/*
* => [captures...] expression
* or
* => [captures...] { code... }
* or
* (parameters...) => [captures...] expression
* or
* (parameters...) => [captures...] { code... }
*/
LambdaExpression ParseLambda(TupleExpression argumentList = null)
{
var lambda = LambdaExpression.Create(unit.Location);
// Parse parameter list
if (argumentList == null || argumentList.Count == 0)
{
if (unit.Match(LoreToken.OpenParen))
{
var parameters = ParseDeclarationArgumentList();
lambda.SetParameters(parameters);
}
}
else
{
var lst = new List <NamedParameter> ();
foreach (var argument in argumentList.Items)
{
var name = argument as NameExpression;
if (name == null)
{
throw LoreException.Create(unit.Location).Describe($"Invalid parameter list in lambda declaration.");
}
lst.Add(NamedParameter.Create(name));
}
lambda.SetParameters(lst);
}
// Expect arrow operator
unit.Expect(LoreToken.Operator, "=>");
// Create master code block
CodeBlock master = CodeBlock.Create(unit.Location);
// Parse captures
if (unit.Match(LoreToken.OpenBracket))
{
// Parse captures
unit.Expect(LoreToken.OpenBracket);
while (!unit.Match(LoreToken.CloseBracket))
{
var lex = unit.Read();
var capture = Capture.Create(unit, lex);
master.AddCapture(capture);
}
unit.Expect(LoreToken.CloseBracket);
}
// Parse block
if (unit.Match(LoreToken.OpenBrace))
{
var block = ParseBlockWithoutCaptures();
// Merge captures
master.Merge(block);
}
// Or parse expression
else
{
// Create return statement for the result of the expression
var retstmt = ReturnStatement.Create(unit.Location);
retstmt.SetExpression(ParseExpression());
// Create a new block with the return statement
var block = CodeBlock.Create(unit.Location);
block.AddChild(retstmt);
// Merge captures
master.Merge(block);
}
// Set the lambda body
lambda.SetBody(master);
Console.WriteLine(lambda);
return(lambda);
}
public virtual void Accept(ReturnStatement stmt) => Update(stmt);