private static SyntaxNode ProcessMatch(SyntaxNode node, Scope scope)
{
var switchExpr = node as SwitchStatementSyntax;
if (switchExpr == null)
{
scope.AddError("match01", "malformed match", node);
return(node);
}
//store items to simplify
var cases = new List <ExpressionSyntax>();
var statements = new List <StatementSyntax>();
var defaultStatement = null as StatementSyntax;
foreach (var section in switchExpr.Sections)
{
bool isDefault;
var expr = caseExpression(section.Labels, switchExpr.Expression, out isDefault);
StatementSyntax statement = caseStatement(section.Statements);
if (isDefault && section.Labels.Count == 1)
{
defaultStatement = statement;
}
else
{
cases.Add(expr);
statements.Add(statement);
if (isDefault)
{
defaultStatement = statement;
}
}
}
//convert cases to ifs
Debug.Assert(cases.Count == statements.Count);
var last = cases.Count - 1;
IfStatementSyntax result = CSharp.IfStatement(cases[last], statements[last]);
if (defaultStatement != null)
{
result = result.WithElse(CSharp.ElseClause(defaultStatement));
}
for (int i = last - 1; i >= 0; i--)
{
result = CSharp.IfStatement(cases[i], statements[i])
.WithElse(CSharp.ElseClause(result));
}
return(result);
}
private static SyntaxNode IfElseStatement(RParser.IfElseStatementContext ifStatement, Func <ParserRuleContext, Scope, SyntaxNode> transform, Scope scope)
{
if (!topLevel(ifStatement))
{
throw new NotImplementedException();
}
var exprs = ifStatement.expr();
var cond = (ExpressionSyntax)transform(exprs[0], scope);
var @if = parseBlock(exprs[1], transform, scope);
var @else = parseBlock(exprs[2], transform, scope);
return(@ifelse.Get <IfStatementSyntax>(cond)
.WithStatement(@if)
.WithElse(CSharp.ElseClause(
@else)));
}