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Numeric literals are not handled properly

See original GitHub issue

RoslynQuoter doesn’t generate the correct code for numeric literals. For example, consider this expression:

new object[] { 42, 42.0, 42f, 42m, 42.0m, 42.00m }

Those six values all have different syntax and are also different values. But the code generated by RQ is:

ArrayCreationExpression(
        ArrayType(PredefinedType(Token(SyntaxKind.ObjectKeyword))).WithRankSpecifiers(
            SingletonList<ArrayRankSpecifierSyntax>(
                ArrayRankSpecifier(
                    SingletonSeparatedList<ExpressionSyntax>(OmittedArraySizeExpression())))))
    .WithInitializer(
        InitializerExpression(
            SyntaxKind.ArrayInitializerExpression,
            SeparatedList<ExpressionSyntax>(
                new SyntaxNodeOrToken[]
                {
                    LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(42)),
                    Token(SyntaxKind.CommaToken),
                    LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(42)),
                    Token(SyntaxKind.CommaToken),
                    LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(42)),
                    Token(SyntaxKind.CommaToken),
                    LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(42)),
                    Token(SyntaxKind.CommaToken),
                    LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(42.0)),
                    Token(SyntaxKind.CommaToken),
                    LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(42.00))
                }))).NormalizeWhitespace()

Evaluating this results in:

new object[]{42, 42, 42, 42, 42, 42}

I think that RQ should generate code that at least preserves semantics. (Ideally, it should preserve the exact syntax used, but I think that’s less important.)

Issue Analytics

State:
Created 6 years ago
Reactions:1
Comments:6 (6 by maintainers)

Top GitHub Comments

2reactions

svickcommented, May 30, 2021

@KirillOsenkov It’s much better, but still not fully fixed. The generated code now is:

ArrayCreationExpression(
    ArrayType(
        PredefinedType(
            Token(SyntaxKind.ObjectKeyword)))
    .WithRankSpecifiers(
        SingletonList<ArrayRankSpecifierSyntax>(
            ArrayRankSpecifier(
                SingletonSeparatedList<ExpressionSyntax>(
                    OmittedArraySizeExpression())))))
.WithInitializer(
    InitializerExpression(
        SyntaxKind.ArrayInitializerExpression,
        SeparatedList<ExpressionSyntax>(
            new SyntaxNodeOrToken[]{
                LiteralExpression(
                    SyntaxKind.NumericLiteralExpression,
                    Literal(42)),
                Token(SyntaxKind.CommaToken),
                LiteralExpression(
                    SyntaxKind.NumericLiteralExpression,
                    Literal(42.0)),
                Token(SyntaxKind.CommaToken),
                LiteralExpression(
                    SyntaxKind.NumericLiteralExpression,
                    Literal(42f)),
                Token(SyntaxKind.CommaToken),
                LiteralExpression(
                    SyntaxKind.NumericLiteralExpression,
                    Literal(42m)),
                Token(SyntaxKind.CommaToken),
                LiteralExpression(
                    SyntaxKind.NumericLiteralExpression,
                    Literal(42.0m)),
                Token(SyntaxKind.CommaToken),
                LiteralExpression(
                    SyntaxKind.NumericLiteralExpression,
                    Literal(42.00m))})))
.NormalizeWhitespace()

This produces:

new object[]{42, 42, 42F, 42M, 42.0M, 42.00M}

So the only remaining problematic case is double, which should be fixed if https://github.com/dotnet/roslyn/issues/23403 is fixed. I guess this means you can now either close this issue as a duplicate of the Roslyn issue, or keep it open if you think workaround in RQ would be worth it.

1reaction

svickcommented, Nov 27, 2017

I suspect that using the SyntaxFactory.Literal(string text, SomeType value) overloads is going to work.

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