be needed.
Move the Go 1.18 release notes to x/website, since that's the new
home for past Go release notes as of CL 291711. They're added to
x/website in CL 388556.
For #51400
Updates #47694
Change-Id: I7b5213e039ad6e14a7ff7ad486311efcecc06824
Reviewed-on: https://go-review.googlesource.com/c/go/+/388515
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alex Rakoczy <alex@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
The Go 1 compatibility guarantee permits us to break code if there is
a specification error or a bug. Emphasize that for generics.
Change-Id: I8379a14cdab9f63bb747e961ca12d1adecfc2eb4
Reviewed-on: https://go-review.googlesource.com/c/go/+/388454
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
For #45964
Change-Id: Ic66502c50ca328e944c91e710dca6c8dbc168e4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/387855
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The tag was "go-mod-vendor", which doesn't match the content.
Also move that section later, so "go mod" sections stay together.
For #47694.
Change-Id: Id4fa7ee0768682a9aadfeb1b2f1d723e7521896b
Reviewed-on: https://go-review.googlesource.com/c/go/+/387354
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Updates #47694
Change-Id: I6c1c3698fdd55fe83c756f28776d1d26dba0a9df
Reviewed-on: https://go-review.googlesource.com/c/go/+/386974
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
sed 's/the/that/g'
Change-Id: I3f539817b055d54b0ec99346555ac91b756d9ed6
GitHub-Last-Rev: 2e7df1c346
GitHub-Pull-Request: golang/go#51267
Reviewed-on: https://go-review.googlesource.com/c/go/+/386854
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
This change removes the -workfile flag and allows the go.work file path
to be set using GOWORK (which was previously read-only). This removes
the potential discrepancy and confusion between the flag and environment
variable.
GOWORK will still return the actual path of the go.work file found if it
is set to '' or 'auto'. GOWORK will return 'off' if it is set to 'off'.
For #45713Fixes#51171
Change-Id: I72eed65d47c63c81433f2b54158d514daeaa1ab3
Reviewed-on: https://go-review.googlesource.com/c/go/+/385995
Trust: Michael Matloob <matloob@golang.org>
Run-TryBot: Michael Matloob <matloob@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
The (temporary) highlights will make it easier to review the spec
in formatted form as opposed to html text.
Added a missing rule about the use of adjusted core types for
constraint type inference.
Adjusted rule for invalid embedding of interface types.
Change-Id: Ie573068d2307b66c937e803c486724175415b9c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/385535
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change moves the relevant prose of the section on type parameters
into the section on type parameter lists and eliminates the former.
With this change, the section on types now exclusively describes all
Go composite types.
User-defined named types (defined types and type parameters) are
described with their declarations.
Change-Id: I3e421cd236e8801d31a4a81ff1e5ec9933e3ed20
Reviewed-on: https://go-review.googlesource.com/c/go/+/385037
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also, fixed several closing header tags and removed a duplicate "the".
(Thanks to @hopehook and Hossein Zolfi for pointing these out.)
Change-Id: I85a40ba44b8570a578bce8d211dcc5ea3901fb1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/385036
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The outcome of type inference depends critically on when function
argument type inference stops processing arguments. Describe this
and explain an example with some detail.
Also: In the section on the built-in function delete, refer to the
value rather than the type of the second argument, as it may be an
untyped constant.
Change-Id: Ice7fbb33f985afe082380b8d37eaf763238a3818
Reviewed-on: https://go-review.googlesource.com/c/go/+/385034
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I6de236442f213ab4b4f19ec881add4923d8bfd8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/385054
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Kevin Burke <kevin@burke.dev>
A basic interface is a classical Go interface containing only
methods or embedding basic interfaces.
Use this to simplify rule about what interfaces may be used
where. The term "basic interface" will also be useful when
talking about various interfaces in general.
Fix rule restricting union terms: as it was written it also
excluded interface terms with non-empty method sets due to
embedded non-interface types with methods.
Split the large section on interfaces into three smaller
pieces by introducing section titles.
Change-Id: I142a4d5609eb48aaa0f7800b5b85c1d6c0703fcb
Reviewed-on: https://go-review.googlesource.com/c/go/+/384994
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This makes the prose easier to read while being just as precise.
