When parsing a declaration of the form
type a [b[c]]d
where a, b, c, d stand for identifiers, b[c] is parsed as a type
constraint (because an array length must be constant and an index
expression b[c] is never constant, even if b is a constant string
and c a constant index - this is crucial for disambiguation of the
various possibilities).
As a result, the error message referred to a missing type parameter
name and not an invalid array declaration.
Recognize this special case and report both possibilities (because
we can't be sure without type information) with the new error:
"missing type parameter name or invalid array length"
ALso, change the previous error message
"type parameter must be named"
to
"missing type parameter name"
which is more fitting as the error refers to an absent type parameter
(rather than a type parameter that's somehow invisibly present but
unnamed).
Fixes#60812.
Change-Id: Iaad3b3a9aeff9dfe2184779f3d799f16c7500b34
Reviewed-on: https://go-review.googlesource.com/c/go/+/538856
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
- Use "expected X" rather then "expecting X".
- Report a better error when a type argument list is expected.
- Adjust various tests.
For #54511.
Change-Id: I0c5ca66ecbbdcae1a8f67377682aae6b0b6ab89a
Reviewed-on: https://go-review.googlesource.com/c/go/+/425734
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Type parameter lists starting with the form [name *T|...] or
[name (X)|...] may look like an array length expression [x].
Only after parsing the entire initial expression and checking
whether the expression contains type elements or is followed
by a comma can we make the final decision.
This change simplifies the existing parsing strategy: instead
of trying to make an upfront decision with limited information
(which is insufficient), the parser now parses the start of a
type parameter list or array length specification as expression.
In a second step, if the expression can be split into a name
followed by a type element, or a name followed by an ordinary
expression which is succeeded by a comma, we assume a type
parameter list (because it can't be an array length).
In all other cases we assume an array length specification.
Fixes#49482.
Change-Id: I269b6291999bf60dc697d33d24a5635f01e065b9
Reviewed-on: https://go-review.googlesource.com/c/go/+/402256
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
- Use .go suffix for test files as go fmt doesn't descend into testdata
directories.
- Move test files from testdata/go2 into testdata directory.
- Delete some test files that contained type-checker ERROR markers that
were ignored by the TestParseGo2 test but would be considered by the
TestSyntaxErrors test if the files were moved unchanged into the
testdata directory.
- Remove one (type checker) ERROR marker in testdata/slices.go to make
it pass the syntax error tests.
- Delete TestParseGo2 test. There's enough coverage with the existing
TestSyntaxErrors test.
- Add missing copyright notice to testdata/chans.go and gofmt the file.
Change-Id: I449913fe1bd2119987ba33f7152e5e4ba5f3fe31
Reviewed-on: https://go-review.googlesource.com/c/go/+/396518
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Robert Griesemer