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sdk/pkg/front_end/parser_testcases/patterns/variable_final_inDeclarationContext.dart.expect
T
Paul Berry 104ac30cf4 Parser: clean up handling of variable patterns.
The listener API for variable patterns is split into three separate
functions, to handle the three separate behaviors:

- `handleAssignedVariablePattern` for variable names appearing in an
  assignment context (these assign to an existing variable upon a
  successful match).

- `handleDeclaredVariablePattern` for variable declarations appearing
  in a declaration or matching context (these cause a new variable
  name to come into scope).

- `handleWildcardPattern` for wildcards in any context (these don't
  capture the matched value).

Also, responsibility is shifted to the parser for reporting the
following error conditions:

- VariablePatternKeywordInDeclarationContext (e.g.
  `var (var x) = ...;`)

- PatternAssignmentDeclaresVariable (e.g. `[x, var y] = ...;`)

Previously these errors were detected by the implementations, and
weren't fully covering all possible error scenarios.

In the case of VariablePatternKeywordInDeclarationContext, the
listener method `handleDeclaredVariablePattern` is called instead of
`handleAssignedVariablePattern`.  This ensures that no tokens are
dropped from the analyzer AST.  The CFE uses the `inAssignmentPattern`
argument of `handleDeclaredVariablePattern` to distinguish this error
recovery case from a legitimate declared variable pattern.

Fixes #51868.

Bug: https://github.com/dart-lang/sdk/issues/51868
Change-Id: I28ec679b73d64033166721c6460be35f15e23171
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/291583
Reviewed-by: Jens Johansen <jensj@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
2023-03-30 14:12:03 +00:00

41 lines
1.6 KiB
Plaintext

Problems reported:
parser/patterns/variable_final_inDeclarationContext:2:8: Variable patterns in declaration context can't specify 'var' or 'final' keyword.
var (final y) = x;
^^^^^
beginCompilationUnit(void)
beginMetadataStar(void)
endMetadataStar(0)
beginTopLevelMember(void)
beginTopLevelMethod(, null, null)
handleVoidKeyword(void)
handleIdentifier(f, topLevelFunctionDeclaration)
handleNoTypeVariables(()
beginFormalParameters((, MemberKind.TopLevelMethod)
beginMetadataStar(x)
endMetadataStar(0)
beginFormalParameter(x, MemberKind.TopLevelMethod, null, null, null)
handleNoType(()
handleIdentifier(x, formalParameterDeclaration)
handleFormalParameterWithoutValue())
endFormalParameter(null, null, null, x, null, null, FormalParameterKind.requiredPositional, MemberKind.TopLevelMethod)
endFormalParameters(1, (, ), MemberKind.TopLevelMethod)
handleAsyncModifier(null, null)
beginBlockFunctionBody({)
beginMetadataStar(var)
endMetadataStar(0)
handleNoType(final)
handleRecoverableError(VariablePatternKeywordInDeclarationContext, final, final)
handleDeclaredVariablePattern(final, y, false)
handleParenthesizedPattern(()
handleIdentifier(x, expression)
handleNoTypeArguments(;)
handleNoArguments(;)
handleSend(x, ;)
handlePatternVariableDeclarationStatement(var, =, ;)
endBlockFunctionBody(1, {, })
endTopLevelMethod(void, null, })
endTopLevelDeclaration()
endCompilationUnit(1, )