Change-Id: Ie46c6c5042f419de9fdeb1c75bb72b5a40c37073
Reviewed-on: https://go-review.googlesource.com/c/go/+/384774
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
This change only shuffles sections for better organization; there
are no other changes except title and link adjustments.
Until now, the sections on underlying types and method sets were
immediately following the introduction of types. As it becomes
necessary to introduce the notion of a core type more centrally,
the natural place is immediately following the section on underlying
types. All together, these sections, immediately after the introduction
of types, would distract from purpose of the section on types, which
is to introduce the various types that Go offers.
The more natural place for the definition of underlying, core, and
specific types is the section on properties of types and values.
To accomplish this, the section on the structure of interfaces is
split into a section on core types and one on specific types, and
the various sections are reorganized appropriately.
The new organization of the section on types now simply introduces
all Go types as follows:
- boolean types
- numeric types
- string types
- array types
- slice types
- struct types
- pointer types
- function types
- interface types
- map types
- channel types
- type parameters
The new organization of the section on properties of types and values
is as follows:
- underlying types
- core types
- specific types
- type identity
- assignability
- representability
- method sets
Change-Id: I59e4d47571da9d4c89d47d777f5353fb1c5843e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/384623
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Includes a few minor cosmetic changes.
Change-Id: I6c307d958b47d83671142688630ea7835168439f
Reviewed-on: https://go-review.googlesource.com/c/go/+/384622
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These TODOs were originally removed in CL 368794.
Updates #47694
Change-Id: I39d5c0ce5f96adbbc466585a5831f721057dbed5
Reviewed-on: https://go-review.googlesource.com/c/go/+/384619
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Fixes#51110.
Change-Id: I11370417f1ef435b05dfab18eeabc2c3c1b7b8a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/384674
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add corresponding rules and a couple of examples.
Fixes#50202.
Change-Id: I4287b5e2d0fd29a0c871795e07f1bb529c9c6004
Reviewed-on: https://go-review.googlesource.com/c/go/+/384240
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change in terminology prevents potential confusion
that migth be caused by associating "structural type"
with "structural typing"; the two are not connected.
Also, adjusted introductory paragraph of section on
constraint type inference: type inference goes in both
directions, from type parameter to core type and vice
versa. The previous description was not quite accurate.
Change-Id: If4ca300f525eea660f68486302619aa6ad5dbc2c
Reviewed-on: https://go-review.googlesource.com/c/go/+/384238
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #47694.
Change-Id: I5f6850e171f574a5342671778df854dc68a5148f
Reviewed-on: https://go-review.googlesource.com/c/go/+/384554
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alex Rakoczy <alex@golang.org>
Trust: Alex Rakoczy <alex@golang.org>
Run-TryBot: Alex Rakoczy <alex@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
The terms "integer type", "floating-point type", and "complex type"
are used frequently in the spec but are not explicitly (only indirectly)
defined.
Slightly rephrased the section on numeric types and introduce these
terms explicitly. Add links to this section.
Change-Id: I3fb888933bece047da8b356b684c855618e9aee4
Reviewed-on: https://go-review.googlesource.com/c/go/+/384157
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I119cfb1a0da9af89ced78935b8fcdfdb8d9b4ab6
Reviewed-on: https://go-review.googlesource.com/c/go/+/383794
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
It has moved to golang.org/x/exp/constraints. Perhaps it will move
back to the standard library in a future release.
For golang/go#45458Fixesgolang/go#50792
Change-Id: I93aa251a7afe7b329a3d3faadc0c5d6388b1f0e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/382460
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
For #47694.
For #50912.
For #50937.
Change-Id: I3fae6c8dbbd61a45e669b8fb0c18ac76f2183963
Reviewed-on: https://go-review.googlesource.com/c/go/+/381967
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: Ic338788d6410ed0d09ad129811377ee9ce5ed496
Reviewed-on: https://go-review.googlesource.com/c/go/+/367954
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This reverts CL 380854.
Per the conluding discussions on #50791. A follow-up will
document `comparable` more thoroughly.
For #50791.
Change-Id: I15db9051784a012f713e28d725c3b8bbfeb40569
Reviewed-on: https://go-review.googlesource.com/c/go/+/381076
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Mostly from CL 367954.
