/// <summary>
/// Creates a new instance of <see cref="SwitchStatement" />, copying all the cases of the specified statement, and adding cases for all the literals in the specified sequence.
/// </summary>
/// <param name="statement">the statement to copy the cases from.</param>
/// <param name="values">a sequence of literals for which to add cases.</param>
/// <returns>a new instance of <see cref="SwitchStatement" />.</returns>
public static SwitchStatement Case(this SwitchStatement statement, IEnumerable<Expression> values)
{
if (statement == null)
{
throw new ArgumentNullException("statement");
}
if (values != null)
{
SwitchStatement @switch = new SwitchStatement(
statement.Expression,
statement.Cases.Union(values.Select(value => new CaseStatement(value))));
return @switch;
}
return statement;
}
/// <summary>
/// Creates a new instance of <see cref="SwitchStatement" />, copying all the cases of the specified statement, and adding a default case.
/// </summary>
/// <param name="statement">The statement to copy the cases from.</param>
/// <returns>a new instance of <see cref="SwitchStatement" />.</returns>
public static SwitchStatement Default(this SwitchStatement statement)
{
return(Case(statement, new Expression[] { null }));
}
/// <summary>
/// Creates a new instance of <see cref="SwitchStatement" />, copying all the cases of the specified statement, replacing the last case with one that adds the specified statements.
/// </summary>
/// <param name="statement">The switch statement to copy all cases from.</param>
/// <param name="statements">A sequence of statements to append to the last case.</param>
/// <returns>a new instance of <see cref="SwitchStatement" /></returns>
/// <remarks>
/// The specified instance of <see cref="SwitchStatement" /> must already have at least one case for this method to succeed.
/// </remarks>
public static SwitchStatement Do(this SwitchStatement statement, IEnumerable<Statement> statements)
{
if (statement == null)
{
throw new ArgumentNullException("statement");
}
if (!statement.Cases.Any())
{
throw new InvalidOperationException("Can't invoke Do() on a switch statement without cases.");
}
SwitchStatement @switch = new SwitchStatement(statement.Expression, statement.Cases);
if (statements != null)
{
int lastIndex = @switch.Cases.Count - 1;
CaseStatement lastCase = @switch.Cases[lastIndex];
CaseStatement newLast = new CaseStatement(lastCase.Value, lastCase.Statements.Union(statements));
@switch.Cases[lastIndex] = newLast;
}
return @switch;
}