public override SyntaxNode Visit(SyntaxNode node)
{
if (node == null)
{
return(null);
}
var result = node;
foreach (var transformer in _transformers)
{
var before = result;
result = transformer(result, _scope);
if (result != before)
{
result = RoslynCompiler.UpdateExcessId(result, before);
}
if (result == null)
{
return(null);
}
}
return(base.Visit(result));
}
//rewriters
private Func <SyntaxNode, Scope, LookAheadResult> CheckCodeExtension(SyntaxNode original, SyntacticalExtension <SyntaxNode> extension)
{
return((node, scope) =>
{
var code = node as BlockSyntax;
if (code == null)
{
return new LookAheadResult {
Matched = false
}
}
;
_lookahead = null;
extension.Body = base.Visit(code);
SyntaxNode resulSyntaxNode = null;
if (original is LocalDeclarationStatementSyntax)
{
extension.Kind = ExtensionKind.Expression;
resulSyntaxNode = extension.Handler(node, scope, extension);
if (!(resulSyntaxNode is ExpressionSyntax))
{
//td: error, expecting expression
return new LookAheadResult {
Matched = false
};
}
var localDecl = original as LocalDeclarationStatementSyntax;
resulSyntaxNode = localDecl
.WithDeclaration(localDecl.Declaration
.WithVariables(CSharp.SeparatedList(new[] {
localDecl.Declaration.Variables[0]
.WithInitializer(localDecl.Declaration.Variables[0].Initializer
.WithValue((ExpressionSyntax)resulSyntaxNode))
})))
.WithSemicolonToken(CSharp.ParseToken(";"));
}
else if (original is ExpressionStatementSyntax)
{
var exprStatement = original as ExpressionStatementSyntax;
var assignment = exprStatement.Expression as AssignmentExpressionSyntax;
if (assignment != null)
{
extension.Kind = ExtensionKind.Expression;
resulSyntaxNode = extension.Handler(node, scope, extension);
if (!(resulSyntaxNode is ExpressionSyntax))
{
//td: error, expecting expression
return new LookAheadResult {
Matched = false
};
}
resulSyntaxNode = exprStatement
.WithExpression(assignment
.WithRight((ExpressionSyntax)resulSyntaxNode))
.WithSemicolonToken(CSharp.ParseToken(";"));
}
else
{
resulSyntaxNode = extension.Handler(node, scope, extension);
if (resulSyntaxNode != null)
{
resulSyntaxNode = RoslynCompiler.UpdateExcessId(resulSyntaxNode, node);
}
}
}
else
{
throw new NotImplementedException();
}
return new LookAheadResult
{
Matched = true,
Result = resulSyntaxNode,
};
});
}