Change-Id: Id003b0f785a286a1a649e4d6e8c87d0418a36545
Reviewed-on: https://go-review.googlesource.com/c/go/+/379920
Trust: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Robert Griesemer <gri@golang.org>
This reverts CL 376414.
For #47694.
For #50481.
Change-Id: Ie73961046e52e6e5d3262ef0aeaa24bec7eaa937
Reviewed-on: https://go-review.googlesource.com/c/go/+/379835
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It was removed in CL 378576.
For #50501
Change-Id: I26b8f0e99a40fa5c616aa4849a6ab15dd0d072f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/379314
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Bryan Mills <bcmills@google.com>
Introduce a (local) notion of a set of representative types,
which serves as a representation/approximation of an
interface's actual type set. If the set of representative
types is is non-empty and finite, it corresponds to the set
of specific types of the interface.
In the implementation, the set of representative types serves
as a finite representation of an interface's type set, together
with the set of methods.
Change-Id: Ib4c6cd5e17b81197672e4247be9737dd2cb6b56f
Reviewed-on: https://go-review.googlesource.com/c/go/+/376834
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #47694.
Change-Id: I00862f987a0ff9f71e0295ce4320e6f9a6a4332f
Reviewed-on: https://go-review.googlesource.com/c/go/+/376414
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Problem pointed out on golang-nuts mailing list.
Change-Id: If1c9b22e1ed7b4ec7ebcaadc80fa450333e6856c
Reviewed-on: https://go-review.googlesource.com/c/go/+/375799
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The release notes explicitly refer to sections updated
for generics in the spec but then point to the old spec
which is very confusing for beta users.
For #47694
Change-Id: I5b555db3543cc32f088a8b267ec3f1195a52a812
Reviewed-on: https://go-review.googlesource.com/c/go/+/373174
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The change clarifies in the release notes for go1.18 that the variable
is for compilation and references the microarchitecture description in
the Go Wiki,
https://golang.org/wiki/MinimumRequirements#amd64,
and references the same information in the output of go help
environment.
Fixes#50174
Change-Id: I6a7d5a06f48463a810c96cc9c76fe66113d5147c
Reviewed-on: https://go-review.googlesource.com/c/go/+/372194
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
For #47694
For #48052
Change-Id: I136be9b498033309d876099aae16bad330555416
Reviewed-on: https://go-review.googlesource.com/c/go/+/373774
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
For #47694
Sorry about that! I guess the autocompleter in VSCode auto-closed the paragraph and I didn't notice.
Change-Id: I1e834e47deb708cd5285d26201a442305f8c3b24
GitHub-Last-Rev: ab88731551
GitHub-Pull-Request: golang/go#50305
Reviewed-on: https://go-review.googlesource.com/c/go/+/374014
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
For #47694
Change-Id: I9f4838100741d3ba13e9374e70466fa405c6e4d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/372634
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
For #47694
Change-Id: I9af871a4a45b002e72629904011aac8f076617f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/372974
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Robert Griesemer <gri@golang.org>
The new description matches the implementation (CL 370774).
Also, in the section on type constraints, use "defines" instead of
"determines" because the constraint interface defines the type set
which is precisely the set of acceptable type arguments.
For #49482.
Change-Id: I6f30f49100e8ba8bec0a0f1b450f88cae54312eb
Reviewed-on: https://go-review.googlesource.com/c/go/+/372874
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #49602.
Change-Id: I0d3ff8f087dffb3409918494147fd1dceff7514d
Reviewed-on: https://go-review.googlesource.com/c/go/+/372694
Trust: Robert Griesemer <gri@golang.org>
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For #47694
Change-Id: Ibf38eabcb78abc563fcf77e2b566175a18c06fa3
Reviewed-on: https://go-review.googlesource.com/c/go/+/372114
Trust: Ian Lance Taylor <iant@golang.org>
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In release notes for Go 1.18, fix typo in changes for package testing to
correctly document the change in CL 343883.
Change-Id: I40d92858ed3f74554a094466c06771f83dd81942
Reviewed-on: https://go-review.googlesource.com/c/go/+/371616
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Mui <cherryyz@google.com>
It is a new package and seems a major change.
Updates #47694.
Change-Id: If854e494e28bcd1e79c99e59119755b9cb6793d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/371816
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
There doesn't seem anything that still needs to de done there.
Updates #47694.
