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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Threading;
using Microsoft.CodeAnalysis.CSharp.Extensions;
using Microsoft.CodeAnalysis.CSharp.Extensions.ContextQuery;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Shared.Extensions;
namespace Microsoft.CodeAnalysis.CSharp.Completion.KeywordRecommenders;
internal class IntoKeywordRecommender : AbstractSyntacticSingleKeywordRecommender
{
public IntoKeywordRecommender()
: base(SyntaxKind.IntoKeyword)
{
}
protected override bool IsValidContext(int position, CSharpSyntaxContext context, CancellationToken cancellationToken)
{
return
IsValidContextForJoin(context) ||
IsValidContextForSelect(context) ||
IsValidContextForGroup(context);
}
private static bool IsValidContextForSelect(CSharpSyntaxContext context)
{
var token = context.TargetToken;
var select = token.GetAncestor<SelectClauseSyntax>();
if (select == null)
{
return false;
}
if (select.Expression.Width() == 0)
{
return false;
}
// cases:
// select x.|
// select x.i|
var lastCompleteToken = token.GetPreviousTokenIfTouchingWord(context.Position);
if (lastCompleteToken.Kind() == SyntaxKind.DotToken)
{
return false;
}
var lastToken = select.Expression.GetLastToken(includeSkipped: true);
if (lastToken == token)
{
return true;
}
return false;
}
private static bool IsValidContextForGroup(CSharpSyntaxContext context)
{
var token = context.TargetToken;
var group = token.GetAncestor<GroupClauseSyntax>();
if (group == null)
{
return false;
}
if (group.ByExpression.Width() == 0 ||
group.GroupExpression.Width() == 0)
{
return false;
}
var lastToken = group.ByExpression.GetLastToken(includeSkipped: true);
if (lastToken == token)
{
return true;
}
return false;
}
private static bool IsValidContextForJoin(CSharpSyntaxContext context)
{
// cases:
// join a in expr o1 equals o2 |
// join a in expr o1 equals o2 i|
var token = context.TargetToken;
var join = token.GetAncestor<JoinClauseSyntax>();
if (join == null)
{
// happens for:
// join a in expr on o1 equals o2 e|
if (!token.IntersectsWith(context.Position))
{
return false;
}
token = token.GetPreviousToken(includeSkipped: true);
join = token.GetAncestor<JoinClauseSyntax>();
if (join == null)
{
return false;
}
}
var lastToken = join.RightExpression.GetLastToken(includeSkipped: true);
// join a in expr on o1 equals o2 |
if (token == lastToken &&
!lastToken.IntersectsWith(context.Position))
{
return true;
}
return false;
}
}
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