private static Task <Document> ConvertSwitchExpressionToSwitchStatement(
Document document,
SwitchExpressionSyntax switchExpression,
CancellationToken cancellationToken)
{
IEnumerable <SwitchSectionSyntax> sections = switchExpression.Arms.Select((arm, i) =>
{
SyntaxToken separator = switchExpression.Arms.GetSeparator(i);
SyntaxToken semicolon = Token(SyntaxKind.SemicolonToken);
if (!separator.IsMissing)
{
semicolon = semicolon.WithTriviaFrom(separator);
}
PatternSyntax pattern = arm.Pattern;
switch (pattern.Kind())
{
case SyntaxKind.ConstantPattern:
{
CaseSwitchLabelSyntax label = CaseSwitchLabel(
Token(SyntaxKind.CaseKeyword).WithLeadingTrivia(pattern.GetLeadingTrivia()),
((ConstantPatternSyntax)pattern).Expression.WithoutLeadingTrivia(),
Token(SyntaxKind.ColonToken).WithTriviaFrom(arm.EqualsGreaterThanToken));
return(SwitchSection(label, CreateStatement(arm.Expression, semicolon)));
}
case SyntaxKind.DiscardPattern:
{
DefaultSwitchLabelSyntax label = DefaultSwitchLabel(Token(SyntaxKind.DefaultKeyword), Token(SyntaxKind.ColonToken));
return(SwitchSection(label, CreateStatement(arm.Expression, semicolon)));
}
default:
{
throw new InvalidOperationException();
}
}
});
var returnStatement = (ReturnStatementSyntax)switchExpression.Parent;
SwitchStatementSyntax switchStatement = SwitchStatement(
switchExpression.SwitchKeyword.WithTriviaFrom(returnStatement.ReturnKeyword),
OpenParenToken(),
switchExpression.GoverningExpression,
CloseParenToken().WithTrailingTrivia(switchExpression.SwitchKeyword.TrailingTrivia),
switchExpression.OpenBraceToken,
sections.ToSyntaxList(),
switchExpression.CloseBraceToken);
switchStatement = switchStatement.WithFormatterAnnotation();
return(document.ReplaceNodeAsync(returnStatement, switchStatement, cancellationToken));
private static Task <Document> ConvertSwitchExpressionToSwitchStatement(
Document document,
SwitchExpressionSyntax switchExpression,
CancellationToken cancellationToken)
{
SeparatedSyntaxList <SwitchExpressionArmSyntax> arms = switchExpression.Arms;
SyntaxToken[] separators = arms.GetSeparators().ToArray();
IEnumerable <SwitchSectionSyntax> sections = arms.Select((arm, i) =>
{
PatternSyntax pattern = arm.Pattern;
ExpressionSyntax expression = arm.Expression;
SyntaxToken semicolon = Token(SyntaxKind.SemicolonToken);
SyntaxToken separator = default;
if (i < separators.Length)
{
separator = separators[i];
}
if (separator.IsKind(SyntaxKind.None) ||
separator.IsMissing)
{
semicolon = semicolon.WithTrailingTrivia(arm.GetTrailingTrivia());
expression = expression.WithoutTrailingTrivia();
}
else
{
semicolon = semicolon.WithTriviaFrom(separator);
}
SyntaxKind kind = pattern.Kind();
SwitchLabelSyntax label = default;
if (kind == SyntaxKind.ConstantPattern)
{
label = CaseSwitchLabel(
Token(SyntaxKind.CaseKeyword).WithLeadingTrivia(pattern.GetLeadingTrivia()),
((ConstantPatternSyntax)pattern).Expression.WithoutLeadingTrivia(),
Token(SyntaxKind.ColonToken).WithTriviaFrom(arm.EqualsGreaterThanToken));
}
else if (kind == SyntaxKind.DiscardPattern)
{
label = DefaultSwitchLabel(Token(SyntaxKind.DefaultKeyword), Token(SyntaxKind.ColonToken));
}
else
{
throw new InvalidOperationException();
}
StatementSyntax statement = CreateStatement(expression, semicolon);
return(SwitchSection(label, statement));
});
var returnStatement = (ReturnStatementSyntax)switchExpression.Parent;
SwitchStatementSyntax switchStatement = SwitchStatement(
switchExpression.SwitchKeyword.WithTriviaFrom(returnStatement.ReturnKeyword),
OpenParenToken(),
switchExpression.GoverningExpression,
CloseParenToken().WithTrailingTrivia(switchExpression.SwitchKeyword.TrailingTrivia),
switchExpression.OpenBraceToken,
sections.ToSyntaxList(),
switchExpression.CloseBraceToken);
switchStatement = switchStatement.WithFormatterAnnotation();
return(document.ReplaceNodeAsync(returnStatement, switchStatement, cancellationToken));