Change-Id: I7909f566638332f3904d20a34f61d371af1d2da2
Reviewed-on: https://go-review.googlesource.com/c/go/+/371754
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Trust: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Alex Rakoczy <alex@golang.org>
As written, the conversion P(x), where P and the type
of x are type parameters with identical underlying types
(i.e., identical constraints), is valid. However, unless
the type of x and P are identical (which is covered with
the assignability rule), such a conversion is not valid
in general (consider the case where both type parameters
are different type parameters with constraint "any").
This change adjusts the rules to prohibit type parameters
in this case. The same reasoning applies and the analogue
change is made for pointer types.
The type checker already implements these updated rules.
Change-Id: Id90187900cb2820f6a0a0cf582cf26cdf8addbce
Reviewed-on: https://go-review.googlesource.com/c/go/+/371074
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
cmd/vet has several precision improvements for the checkers copylock, printf, sortslice, testinggoroutine, and tests. Adds a high level mention in the release notes and an example of string constant concatenation.
Updates #47694
Change-Id: I7a342a57ca3fd9e2f3e8ec99f7b647269798317f
Reviewed-on: https://go-review.googlesource.com/c/go/+/370734
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Trust: Tim King <taking@google.com>
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Also update some other go/types release notes to use the present tense.
Updates #47694
Change-Id: I654371c065e76fd5d22679d0d3c1a81bc3d1e513
Reviewed-on: https://go-review.googlesource.com/c/go/+/370235
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
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This CL reorders the bullet points in the generics section to more
closely match what I think users will consider most important. I put
the ~ token before the mention of ~T in interfaces to avoid a forward
reference, though I wonder if we actually want to spent a couple more
sentences saying what union and ~T types are, since most people are
going to care about that a lot more than they care about the low-level
detail that there's a new token.
For #47694.
Change-Id: Ib84f096ef6346a711801268ce362b64fa423d3f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/369734
Trust: Austin Clements <austin@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
NewTypeList was not part of the go/types API proposal, and was left in
by accident. It also shouldn't be necessary, so remove it.
Updates #47916
Change-Id: I4db3ccf036ccfb708ecf2c176ea4921fe68089a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/369475
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
For #47694
Change-Id: Iee4fda069a56ea4436b8aa32e2605f3349d7c154
Reviewed-on: https://go-review.googlesource.com/c/go/+/369334
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Also, move it up in the document.
Updates #47694
Change-Id: I927c4c845089a5c22e2c5b5f3de1831c04c6d990
Reviewed-on: https://go-review.googlesource.com/c/go/+/369102
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The number of involved CLs is too large (hundreds) so
no CLs are mentioned in (html) comments.
Updates #47694
Change-Id: I655d800a1e56a71e9d70a190f1c42c17baf6861e
Reviewed-on: https://go-review.googlesource.com/c/go/+/369099
Trust: Robert Griesemer <gri@golang.org>
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Also make a few small formatting fixes.
Change-Id: Iad99d030312393af3b6533f2cd00f09aea0f2a7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/369074
Trust: Katie Hockman <katie@golang.org>
Run-TryBot: Katie Hockman <katie@golang.org>
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Reviewed-by: Robert Griesemer <gri@golang.org>
For #44853
For #47694
Change-Id: Ia76246218b1361d8bdf510bbfc5178c83cdd3eec
Reviewed-on: https://go-review.googlesource.com/c/go/+/368834
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This is based off Michael's notes.
Updates #47694
Change-Id: I6e7944f85b776e8481829a2fafd177a49557c6ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/368156
Trust: Jeremy Faller <jeremy@golang.org>
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Reviewed-by: Michael Knyszek <mknyszek@google.com>
This description is based on https://golang.org/cl/321490.
Updates #47694
Change-Id: I48656cd487d2fccf0b0d3390f350f1bc6f2b0080
Reviewed-on: https://go-review.googlesource.com/c/go/+/365738
Trust: Jeremy Faller <jeremy@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
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Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Change-Id: I562d4648756e710020ee491f3801896563a89baa
Reviewed-on: https://go-review.googlesource.com/c/go/+/367395
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We want to support some special cases for index expressions, len, and
cap on operands of type parameters (such as indexing a value constrained
by byte slices and strings), hence the extra rules.
Change-Id: I4a07dc7e64bb47361b021d606c52eae1784d5430
Reviewed-on: https://go-review.googlesource.com/c/go/+/366814
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>
- fix definition of "specific types" and add more examples
- state that a parameterized function must be instantiated
when used as a function value
- remove duplicate word ("can can" -> "can")
Thanks to @danscales for finding these.
Change-Id: Ideb41efc35a3e67694d3bc97e462454feae37c44
Reviewed-on: https://go-review.googlesource.com/c/go/+/367394
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
For #47694.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Change-Id: I38c2fd9b57fbbacf220a2bc679f67e2dfdcc7cb1
Reviewed-on: https://go-review.googlesource.com/c/go/+/367514
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
This change corrects the link `Instantiantions` to `Instantiations` in the spec.
Change-Id: Ib0ed03420ae401d20af1ea723c5487018b2f462d
GitHub-Last-Rev: b84316c818
GitHub-Pull-Request: golang/go#49816
Reviewed-on: https://go-review.googlesource.com/c/go/+/367274
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Change-Id: I11111b3617673be94508128489aed6488d518537
Reviewed-on: https://go-review.googlesource.com/c/go/+/366834
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I5ffc7f26236487070447eaa0f6b14d1fab44c3c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/366794
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I2770da87b4c977b51dfa046f2f08283917675e1c
Reviewed-on: https://go-review.googlesource.com/c/go/+/365916
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
Change-Id: I7bfddf4be0d1d95419f312bb349ae2e16b74b795
Reviewed-on: https://go-review.googlesource.com/c/go/+/365915
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I3c4d8bdb5e92ee7fdca9593fb043f94f467755e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/365434
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I4423a059527066c4418c195911f8184dfd3f5a15
Reviewed-on: https://go-review.googlesource.com/c/go/+/365914
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The notion of specific types will be used to define rules for
assignability, convertability, etc. when type parameters are
involved.
Change-Id: Ic5c134261e2a9fe05cdf25efd342f052458ab5c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/366754
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Thanks to @danscales for noticing the mistake.
Change-Id: I547ee80a78419765b82d39d7b34dc8d3bf962c35
Reviewed-on: https://go-review.googlesource.com/c/go/+/366215
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
Fixes#49214.
For #47694.
Change-Id: Iba68ed17bfd81890309b6a6732087f87a03e1350
Reviewed-on: https://go-review.googlesource.com/c/go/+/366274
Trust: Robert Griesemer <gri@golang.org>
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This change introduces the notion of a structural interface
and its corresponding structural type.
Change-Id: Ib5442dfd04cb5950b4467428cae51849f8922272
Reviewed-on: https://go-review.googlesource.com/c/go/+/365474
Trust: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
- add section on type parameters
- added two sections on the scope of type parameters
- expanded general section on types accordingly
- introduced the notion of a named type which will
help in simplifying various rules (subsequent CLs)
Change-Id: I49c1ed7d6d4f951d751f0a3ca5dfb637e49829f2
Reviewed-on: https://go-review.googlesource.com/c/go/+/365414
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I29e9188a0fa1326c2755a9b86aeb47feaa8019be
Reviewed-on: https://go-review.googlesource.com/c/go/+/365274
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
- fixed a typo in the method set section
- express in the syntax that ~T denotes an underlying type
- be more precise when talking about types vs type terms
- refer to "unions" rather than "union expressions"
- make it clear in the spec title that this is WIP
Change-Id: I9b2c4b1f77bc50dd574ed6893bedd40529c320fc
Reviewed-on: https://go-review.googlesource.com/c/go/+/365154
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is the first of several CLs that update the existing
Go 1.17 spec for type parameters.
This CL updates the section on method sets and interface types.
It also adds "any", "comparable" to the list of predeclared
identifiers.
Change-Id: I0ce25dc02791c33150c0d949528512610faf3eab
Reviewed-on: https://go-review.googlesource.com/c/go/+/362999
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also mention local types restriction.
We probably want to say more at some point, this is just a
placeholder to start.
Update #47631
Change-Id: I828e451e1e8504d21cb55c7132e9cb330b160a54
Reviewed-on: https://go-review.googlesource.com/c/go/+/364134
Trust: Keith Randall <khr@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
For #47694
Change-Id: I39594c273aeb038702457587ee1c46e4b3920bb6
Reviewed-on: https://go-review.googlesource.com/c/go/+/363359
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Trust: Jeremy Faller <jeremy@golang.org>
Thanks for jtagcat@ for finding this.
Change-Id: If7324808edbae19ec8bf503b04e0426f3fb3b47a
Reviewed-on: https://go-review.googlesource.com/c/go/+/363394
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
This PR adds a note into the Go 1.18 changelog for CL 330852.
Updates #46923.
Change-Id: I99150e9275ce23fcf3697d6a22ac216818223c74
GitHub-Last-Rev: b2772ce68b
GitHub-Pull-Request: golang/go#49258
Reviewed-on: https://go-review.googlesource.com/c/go/+/360297
Trust: Roland Shoemaker <roland@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
For #47327
Change-Id: I50418c0d017c4e90a2c13d26945ee639079e4e33
Reviewed-on: https://go-review.googlesource.com/c/go/+/363174
Trust: Bryan C. Mills <bcmills@google.com>
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Reviewed-by: Paschalis Tsilias <paschalistsilias@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This will allow us to compare the changes made for Go 1.18.
Change-Id: I1456270b201967f5cb05e66cec556939e6e33265
Reviewed-on: https://go-review.googlesource.com/c/go/+/362894
Trust: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
Updates #48367.
Change-Id: Ib8fc6d9dd7c3c6a70fefe077615f51a71d9c42ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/361899
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
A small touchup after CL 361894.
For #47694.
Change-Id: Ifc161516f897f727195d21351a3c8eda7b6e327e
Reviewed-on: https://go-review.googlesource.com/c/go/+/361895
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Carlos Amedee <carlos@golang.org>
For #47694.
Change-Id: Ia80a1859bd0fc6f08d27293f519c22fd9a804fd2
Reviewed-on: https://go-review.googlesource.com/c/go/+/361894
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Carlos Amedee <carlos@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
In modules that specify 'go 1.17' or higher, the go.mod file
explicitly requires modules for all packages transitively imported by
the main module. Users tend to use 'go mod download' to prepare for
testing the main module itself, so we should only download those
relevant modules.
In 'go 1.16' and earlier modules, we continue to download all modules
in the module graph (because we cannot in general tell which ones are
relevant without loading the full package import graph).
'go mod download all' continues to download every module in
'go list all', as it did before.
Fixes#44435
Change-Id: I3f286c0e2549d6688b3832ff116e6cd77a19401c
Reviewed-on: https://go-review.googlesource.com/c/go/+/357310
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
This reverts CL 359096.
Updates #47788.
Reason for revert: -buildmode=shared may have actually been working in a few very specific cases. We should not remove -buildmode=shared until we have implemented an alternative to support those few cases.
Change-Id: Ia962b06abacc11f6f29fc29d092773be175e32f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/359575
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Change-Id: I032791a3cda1916099b0fd2955dcca4e69763660
Reviewed-on: https://go-review.googlesource.com/c/go/+/357958
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
It never worked in module mode (or with a read-only GOROOT).
A proposal to drop it was filed (and approved) in
https://golang.org/issue/47788.
Fixes#47788
Change-Id: I0c12f38eb0c5dfe9384fbdb49ed202301fa4273d
Reviewed-on: https://go-review.googlesource.com/c/go/+/359096
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Mention future versions will require the COMPAT_FREEBSD12 kernel option
set in the kernel.
For #47694.
Change-Id: Ia94c4f9dbb38c68025d3c1d12dd2e241a5480a6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/354971
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
For #43684
Change-Id: I9ce47de82203ec87e7d3683f56e6c6d61ae255f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/352151
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
gofmt is pretty heavily CPU-bound, since parsing and formatting 1MiB
of Go code takes much longer than reading that amount of bytes from
disk. However, parsing and manipulating a large Go source file is very
difficult to parallelize, so we continue to process each file in its
own goroutine.
A Go module may contain a large number of Go source files, so we need
to bound the amount of work in flight. However, because the
distribution of sizes for Go source files varies widely — from tiny
doc.go files containing a single package comment all the way up to
massive API wrappers generated by automated tools — the amount of
time, work, and memory overhead needed to process each file also
varies. To account for this variability, we limit the in-flight work
by bytes of input rather than by number of files. That allows us to
make progress on many small files while we wait for work on a handful
of large files to complete.
The gofmt tool has a well-defined output format on stdout, which was
previously deterministic. We keep it deterministic by printing the
results of each file in order, using a lazily-synchronized io.Writer
(loosly inspired by Haskell's IO monad). After a file has been
formatted in memory, we keep it in memory (again, limited by the
corresponding number of input bytes) until the output for all previous
files has been flushed. This adds a bit of latency compared to
emitting the output in nondeterministic order, but a little extra
latency seems worth the cost to preserve output stability.
This change is based on Daniel Martí's work in CL 284139, but using a
weighted semaphore and ephemeral goroutines instead of a worker pool
and batches. Benchmark results are similar, and I find the concurrency
in this approach a bit easier to reason about.
In the batching-based approach, the batch size allows us to "look
ahead" to find large files and start processing them early. To keep
the CPUs saturated and prevent stragglers, we would need to tune the
batch size to be about the same as the largest input files. If the
batch size is set too high, a large batch of small files could turn
into a straggler, but if the batch size is set too low, the largest
files in the data set won't be started early enough and we'll end up
with a large-file straggler.
One possible alternative would be to sort by file size instead of
batching: identify all of the files to be processed, sort from largest
to smallest, and then process the largest files first so that the
"tail" of processing covers the smallest files. However, that approach
would still fail to saturate available CPU when disk latency is high,
would require buffering an arbitrary amount of metadata in order to
sort by size, and (perhaps most importantly!) would not allow the
`gofmt` binary to preserve the same (deterministic) output order that
it has today.
In contrast, with a semaphore we can produce the same deterministic
output as ever using only one tuning parameter: the memory footprint,
expressed as a rough lower bound on the amount of RAM available per
thread. While we're below the memory limit, we can run arbitrarily
many disk operations arbitrarily far ahead, and process the results of
those operations whenever they become avaliable. Then it's up to the
kernel (not us) to schedule the disk operations for throughput and
latency, and it's up to the runtime (not us) to schedule the
goroutines so that they complete quickly.
In practice, even a modest assumption of a few megabytes per thread
seems to provide a nice speedup, and it should scale reasonably even
to machines with vastly different ratios of CPU to disk. (In practice,
I expect that most 'gofmt' invocations will work with files on at most
one physical disk, so the CPU:disk ratio should vary more-or-less
directly with the thread count, whereas the CPU:memory ratio is
more-or-less independent of thread count.)
name \ time/op baseline.txt 284139.txt simplified.txt
GofmtGorootCmd 11.9s ± 2% 2.7s ± 3% 2.8s ± 5%
name \ user-time/op baseline.txt 284139.txt simplified.txt
GofmtGorootCmd 13.5s ± 2% 14.4s ± 1% 14.7s ± 1%
name \ sys-time/op baseline.txt 284139.txt simplified.txt
GofmtGorootCmd 465ms ± 8% 229ms ±28% 232ms ±31%
name \ peak-RSS-bytes baseline.txt 284139.txt simplified.txt
GofmtGorootCmd 77.7MB ± 4% 162.2MB ±10% 192.9MB ±15%
For #43566
Change-Id: I4ba251eb4d188a3bd1901039086be57f0b341910
Reviewed-on: https://go-review.googlesource.com/c/go/+/317975
Trust: Bryan C. Mills <bcmills@google.com>
Trust: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Thanks to @bodar (Github) for finding this.
Fixes#48422.
Change-Id: I031c3d82a02db1d204e2b86b494d89784d37f073
Reviewed-on: https://go-review.googlesource.com/c/go/+/350409
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
CL 85215 added prose to provide some minimal intuition for the
definition of a "terminating statement". While the original definition
was perfectly fine, the added prose was actually incorrect: If the
terminating statement is a goto, it might jump to a labeled statement
following that goto in the same block (it could be the very next
statement), and thus a terminating statement does not in fact
"prevent execution of all statements that lexically appear after
it in the same block".
Rather than explaining the special case for gotos with targets that
are lexically following the goto in the same block, this CL opts for
a simpler approach.
Thanks to @3bodar (Github) for finding this.
Fixes#48323.
Change-Id: I8031346250341d038938a1ce6a75d3e687d32c37
Reviewed-on: https://go-review.googlesource.com/c/go/+/349172
Trust: Robert Griesemer <gri@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
